Installation of rafters on the roof. How to properly install rafters on a gable roof

The erection of the roof is one of the most important stages of construction. The durability of the building itself and the level of comfort of living in it directly depend on the reliability of the "umbrella" from above, on its resistance to precipitation and any external influences.

Of all the variety of roof structures, gable can be attributed to the most popular, simply because of the relative simplicity of its construction. However, behind this "simplicity" lies a lot of different nuances, the need to carry out certain calculations and follow technological rules. However, this publication has the main task: to show that installing the rafters of a gable roof with your own hands is a completely doable task, even for a novice builder.

Let's walk through the process of installing rafters for such a roof together, from the basics of preliminary design to an example of practical implementation.

Basic concepts

The principle of a gable roof is already clear from the name. It is characterized by the presence of two roof slopes, in the vast majority of cases being symmetrical with respect to the ridge line. Triangular pediments are located on both end sides.

It is this scheme that is distinguished by the relative simplicity of calculation and installation. It is extremely reliable (with proper construction), provides an even distribution of loads on the walls of the building, while possessing an excellent operational safety margin. At the same time, such a roof looks, even without any frills, very nice, suitable for almost all types of roofing, and any slope angles can be attached to its slopes (naturally, within reasonable limits).

A visible disadvantage of such a roof is the presence of "deaf" zones in the attic, at the bottom of the slopes.

Sometimes architects try to add some variety to the design of gable roofs. So, for example, one of the techniques is to create an accentuated asymmetry of the slopes, both in their steepness and in length from the ridge to the cornice overhang.

Such an approach opens additional features beneficial use of the attic space. True, to independently correctly design and mount such a gable roof for an unprepared person is a task from the category of practically impossible, therefore, such a design will not be considered further in our article.

With a certain degree of convention, gable roofs include roofs with broken slope planes.

However, such structures also have features in the design and installation. Rafter systems of this type deserve a separate detailed consideration.

Attic broken roof– a great solution for a residential attic
To build a reliable truss system of this type, it will be necessary to carry out a series of calculations, carefully study the sequence of work, the technological methods used. All this in detail - in a special publication of our portal.

Structural elements of the gable roof truss system

Let us make a reservation right away that this diagram, of course, cannot reflect the entire possible variety of designs of truss systems, but the main details and nodes on it are shown quite clearly.

1 - Mauerlat. This is a board or beam that is rigidly attached to the upper end of the external load-bearing walls of the building. Its purpose is to evenly distribute the load from the entire roof system to the walls of the house, creating conditions for reliable fastening of the rafter legs at their lower fulcrum.

2 - rafter legs installed in pairs. They become the main load-bearing parts of the entire roof system - it is the rafters that set the steepness of the slopes, will be the basis for attaching the batten, roofing, and if the roof is planned to be insulated, then the entire thermal insulation "pie".

For the manufacture of rafter legs, high-quality boards or timber are used, and round timber can also be used. About the section of lumber, which will be sufficient to ensure that all possible loads can be guaranteed, will be discussed below.

The rafters may end on the Mauerlat, but more often they go beyond the perimeter of the walls of the house, forming a cornice overhang. However, lighter parts can also be used for this - the so-called "fillies", with which the rafter legs are increased to the required width of the overhang.

3 - skating run. It can be a beam, a board or even a composite structure. The run runs along the entire line of the ridge and serves to securely connect the upper points of the paired rafter legs, connect all rafter pairs in order to impart overall rigidity to the entire roof structure. In various roof options, this run can be rigidly supported by racks, or tied only to the connection node of the rafter legs.

4 - puffs (contractions, crossbars). Horizontal details of the reinforcement of the system, additionally connecting paired rafter legs to each other. Several puffs located at different heights can be used.

5 - floor beams, which will serve as the basis for mounting the floor in the attic and the ceiling from the side of the room.

6 - and this beam simultaneously plays the role of a bed. This is a beam that runs along the entire length of the roof, which is a support for installing additional reinforcement parts. truss system. The bed can be installed as shown in the figure (like a floor beam), or it can be rigidly laid on a capital partition inside the building.

7 - racks (headstock) - additional vertical supports of the rafter legs, preventing their deflection under the influence of external loads. Racks at the top can rest against the rafters themselves, or against an additional run, longitudinally connecting the rafter legs at a certain height.

8 - braces. Often, with a large length of the rafter legs, their bearing capacity is not enough, and reinforcement only with racks does not provide the necessary strength. In these cases, diagonal reinforcing elements are used, resting on the bed from below, creating an additional point of support for the rafters. The number of struts and their installation location can vary in roofs varying degrees difficulties.

Some differences between hanging and sloping gable roof systems

Gable roofs can be divided into two types of structures - with layered and hanging rafters. In addition, widely used combined systems, in which both principles of construction are combined. What is the fundamental difference?

Laminated rafter system

This design of the truss system is characterized by the presence of support on the internal capital partition in the building. On the upper end of this partition, a bed is mounted, on which drains are supported, supporting the ridge run. Thus, the rafter legs are “leaned” on a vertical support, which makes the entire system as strong as possible.

This scheme is the most popular because of its reliability and relative ease of implementation. If it is possible to create an additional point of support in the center, then why not take advantage of this? True, if it is planned to place a dwelling in the attic, then vertical racks can sometimes become a hindrance. However, their presence is also sometimes “beaten up”, using, for example, an internal light partition for mounting.

Depending on quantity and location internal partitions, the design of the layered truss system may vary. Some examples are shown in the illustration below:

Fragment “a” shows the simplest option, which, by the way, on short rafter lengths (up to 5 meters) may not even have struts shown - a row of central racks under the ridge run is enough

With an increase in the width of the building, the system naturally becomes more complicated, and additional reinforcing elements appear - puffs and struts (fragment "b").

Fragment "c" clearly demonstrates that the internal main wall does not have to be located exactly in the center, under the ridge. It is also possible such an option, as shown in the illustration, but with the condition that the displacement of the bed relative to the ridge does not exceed one meter.

Finally, fragment "d" shows how the rafter system can be supported in a large building, but with two main partitions inside. The distance between such parallel beds can reach up to a third of the width of the building.

Hanging rafter system

Graphically, this roof scheme can be depicted something like this:

It immediately catches the eye that the rafters rely only on the Mauerlat in the lower part, and then are connected to each other on the ridge. There is no additional support in the center, that is, the rafter legs seem to “hang”, which predetermines the name of such a system. This feature imposes certain restrictions on the use of hanging rafters - usually such a scheme is practiced with a distance between the bearing walls on which the Mauerlat is fixed, no more than 7 meters. Installed puffs only partially relieve the load from the external walls.

The illustration below shows several options for a hanging system. However, some of them already, rather, can be classified as combined.

Fragment "d" - hanging rafters are interconnected by a screed at the level of the Mauerlat or fixed to a powerful floor beam, forming a triangle with it. There are no other reinforcing parts. A similar scheme is permissible with a distance between walls of up to 6 meters.

Option "g" - for the same size house (up to 6 meters). The puff (crossbar) in this case is shifted upwards, and is often used for filing the ceiling of the attic.

Options "e" and "h" are designed for a span between walls up to 9 meters. Multiple puffs may be used (or top puff in combination with bottom floor beam). Another approach is to install racks under the ridge run, by analogy with a layered system. Only as a lower point of support, it is not a bed on the main partition that is used, but the racks are supported by a puff or a floor beam. To call such an option purely “hanging” is already difficult, since here is clearly a combination of parts from both designs.

To an even greater extent, such a combination of two schemes is expressed in the “and” variant, which is designed for large spans, from 9 to 14 meters. Here, in addition to the headstock, diagonal struts are also involved. Often, such trusses are generally assembled on the ground, and only then they are lifted and set in place, connected to each other, thereby forming the entire roof frame.

So, in preparation for the construction of a gable roof, it is necessary to study the principles of the device of a particular system, evaluate their advantages and disadvantages, choose the best one for your conditions and draw up a graphic working diagram. It will be needed both when purchasing the necessary material, and for the production of the installation work itself. However, drawing up a drawing should still be preceded by some calculations.

Calculation of the basic parameters of the gable roof truss system

Let's take another look at the concept of a gable roof device to highlight those parameters that need to be calculated.

So, in the process of calculation, we need to decide on the following values.

The initial data is the length of the side of the house along the gable part (highlighted in blue - F), and the length of the house along the ridge (purple - D). It is assumed that the owners have already decided on the type of roofing in advance - since there will be certain restrictions on the steepness of the roof slopes. (angle a).

The height of the ridge above the plane of the Mauerlat (H - green), or, conversely, determine the angle of the slope, starting from the planned height of the ridge.
The length of the rafter leg (blue color - L), and, if necessary, the extension of the rafter to form a cornice overhang of the required width (l).
Calculate the total loads falling on the rafter system in order to determine the optimal cross-section of lumber for the manufacture of rafters, their installation step (red color - S) and allowable length spans between anchor points. All these parameters are closely interconnected.
When these calculated values \u200b\u200bare on hand, it is already easy to draw up a graphic diagram, determine the need and optimal arrangement of reinforcement elements, and calculate the amount of material for their manufacture.

We calculate the steepness of the slope and the height of the ridge

The slope angle of the slopes can be determined by the owners according to various evaluation criteria:

For purely aesthetic reasons - when the appearance of the building becomes "at the forefront". Many people like roofs with a high ridge, but at the same time, one must not forget that the wind load increases sharply on such a roof. Yes, and materials for the manufacture of a high roof will go immeasurably more. At the same time, on steep slopes, the snow load is reduced to almost zero - it is possible that for "snowy" regions this assessment parameter may become decisive.
Their considerations for the beneficial use of the attic space. With a gable roof scheme, in order to achieve the maximum attic area, it is necessary to build slopes with a very steep slope, that is, with the same consequences as mentioned above.

Finally, there may be a completely opposite approach - for reasons of economy, make a roof structure with a minimum height in the ridge. But in this case, you will have to focus on the minimum allowable slope angles for a particular type of roofing. To reduce the steepness below the indicators recommended by the manufacturer is to “plant a bomb” in your roof, both for reasons of its strength and durability, and from the standpoint of the waterproofing qualities of the coating.

It is not difficult to calculate the height of the ridge above the floor plane (Mauerlat). At the heart of the vast majority of nodes of any roofing system is a triangle, which, in turn, obeys strict geometric (more precisely, trigonometric) laws.

So, in our case, the width of the roof along the gable line is known. If the roof is symmetrical, then the ridge will be located exactly in the middle, and for calculations, you can simply divide the width F by two (the base of the triangle f=F/2). With asymmetrical slopes, you will have to project the top of the ridge onto line F, and measure the distances f1 and f2 from it to the edge of the triangle (to the Mauerlat) on each side. Naturally, in this case, the slope of the slopes will be different.

H =f × tga

In order not to force the reader to look for the values of tangents and carry out calculations manually, a calculator is placed below, in which the necessary tabular values \u200b\u200bare already entered.

Calculator depending on the height of the roof ridge from the steepness of the slope

Enter the requested values and click the button "Calculate the length of the hypotenuse (rafter leg)"

Leg 1 (triangle height H), meters

Leg 2 (base of triangle f), meters

This result gave us the "working" length of the rafter leg. If it is planned to immediately form a cornice overhang at the expense of the rafters, then it is necessary to make an increase to the length - l. According to the laws of trigonometry, such a “makeweight” will be equal to:

K - breaded width of the cornice overhang, from the wall of the house to the edge (horizontally).

a - the angle of the steepness of the roof slope.

Even if the cornice overhang is formed due to the "filly", the calculation will help determine the required working length of these structural parts. The calculation is easier to carry out using our calculator:

Calculator for calculating the lengthening of the rafter leg for the formation of a cornice overhang.

Specify the requested data and click the button "Calculate the elongation of the rafter (working length of the filly)"

Planned width of the cornice overhang K, meters

The value of the slope slope α, degrees

At small angles of roof slope, such an elongation will differ very little from the planned width of the eaves overhang. However, as the steepness increases, the elongation of the rafter begins to increase rapidly, so this value cannot be ignored.

It remains only to sum the obtained values \u200b\u200band get the total length of the workpiece for the manufacture of rafters. Of course, it is taken with a small margin, approximately 200 ÷ 250 mm - for precise trimming after installing and fixing the rafter leg in place.

You can immediately assess whether there are blanks (lumber) of the required length on sale. On large roofs, sometimes you have to resort to splicing the rafters along the length.

Calculation of loads on the rafter system, determination of the cross section of the rafters and their installation step

We pass to the most difficult stage of calculations. It is necessary to evaluate what total loads will fall on the roof structure, how to optimally distribute them along the length load-bearing elements by varying the installation step of the rafter legs. Based on this, it will be possible to select the necessary material that will ensure the stability of the structure, without fractures or deformations, determine the reinforcement details, that is, place additional support points on the diagram that reduce the free span of the rafter leg.

The following main types of loads will be applied to the rafter system as a whole:

The weight of the rafter system itself and the roofing, and if thermal insulation is provided, then also the “insulation cake”
Loads caused by snow deposits on the roof surface.
wind loads.

There are, of course, other types of loads, and many of which are difficult to predict in advance - man-made or natural disasters, seismic shocks and more. But in order to reduce the probability of destruction of the structure from such “force majeure” phenomena, a certain operational safety margin is preliminarily laid in it.

Now - consider the loads in order.

Any roofing has its own specific gravity, requires one or another crate or certain features roof structures. The calculation calculator, which will be offered to readers below, has already entered the average values of the specific weight load from the most commonly used types roofing. Just in case, this indicator also includes the insulation of roof slopes.
Snow load depends on two quantities. First, it is calculated based on the results of long-term observations specific gravity snow cover, characteristic of a particular area. According to this parameter, the entire territory of Russia can be conditionally divided into several zones, which are indicated on the map below:

The second parameter that affects the snow load is the steepness of the roof slope. The larger the angle, the less pressure the snow masses will exert, and on slopes steeper than 60 degrees, the snow will not linger at all.

wind load. With it, it is somewhat more difficult, since you have to take into account more initial parameters. For a simplified calculation algorithm implemented in a calculator, you need to know:

- The angle of slope of the roof slopes (the larger it is, the higher the "sail" of the roof).

— The average value of wind pressure, similarly determined from the results of long-term meteorological observations for the given region. You can also determine your zone by this parameter using the corresponding map-scheme.

- The height of the building under construction is important, from the surface of the earth to the level of the ridge.

- The presence and distance of natural and artificial wind barriers are assessed. The criteria for such an assessment are well shown and described in the appropriate field of the calculator.

True, it is important to take into account one more rule here: barriers can be taken into account if their distance from the calculated building does not exceed 30 × H, where H in this case is the height of the house from the ground to the ridge. For example, for a building 8 meters high, the obstacles taken into account should be within a circle with a radius of 240 meters. If they are located further, then this will already be considered a “bare” area.

The calculator program will take into account all the data specified by the user, make the appropriate corrections, calculate the loads and lay the necessary operational safety margin.

But if you just sum up the loads, then this value is not very convenient for further actions, so it is better to use the distributed load indicator. She counts on running meter rafter leg, and directly depends on the installation step of the rafters.

Thus, by varying the value of the installation step of the rafter legs, one can observe how the distributed load changes and stop at the optimal value. And already this value will allow you to enter the table in order to determine the cross section of a board, beam or round timber, and with the allowable free span between the support points.

Calculator for calculating the distributed load on the rafter legs

Enter the requested information and click "Calculate the distributed load on the rafters"

Roof slope angle, degrees

Chosen type of roofing

Determine from the map-scheme and indicate the zone of your region according to snow load level

I II III IV V VI VII

Identify on the map and indicate the zone of your region by wind pressure level

Ia I II III IV V VI VII

Specify the location of the building

Specify the height of the roof ridge above the ground

Less than 5 meters - 5 to 10 meters - 11 to 20 meters - More than 20 meters

Below you will be prompted to enter the intended installation step of the rafters. By changing this parameter, one can achieve optimal value distributed load on the rafter legs.

Rafter installation step, meters

With the obtained value, we enter the table and determine the cross section of the board for the manufacture of rafters.

Estimated distributed load (kilogram per linear meter of rafter leg)					Cross-section of lumber for the manufacture of rafter legs
75	100	125	150	175	board or beam					round timber
					board (beam) thickness, mm					diameter, mm
					40	50	60	80	100
Planned rafter span between support points, m					board (beam) height, mm
4	3.5	3	2.5	2	160	150	140	130	120
4.5	4	3.5	3	2.5	180	170	160	140	120	120
5	4.5	4	3.5	3	200	190	180	160	140	140
5.5	5	4.5	4	3.5	-	210	200	180	160	160
6	5.5	5	4.5	4	-	-	220	200	180	180
6.5	6	5.5	5	4.5	-	-	-	220	200	200
-	6.5	6	5.5	5	-	-	-	240	220	220

For example, the value given by the calculator is 92 kilograms per linear meter. The nearest upward value in the table is 100 kg, which means we are working with this column.

It is planned to install the rafters so that their span between the support points will reach up to 4.5 meters. We find in the selected column the intersection with this value.

And now you can write out from the right side of the table all the dimensions of the allowable lumber, which is guaranteed to withstand such a load. In this example, this is a 40x200 board; 50×190; 60×180; 80×160; 100 × 140, as well as a log with a diameter of 120 mm.

You can try to change the value of the free span in the planning mode, while still virtually setting additional support points (struts or stocks) to see which material will be more profitable.

On this section of the article, devoted to carrying out independent calculations, we will finish - it's time to move on to considering case study creating a gable roof truss system. But still, a few words in the end.

The algorithms for calculating and designing the truss system are, of course, simplified, and they can be used for not too large-scale construction. If a full-fledged residential mansion is being built, then one cannot do without professional architectural design of both the building itself and the structure of its roof in particular.

An example of installing gable roof rafters - step by step

Work on the roof structure is always quite laborious and complicated, since most of the operations have to be carried out in very uncomfortable conditions at a height. As a rule, it requires the involvement of assistants. But the example below is interesting because the master, using certain technological methods, does all the work completely independently.

To begin with - a project of the future truss system, drawn up after the necessary calculations. It is made using the available SketchUp application, which is easy to find and master even for a beginner.

A house with a semi-attic, that is, the second floor is more than half taken out of gas silicate wall blocks, and only the upper third of the side walls and the ceiling will be replaced by the roof structure. Gables - fully laid out from gas silicate blocks. In the center of the room of the second attic floor there is a capital partition dividing it in two, and this partition is three rows of block masonry above the side walls. This solution allows you to get a roomy attic even with a relatively small steepness of the roof slopes.

And the presence of a central capital partition makes it possible to apply a scheme of layered rafters that is easier to install.

Table - illustrated installation instructions for gable roof rafters

All pictures in the instruction table are clickable, that is, they increase when you click the mouse.

Illustration	Brief description of the operation to be performed
	Timber needed for work has been delivered and unloaded. The first thing to do is to deal with them - put them in neat piles to prevent deformation of the wood, and carry out the necessary processing.
	Processing will consist in applying a special impregnation, which has antiseptic properties- makes wood resistant to biological damage, decomposition and damage by fungus, mold or insects. In addition, many of these compounds increase the resistance of wood to fire.
	Antiseptic primer can be ready to use or in the form of a concentrate. In this example, she required dilution with water in accordance with the attached instructions.
	To improve the quality of processing, it is recommended to thoroughly sweep the surfaces of boards and timber before applying the composition - remove dust and small sawdust.
	Antiseptic impregnation is abundantly applied with a roller, on all sides of the board, for which it is successively turned over during processing. For narrow end sides, it is more convenient to use a brush.
	After processing, the boards are left in a pile until the primer is completely absorbed and dried. At this time, you can start preparing the base for laying the Mauerlat.
	Upper side end gas silicate wall, on which the Mauerlat will be laid and fastened - a board 50 × 200 mm. In order for the board to adhere to the wall with its entire plane, the surface of the base in this case must be slightly trimmed.
	To do this, the master spread construction glue, which was used for laying gas silicate blocks. Then using wide spatula a thin leveling layer was applied.
	A similar operation was performed on the opposite wall ...
	... and then - on the central partition wall, on which the bed will be laid.
	After processing, the boards are completely dry, the leveling layer at the end of the wall is frozen - you can proceed to further actions. First of all, a layer of waterproofing is laid along the end of the wall. In the case under consideration, a polymer-bitumen rolled roofing material cut into a tape is used for this. Laying can be carried out "dry", as in the illustration, or using the appropriate mastic - the quality of the waterproofing will only benefit from this.
	After that, a Mauerlat board cut to the required length is laid on the waterproofing layer. Its width in this case corresponds exactly to the width of the wall - 200 mm.
	The Mauerlat board is carefully aligned along the line of the wall.
	To fix the Mauerlat board to the wall, these anchor bolts will be used, 150 long and 12 mm in diameter. For greater reliability of fastening, thick washers with a diameter of 25 mm are also installed on the anchors.
	So that the installation points of the anchors do not fall into the places of the future installation of the rafter legs, it makes sense to immediately carry out the appropriate markup.
	The installation step of the rafters is calculated in advance, the thickness of the board is also known (50 mm). On the Mauerlat board, the exact locations of the rafter legs are marked - they are marked with two borders with a crossed area between them. And the Mauerlat fasteners can be placed between the rafters. The recommended spacing between anchors is from 600 to 800 mm.
	The process of attaching the Mauerlat begins. To begin with, at the intended points, through holes are drilled in the board with a 12 mm pen drill. Sawdust is immediately swept away so that they do not fall into the drilled channels.
	Then, using a perforator with a 12 mm drill, channels are drilled directly through the holes in the wall for installing anchors. These channels are cleaned as much as possible from the dust formed as a result of drilling.
	Anchors are installed. Each anchor is first carefully hammered into the channel with a hammer until the washer stops against the tree ...
	...and then wraps up socket wrench until complete fixation.
	The installation of the Mauerlat on one wall is completed. A similar series of operations is carried out on the opposite wall.
	Next, you need to install a bed on the central wall-partition. First, as before, a layer of waterproofing material is laid.
	Then boards are laid - the same, 50 × 200 mm. True, the length of the standard board was not enough for the bed, and it had to be laid out from two. In addition, given that in this design of the roofing system, the highest loads fall on the bed exactly in the center, it was decided to make it reinforced, in two layers of boards, that is, with a total thickness of 100 mm.
	But for starters, it spreads and fastens on anchor fastenings the first layer of boards - everything is exactly the same as when installing the Mauerlat on the side walls of the building.
	The bottom board of the bed is fixed, but the protruding parts of the anchoring parts will interfere with the laying of the top layer. This means that in the top board it is necessary to cut out “nests” into which the tops of the anchors will hide.
	In order to make accurate markings for these “nests”, the top board is placed in the place where it should lie, and carefully leveled. Then, at the locations of the anchors, the board is tapped on top with a hammer.
	The protruding part of the anchor will leave a clearly visible mark on the top board, along which drilling will be carried out.
	To drill the nests, a feather drill with a diameter of 25 ÷ 27 mm is used, so that the anchor washer can fit into the hole.
	A through hole is not needed - the depth of this “nest” of 25 ÷ 30 mm is enough.
	The top row of boards is laid on pre-tried places. If everything was done accurately and accurately, the top board will fit perfectly to the bottom one and immediately receive a certain fixation due to the protruding parts of the anchors - you can no longer be afraid of accidental displacement.
	The connection of two tiers of boards to each other is carried out using universal galvanized self-tapping screws 6 × 90 mm. They are screwed in a checkerboard pattern with a step of 250 ÷ 300 mm.
	Everything, the bed is completely ready for further installation work.
	As the next step, the master chose to lay out the block walls of the gables, considering that it would be most convenient for him to do this at this stage. The laying of gables is not included in the plan for considering our publication, and we will skip this step - we will immediately show what happened in the end. Subsequently, the protruding edges of the pediment will be cut off at the level of the roof, the irregularities will be smoothed out.
	As for the rafter system, the next step will be the installation of racks along the bed and the installation of a ridge run. The end posts will be installed first. For the manufacture of racks, the same boards will be used as for the Mauerlat with a bed - 200 × 50 mm. They are immediately cut in the right amount exactly to size.
	The number of racks and their location exactly matches the number and placement of truss pairs. Accurate marking is made on the bed - by analogy with the marking of the Mauerlat.
	The first rack is installed. On it, steel perforated corners (50 × 50 × 2 mm) are already screwed on from both ends with yellow galvanized screws 6 × 40.
	The installed rack is immediately baited through the corner with a self-tapping screw to the bed.
	It is very important to achieve the verticality of these starting posts, while they are not yet completely fixed. Moreover, this check must be carried out in two planes. First, the verticality is checked in the transverse (relative to the axis of the bed) plane - it is set ideally vertically along the construction level.
	In this example, to ensure this position, it was necessary to resort to the use of a small wooden wedge.
	Now you need to achieve verticality in a perpendicular plane. To fix the desired position, it is best to use a temporary brace from a trim board (slat). One end of such a support is attached with a black self-tapping screw to the side edge of the bed.
	Then, according to the building level, the rack is precisely aligned vertically ...
	... and is fixed in this position by a temporary strut using a second self-tapping screw. Now the stand will not move anywhere.
	Exactly the same operation is done with the rack and at the opposite end of the bed. The end posts with temporary supports will become the basis for laying the ridge run board.
	As already noted, for laying and fastening the run on the extreme racks, mounting steel corners were already screwed in advance.
	The board of the ridge run rises up, fits on the exposed extreme racks, and is carefully leveled. The board is used all the same - 200 × 50 mm.
	Then, using a screwdriver, the ridge run is fixed to the corners of the racks. While finally tightening with several screws is not worth it - you may have to make small adjustments. One self-tapping screw on each side (6 × 40 mm) is enough.
	That's it, the ridge run board has taken its place. You can proceed to the installation of intermediate racks.
	Steel corners are screwed onto precisely cut racks, with one ...
	... and then on the other side.
	The rack is set exactly according to the markup, and its edges are aligned with the lying and ridge run. The lower corner is attached to the bed so far with one self-tapping screw.
	Then using building level the vertical position of the rack is verified ...
	... and it is attached through the corner to the ridge run, also with one self-tapping screw.
	So far, it remains so - one self-tapping screw each. The final fixation will be made after the installation of the rafter legs, as it happens that it is necessary to make small adjustments.
	FROM reverse side there is also no corner stand yet - it will be installed necessarily, but later.
	All stands are installed. If everything is done correctly, and the racks are of equal height, then the ridge run takes a horizontal position.
	The next step is the installation of the rafters themselves. But before moving on to it, you need to check and compare the length of the resulting slopes. In theory, it should be equal, but the tree remains a tree, and sometimes small errors run up. It is easy to check - using a tape measure, the distances from the corner of the ridge run to the corner of the Mauerlat are measured. The same is done on the opposite side of the run.
	If a small error occurs, within 25-30 mm, then you can unscrew those same single screws in the right place, make the necessary adjustments, and tighten them again. And in order for this position to remain unchanged during the installation of the rafters, temporary struts from a thin, durable board are installed between the Mauerlat and the ridge run.
	The fastening of these auxiliary temporary elements is carried out using ordinary black self-tapping screws.
	Naturally, the location of temporary supports is chosen so that it does not interfere with the installation of rafter legs. A similar pair of struts is installed at the opposite end of the ridge span.
	Now you can proceed to the installation of rafter legs. It is recommended that during the installation of each next pair, install such a temporary support bar, exactly along the marking line. It will not allow the rafter leg to move during installation, and in addition, a heavy board can be temporarily attached to it with a clamp or the same self-tapping screws so that it does not roll down until the final fixation. The beam is fastened with a pair of black self-tapping screws, and it is easy to dismantle it when needed, rearranging it to the next attachment point.
	The board for the rafter leg rises up and is installed in place, along the lines of the previously applied markings. Its length is usually made 50 ÷ 80 mm longer on each side - for subsequent precise cutting.
	So far, the board rests on the corners of the ridge run and the Mauerlat. It can be temporarily secured from slipping with a clamp to the auxiliary beam.
	Now you need to mark up for inserting the rafter leg into the ridge run and the Mauerlat. It will be most convenient to do so. A well-finished 50 × 50 mm bar is applied along the plane of the run to the rafter leg (as shown in the illustration) ...
	... and a horizontal line is drawn with a pencil along its upper edge.
	Then a square is applied to the end of the run, and a vertical line is drawn, until it intersects with a horizontal one.
	As a result, a triangle was outlined, which will need to be cut out.
	Exactly the same markings were made at the intersection of the rafter leg with the Mauerlat.
	Next, the clamp is removed, the board is removed, and on it hand saw or with an electric jigsaw, cuts are made according to the markup - two triangular fragments are removed.
	The rafter leg is again installed in place, and at the same time it should “like a glove” connect with the ridge run ...
	... and with Mauerlat.
	Further, the second, paired rafter leg is adjusted in the same way. It's time to match them up. At first, the master used the method of simultaneously cutting two rafter legs. One board is installed exactly according to the markup, the second is overlapped on it, and they are tightened together with a clamp. A line is drawn exactly in the center of the ridge run ...
	... and then it is vertically transferred to the rafters with the help of a building level. This line will become the direction of cutting both rafter legs at the same time with a hand saw.
	The cut was made, but it turned out that this approach is not very convenient. It is impossible to use an electric tool for such cutting, and manually, especially in uncomfortable conditions at a height, to cut through two 50-mm boards at once is not an easy task.
	In addition, the mutual overlap of the boards during cutting inevitably gives a small, but still an error. With the next rafter pair, a different approach will be applied.
	But for now, it is necessary to finally fix the rafter legs in place, connect them with the ridge run, Mauerlat and among themselves. For this, metal connecting parts will be used: perforated corners 50 × 50 × 2 for the run, 80 × 60 × 2 for the Mauerlat, and plates 60 × 200 × 2 for mutual bonding.
	With the help of corners and galvanized self-tapping screws 6 × 40 mm, the rafter leg is attached to the Mauerlat ...
	...then to the ridge run.
	After both rafter legs are installed, they are fastened together using a perforated plate and self-tapping screws.
	After installing the first pair of rafter legs, they mount the next one - at the opposite end of the roof. Then, between the extreme rafters, cords are stretched along each slope - above, below and approximately in the middle. These cords will help you navigate when installing the rest, intermediate rafter pairs.
	By the way, as already mentioned, a different approach was applied to the cutting of subsequent rafter pairs. The corner is marked in the same way as before, and then a vertical line is drawn ...
	... which is projected from the center of the ridge run using the building level. After that, the board is removed, and cutting both the corners and the top of the rafter leg along the line is carried out in a position convenient for such an operation, and for this it is quite possible to use an electric manual circular.
	The same operation is carried out with the second rafter leg, and the result is shown in the illustration: everything matched perfectly.
	In the same order, work continues further until the entire “enfilade” of truss pairs is exposed and fixed.
	Now you need to arm yourself with a screwdriver, a good supply of self-tapping screws, perforated corners and plates, and carry out the final fixing of the racks and rafters to the Mauerlat, bed and ridge run. Corners and plates are now installed on both sides of each fastened part, and fixed with the required number of self-tapping screws: for a 50 × 50 corner - at least three on each side, for an 80 ÷ 60 corner - four,
	... and for the plate - five or six for each half. After that, you can remove all previously installed temporary struts - they have already played their role and are no longer needed.
	The next step is to install the bottom row of puffs. These puffs will also serve as the basis for filing the ceiling of the attic room, that is, they must be installed at a certain height - in this case, it is 2500 mm from the floor level of the second floor. To make your task easier, you can prepare a template from the board - the tightening center immediately along it will take the required position in height. The template can be temporarily attached to the rack with a single self-tapping screw, and rearranged as the next puffs are installed.
	The tightening board (150 × 50 mm is used) is installed on a template stand and baited with one self-tapping screw in the center. As you can see, it is still far from horizontal - alignment is required. To do this, the template stand is first dismantled.
	Then, slightly turning the board relative to the self-tapping axis, they achieve its exact horizontality ...
	... and fix this position with one self-tapping screw on any of the rafter legs.
	Puffs with rafter legs will be tightened not only with self-tapping screws, but also with M12 × 120 bolts.
	To drill a bolt hole, use a 12-point drill bit.
	At the intersection of the puff board with the rafter leg, approximately in the center, a through hole is drilled. A bolt with a wide washer is installed in it, the same washer is strung on the other side, then it is baited and finally tightened with a nut wrench. As a result, the junction of the lower puff with the rafter looks like this - a bolt and three self-tapping screws 6 × 90 mm.
	At the intersection of the puff and the central rack, five self-tapping screws will suffice.
	Then lines are drawn - along the outer edge of the rafter legs ...
	... and with the help of a manual circular, the tightening on both sides is cut flush with the plane set by the rafters.
	This sets the entire row of lower puffs.
	For maximum strength of the system being created, and for the final “pinching” of the ridge run, upper puffs are installed from below it. With them, everything is simple. Special alignment according to the construction is not required here - a piece of board (50 × 100) is tightly pressed from below to the ridge run and fixed with self-tapping screws to the rack and both rafter legs, as shown in the illustration. Then, in the same way as with the lower puffs, the edges of the board protruding outward are marked and cut, flush with the plane of the rafters. Such a puff is placed on each rack and rafter pair on one side - this is enough.
	The design turned out to be solid, but in order to exclude even the slightest backlash along the axis of the roof, it makes sense to add a pair of diagonal struts between the first and second racks (truss pairs). Here you can use a board 50 × 100 mm, having previously measured and cut blanks of the required length. For fastening such struts, self-tapping screws are enough. A similar pair is installed on the other side of the roof, between the last and penultimate pillars.
	On this installation of rafters can be considered almost complete.
	True, the outer edges of the rafters that go beyond the perimeter of the house and are necessary to form a neat cornice overhang have not yet been trimmed - as we remember, they were left with a small margin.
	For work in this case, the construction of scaffolding was required. To mark the vertical cutting line, you can make a template bar that sets the width of the cornice overhang from the wall level. Then, a vertical line is drawn along the intended risk with the help of a level.
	For filing the rafter legs from the end, a frontal board 100 mm wide will be used. This means that this distance is laid off from above along the roulette on the intended line.
	Then a horizontal line is drawn through this point using the level. The edge of the rafter is marked.
	Now it is necessary to cut a groove on each rafter into which the strapping board will be laid, which becomes the basis for the further installation of the drip profile. This board should be flush with the surface of the rafter legs. Since a board of 100 × 20 mm will be used, the groove should be the same (counting from the intended edge of the stop).
	After marking all the rafter legs, they are trimmed using a manual electric circular.
	As a result, the edge of each rafter protruding outward takes on this shape.
	You can complete the work with the rafters by installing and securing the strapping and frontal boards.
	Now you can proceed to the stages of flooring waterproofing membrane, the creation of a roofing insulating “pie”, the installation of counter-battens and battens for the selected roofing and other work that completes the creation of a reliable gable roof for the house. All these issues are covered in detail separately on the pages of our portal.

We hope that after studying this detailed step-by-step instruction, readers have answers to many questions facing an inexperienced builder. Of course, this method of installing rafters is just one of many, but it looks simple enough to do it yourself. Well, to expand the amount of information received, we suggest watching a few more videos on this topic.

The construction of a reliable truss system is one of the most challenging tasks when erecting the roof of a country house, cottage or garage. Nevertheless, do not rush to give up - today we will refute the popular belief that such work is beyond the power of a beginner. Knowing the rules of calculation, sawing and installation roof frame, you can build a roof in no time worse than specialists. In turn, we will try not only to talk about the device, design and features of the construction of truss systems various types, but also share the secrets of experienced craftsmen.

Any, even the most seedy roof, is based on a strong power frame, called a truss system. The rigidity of the roof, and hence the ability to withstand even the strongest wind and snow loads, depends on how correctly this structure is mounted.
The truss system is the power frame of the roof, which perceives the entire wind and snow load.

The best material for the manufacture of rafters (trusses) is considered to be a bar or thick board made of softwood. And there is an explanation for this - pine or spruce lumber has a relatively low weight, and the presence of natural resins makes it quite durable. Even if the timber will have a small residual moisture, it will not lead when it dries, which is no less important factor than ease of use and long service life.

Depending on the size of the roof, the supporting structural elements can have a cross section from 50x100 mm to 200x200 mm or more. In addition, the length of the roof directly affects the number of rafters, because they are installed in small steps - from 60 cm to 1.2 m.

Structural elements of the truss system

The main requirement that is put forward to a wooden frame is the ability to resist bending and torsion. For this reason, a triangle shape is best suited for timber frame trusses. However, they can consist of several parts:

rafter legs - the base of the roof frame, which provides greatest influence on the size and geometry of the slopes;
crossbars (puffs) - boards that pull together a pair of rafter legs;
runs - transversely installed bars, due to which the rafters are connected into a single structure;
racks - vertical supports that serve to support the rafter legs or prevent deflection of the runs;
struts - the same racks, only set at an angle to the vertical;
beds - boards attached to the floor of the attic, on which supports are installed;
mauerlat - a support beam installed on the bearing walls, to which the lower parts of the rafter legs are attached;
filly - pieces of timber or boards that are nailed to the lower ends of the trusses and serve to equip roof overhangs.

Additional elements of the truss system make the roof frame more durable, rigid and stable

When choosing the design of the roof frame, it is important to find the very golden mean that will allow you to get a strong and reliable design at minimal cost. For this reason, you can deviate a little from the established canons, if it does not concern the rigidity of the entire structure. For example, it is quite possible to do without fillies, and form a cornice overhang due to longer rafter legs. Or use not a solid Mauerlat, but pieces of timber laid only at the attachment points of the rafter legs - it all depends on the engineering ingenuity and experience of the roofer.

Rafter classification

Depending on the design of the roof and the purpose of the attic, the wooden frame may consist of several types of rafters:

Features and varieties of truss systems

To make an informed choice, you need to understand the features of various types of truss systems and know the strengths and weak sides each design.

Roof frame with hanging rafters

Since the principle of attaching hanging rafters does not imply additional support points, this design is used for buildings with a width of no more than 6 m. Installation of unsupported trusses involves attaching each pair of legs to opposite main walls, while their upper parts are fixed directly to the ridge run.

The roof frame with hanging rafters transfers only vertical forces to the walls, therefore it has simpler attachment points to load-bearing walls

During operation, a force acts on the hanging rafters, tending to push the structure apart. To compensate for the bursting force, a crossbar is installed between the rafter legs. wooden beam or metal profile pipe. If the attic space will be used for domestic purposes, then the upper jumper is attached as close as possible to the ridge, and the lower edges of the pairs of rafter legs are connected with puffs. Such a scheme allows you to increase the useful height of the attic, without reducing the strength of the frame at all. By the way, if the lower jumpers are made from a bar with a section of more than 100x100 mm, then they can also be used as bearing beams. It is necessary to ensure a reliable connection of puffs and rafter legs, since significant bursting forces also act on the place of their fastening.

Roof with rafters

Rafter rafters require the installation of at least one support, so they are used for buildings with internal load-bearing walls. The maximum length of a single span should not exceed 6.5 m, otherwise the strength and rigidity of the roof frame will suffer. To increase the width of the roof, the truss system is reinforced with intermediate supports. Even one additional rack allows you to increase the width of the roof up to 12 m, and two - more than 15 m. The rafter system is ideal when a large roof width is required.

The stability of slope trusses can be increased by using a sub-rafter frame with girders, posts and struts. In addition, this rafter system requires much less lumber costs. Versatility, strength and cost-effectiveness have long been appreciated by both construction companies and individual developers, most often using roof structures with layered beams in their projects.

Combined options

Today, the roofs of country houses amaze with the elegance of design, the quirkiness of shapes and the variety of configurations. There is only one way to build such complex structures - by combining both types of truss systems in one frame.
The combination of layered and hanging trusses allows you to get a truss system of any configuration

Even for the construction of not the most complex sloping roof, both truss systems are used at once. The right-angled triangles located on the sides are layered truss structures. And they are connected due to the upper screed, which at the same time plays the role of a puff for the upper hanging rafters.

The procedure and rules for the installation of roof frames

Since two types of roof frames are used in the construction of roofs, we will consider the installation technology for each structure separately. However, before proceeding with construction work, it is necessary to study the methods of fastening structural elements to each other.

Roof construction with hanging rafters

It has already been mentioned above that hanging rafters are most often used in the construction of small or undemanding buildings. log cabin in this case, it is almost ideal, since you can do without a Mauerlat. The lower part of the rafter legs is attached to the upper crown or the edges of the ceiling beams (matrices) protruding beyond the perimeter of the walls. In the latter case, the puff must be moved up - this will allow you to put the beam on top of the finishing log and make the attic more comfortable.
To increase the height of the attic space, the puff should be installed as close as possible to the top of the roof

Preparatory work

The geometry of the slopes depends on how well the beams will be prepared for the rafter legs. A cord stretched between nails driven into the extreme beams will help to level the supporting surfaces..

It is necessary to cut down the slab, having received flat platforms for the installation of trusses. After that, you should definitely check how accurately they lie in the same plane. This can be done using a long straight rail and a level.
Before installing the trusses, the supporting surfaces are aligned with the cord
After removing excess wood, in each beam you need to make a recess under the rafter spike. You can draw the places of future nests using the same nails and cord as in the previous case. Although the recesses for the rafters can be made both before and after the manufacture of the trusses, experts advise doing them first - this will allow you to try on with higher accuracy and convenience.
The method of attaching the rafters depends on many factors - the type of support beams, their cross section, the features of the roof overhang, etc.
Professional roofers recommend installing an additional reference point in the center of the span of each tong - a vertical rail. One of its sides is used as an axis of symmetry, which will make it possible to monitor the strict observance of the geometry of the structure.
In order to simplify the process of marking and mounting the roof frame, use vertical rails installed along the center line of the roof

Rafter manufacturing

In order for the rafters to have the same dimensions and configuration, they are made according to a pre-made template. For its manufacture, we suggest using the following instructions:

Take two slatted boards and bolt them together to form a drop-down compass design. The threaded connection should not be tightened strongly - the structure should rotate around the top. Be sure to check that the slats are 10-15 cm longer than the rafters - this will be needed to take into account the height of the thrust tooth.
The simplest template allows you to get roof trusses of the same size and configuration
On the rail set as a guide, make two marks. The lower one should correspond to the height of the truss system, and the upper one should be separated from it by the height of the mounting ledge.
Install the template on the mat so that the corners of the boards rest against the recesses for the rafter teeth.
In order for the structure to successfully cope with bursting loads, the thrust tooth at the end of the rafter leg is inserted into a recess on the floor beam
Align the axis of rotation of the "compass" with the upper mark on the rail and set aside the height of the spike from the lower corners of the jig.
Lower the template down and cut the teeth along the drawn line. After that, raise the device to the roof and insert the spikes into the nests on the mother. Check the coincidence of the sample axis with the lower mark on the vertical rail. If necessary, move the bolt to the desired side and fix the angle between the boards with a cross member.
Several methods are used to fasten trusses - it all depends on the type of support beams, the design of the roof frame and the section of its elements
Having adjusted the template in height, apply vertical abutment lines to each board. In conclusion, measure the length of the crossbar and build a template from the scraps of the boards for making overlays on the tops of the trusses.
To attach the crossbar to the rafters, linings from pieces of an inch board are used.

After the template is lowered to the ground, it is disassembled and cuts are made according to the markings. In addition, they construct a separate pattern, along which the ends of the rafter legs will be cut. The manufacture and assembly of hanging rafters is most often done below, raising finished structures to the roof. If the weight and dimensions harvested farms do not allow them to be pulled up manually, then the assembly is carried out on the spot. At the same time, the components of the truss system are fixed with nails ranging in size from 100 to 200 mm.

How to install roof rafters

In order to raise and install farms, you will need the help of at least one person. Fitting and setting the rafters on a plumb line alone is an extremely difficult task - you will have to fasten them to the struts more than once and repeatedly descend from the roof to control the deviation from the vertical plane.
With the help of a rafter tooth, it is possible to obtain such a reliable connection that only one nail can be used for the final fixation.

Raising the assembled rafters up, first mount the extreme structural elements, and then the central and intermediate ones. To strengthen the structure, a support is installed under each leg:

Having set the hanging rafters according to the level, they are fixed with temporary struts. After that, the lower ends of the beams are nailed to the mat or floor beams.
Various temporary structures greatly simplify the process of installing rafters by level.

It is not worth resorting to newfangled methods of fixing with the help of various corners and perforated plates. A reliable "old-fashioned" method of fastening with nails 200 mm long or construction staples will be much better both in terms of strength and reliability, and in terms of cost. At this stage, do not worry about the design looking flimsy.. After the remaining elements of the truss system are installed and the crate is completed, the structure will acquire the necessary rigidity and stability.

Video: making and installing do-it-yourself hanging rafters

Features of the installation of layered rafters

The process of manufacturing and installing layered rafters is generally very similar to the construction of a hanging roof frame. The main difference lies in top point and it is connected with the fact that the tops of the layered beams rest on the ridge run. In this case, the connection with the latter is performed in several ways:

simple adjoining apart (in parallel to each other);
with the implementation of a vertical joint (the same as when connecting the paired legs of a hanging truss);
by tightly fitting the beams to the upper beam (using a vertical cut or notch).

If the design of the wooden frame provides for the support of trusses on the side girder, then the rafters are joined end-to-end, and recesses are made at the junction with the girder.
Nails are used to fasten the rafters, construction staples or overlays made of wood and metal

To ensure the strength of the structure, the cuts should not be too deep.. Experts recommend making recesses no more than a quarter of the thickness of the beam or a third of the width of the board.

Individual developers most often resort to installing rafters in the following way:

the upper part rests on the ridge beam by means of a vertical cut;
from below, the rafter legs are held by a corner cut.

For marking it is convenient to use a construction square. After the scale is selected, on the sides of the right-angled triangle, the values \u200b\u200bof the rise of the slope and half the span are set aside. Thanks to this, it will be possible to obtain the slope angle of the slope without resorting to mathematical calculations.

For the manufacture of rafters, we suggest using the most convenient method:

At first glance, this method is very tricky. However, even a cursory acquaintance with the given instruction is enough to master it perfectly. Of course, it is possible to set aside the necessary distances and make markings by calculation, however, when calculating angles and distances, it will be much easier to get confused.

It should be remembered that the cuts made in the rafter legs must be exactly the same, otherwise the roof slope will be uneven. For this you can use wooden block as a template. It is only important that its thickness does not exceed 1/3 of the thickness of the workpiece.

For the most common slope angles, there are templates that professionals have already worked on calculating the configuration of. Using one of these patterns, you can significantly simplify the task of marking the corners of the cuts.
Templates with marked corners of the cuts allow you to simplify the process of manufacturing rafters

Assembly and installation of a layered structure

Video: installation of rafter legs of a layered roofing system

Methods for connecting rafter logs

When choosing a beam for overall roof trusses, you have to look for a reasonable compromise between the length and thickness of the rafters. The reason for this is the peculiarities of the standard range of lumber, in which longer beams have an increased section. On the other hand, their use is not always justified both technologically and due to an increase in the cost of the structure. The way out of this situation is to lengthen the rafter legs by splicing. The rigidity and mechanical strength timber, so the connection is performed strictly according to a certain method.

Oblique cutting method

The method of merging with an oblique cut consists in the fact that inclined cutouts (cuts) are formed on the mating parts of the bars. They should be carried out very carefully - after combining both parts of the timber, there should be no gaps, otherwise deformation will appear at the junction.
When splicing with an oblique cut, there should be no gaps and gaps between the mating surfaces, which can weaken the rafter and cause its deformation

When making cuts, a small transverse section is left with a height of at least 15% of the thickness of the rafter - the presence of the end part will make the connection more durable. To calculate the optimal length of the oblique cut, it is necessary to multiply the height of the beam at the place of the cut by two. The cut is fastened with nails, clamps or bolted connections.

Coupling

To lengthen the rafter by rallying (stitching), the edges of the boards are overlapped and a rack is installed in the center of the junction zone. The fastening of the elements is carried out with the help of nails, which are hammered according to a certain scheme: Joining the boards by rallying allows you to do without additional overlays, however, it requires the installation of an additional support in the center of the junction area

In order for the beam to successfully cope with operational loads after docking, the length of the rallying section (T) is calculated by the formula T = 0.42 × L, where L is the length of the overlapped span.

frontal stop

The frontal extension connection is that the edges of the individual parts of the rafters are carefully trimmed and matched end-to-end. For fastening, linings made of lumber with a thickness of at least 1/3 of the section of the main beam are used. The length of the overlays is determined by the formula L = 3 × h, where h is the width of the board.
When splicing with a frontal stop, a monolithic structure will be obtained only with the correct placement of fasteners

The fixation of all parts is carried out using a nail fight or bolted connections. In the first case, nails are hammered in two parallel rows, trying to place fasteners in a zigzag pattern. Threaded connection perform in a checkerboard pattern, determining the number of bolts depending on the length of the lining.

Compound length extension

To build up a rafter leg, it is not at all necessary to use both parts of the same section. With a compound build-up, a single element can be lengthened due to two boards that are sewn onto its side planes. The resulting gap is filled with l = 2 × h lumber cuts with a step L = 7 × h, where h, as before, is the thickness of the element being extended.
Composite extension of rafters allows you to attach crossbars, supports and other structural elements in the most convenient way

Tips from experts on the manufacture of rafters and assembly of the roof frame

When starting to independently design and install a truss system, be sure to consult with experienced roofers regarding the features of building roofs in your area. Perhaps their advice will keep you out of trouble and help you save time and money. In turn, we offer several recommendations that will help make the design more reliable and durable:

If a minimum cross-section bar is used to make a Mauerlat or top trim, then cuts can weaken it. For this reason, cutouts should only be made at the lower ends of the rafter legs.
In order to prevent precipitation from falling on the wooden frame and walls of the house, the roof must have an overhang. For its arrangement, pieces of timber (filly) are used, with which the length of the rafter legs is increased, or larger trusses are made.
Connection using cuts at an angle of 90 o cannot be used- in this case, the resistance of the element to load forces is significantly reduced.
If the elements of the truss system are connected by threaded fasteners, then wide washers or metal plates are installed under the heads of the bolts and nuts. Due to the increased area, the fasteners will not be pressed into the wood.
All wooden parts of the structure must be thoroughly impregnated with an antiseptic and fire retardant.
When determining the cross section of the puffs, they are guided by how close they will be to the ridge. The shorter the connecting bar, the greater the load on it and the more powerful lumber and bolted fasteners are used.
When determining the cross section of a beam for the manufacture of rafters, do not forget to take into account the thickness of the heat-insulating layer.

Video: recommendations of experts on the correct connection of the elements of the roof frame

Modern materials and technologies allow you to build a roof of any configuration and purpose. Given this diversity, it is simply impossible to consider in detail all the options within the framework of one article. However, based on the considerations discussed here basic principles construction, you can easily cope with the most complex design. The main thing is to pay attention to the little things, to be attentive and accurate in work. And then the roof will be not only a reliable functional superstructure, but also a real decoration of your home.

The roof is complex and responsible architectural element any building. Its construction should be treated with special attention, it must be remembered that the installation of a truss system requires considerable experience in performing such work and a special tool. You should not take on the creation of a roof for those who hold a carpentry and measuring tool in their hands for the first time - the results of the activity can be very negative.

There are two types of roofs, depending on the number and placement of rafter support points, but each developer can, at his own discretion, slightly change the specific design of the truss system. This takes into account the operating conditions of the building, the purpose of the attic space, the climatic zone of the location, technical specifications lumber and roofing. Of course, the appearance of the truss system is influenced personal experience and developer preferences.

Before proceeding with the manufacture of rafters, you should decide on their type, method of attachment and linear dimensions. Only in this case, you can be sure of the strength and safety of the structure.

How do various factors affect the parameters of the rafters?

physical factor	Brief description of the influence on the parameters of the rafters
	Rafters must withstand snow and wind loads. During the calculations, it is necessary to take the actual maximum values of snow cover from the tables of building codes and rules, take into account the strength and rose of the winds. The data allows you to find out the total load on the roof slope, depending on its area and angle of inclination. Further, it is already possible to determine the dimensions of the rafters, their number and step. In this case, a safety factor is necessarily laid down. The fact is that lumber does not have stable and the same values strength, too many unforeseen factors affect these indicators. For most cases, 50 × 150 mm or 50 × 200 mm boards are used for the manufacture of rafter legs.
	Gable roofs can be layered and hanging. For hanging roofs, you need to make rafters from more durable boards. This takes into account the method of fixing the elements to the Mauerlat. If a cut is made, then the width of the boards should increase by the size of the cut. The fact is that the cut in this place automatically reduces the width of the material that receives the load. If a cross cut 60 mm long is made on a board with a thickness of 200 mm, then only the remaining width of 140 mm is taken into account. Accordingly, if rafters from 200 mm boards are selected when calculating loads, but unforeseen cuts of 60 mm are made during fastening, then the width of the blanks for rafters increases to 260 mm. This remark is made for those who like to abuse various notches and cuts for the thrust areas of the ends of the rafters. There are currently many special devices, allowing you to firmly fix the rafter in the desired position without sawing.
	For residential buildings, rafters must have a safety margin of at least 1.4 of the calculated values. For non-residential structures, the coefficient is reduced to 1.2. Conclusion - the dimensions of the rafters on the houses are larger than on garages and other outbuildings.
	Residential attic space(mansards) must have an insulated roof. The width of the rafters must correspond to the thickness of the insulation layer. At the same time, it is necessary to adjust the step between the rafter legs, depending on the standard width of the insulation. If in this climate zone the optimal thickness of the roof insulation is 200mm, then it is recommended to choose the same width for rafters. Various extensions of narrow rafter legs during roof insulation are not considered the right solution.

This knowledge will help you make the right decisions both during the manufacture of rafters and during their fixation directly in place. Mistakes in the construction of the truss system are too expensive, you should not show excessive self-confidence.

What influences the choicesizes andwaysmountsrafter

A very important point. The task of any fixation is to ensure the stability of the connection node, while it can be fixed or have one or more degrees of freedom. This cannot be achieved without knowledge of the loads affecting the rafter legs. Loads can be permanent and temporary, dynamic and static, unidirectional and multidirectional.

Constant vertical forces. Arise due to the impact of roofing and roof insulation materials. Due to the fact that the rafter legs are located at an angle to the vertical force, they are subject to bending and bursting loads. The magnitude of the forces is determined after the construction of the diagram, on the basis of specific bending and bursting forces, the thickness and width of the boards for the rafters are selected. Fasteners must prevent the spreading of the truss system.
Variable vertical forces. Appear in winter, the value depends on the height of the snow cover.
Lifting wind forces. As a result of gusts of wind, lifting forces act on the roof. They do not affect the dimensions of the rafter legs, efforts are taken into account only when choosing the type of fixation, it must provide for and hold such loads.
Lateral efforts. The value depends on the windage of the roof. As a result of gusts of wind, lateral forces act on the truss system. They increase bending and tearing loads. This feature must also be taken into account during the manufacture and installation of rafter legs.

There are options for rigid fastenings of truss trusses; for this, metal plates, corners, self-tapping screws and nails are used.

Sometimes it is required to use floating rafter connections to compensate for changes in the size of wooden houses. For floating connections, special fasteners and bolts are used. The second allows the rafter legs at the top to turn a little.

Another example of a free rafter connection is a sliding one. Used on log cabins and makes it possible to compensate for the natural shrinkage of the house.

What elements are used to increase the stability and bearing capacity of the rafters

As a result of the correct choice of the truss system and methods of fixing its elements, the structure must be stable, compensate for natural fluctuations in linear parameters and withstand various loads occurring during operation. To fulfill the conditions during fixation of the rafters can be used additional elements fixation.

Runs

Most often they are mounted in the ridge part of the system, the upper ends of the rafter legs rest on them. To increase stability, cuts may be provided. The top connection is rigid or floating on bolts. On large roofs, girders can be installed in the middle of the rafter legs or in other places with critical loads.

vertikaflax racks

They are installed to strengthen the rafters; due to the use of racks, elements can be made from thinner lumber. Vertical racks with their upper end abut against the rafters, and with the lower end against the bed or ceiling beams overlap.

corneraboutpores

Hold bending and expansion forces, universal use. Corner stops can be placed in any places of the rafter leg that cause concerns about strength. Due to such stops, the resistance of the rafters to bending and tearing forces is significantly increased.

Puffs(crossbars)

Purpose - to keep the rafter legs from sprawling, they are used on hanging rafter systems. Most often they are placed in the upper part of the truss; boards with a thickness of about 20–25 mm can be used for manufacturing. The fact is that they work in tension, lumber holds such efforts well. Boards do not work well in compression, quickly bend and lose their original strength indicators.

Knuckleadki

They are used in the upper ridge part of the rafters, due to the use of puffs, the strength of the knot connection increases. Puffs can be made of wood, plywood, OSB or metal.

Bosses(stops)

They have many specific names. They are ordinary pieces of boards 30–40 cm long and 40–50 mm thick, fixed at the bottom of the rafters. They rest against the Mauerlat and do not allow the structure to slip. The use of bosses allows you to perform a rigid connection of elements without sawing the rafters. We talked about the problems that arise in connection with sawing in this article above.

Options for connecting the ridge knot of the rafter legs

The horse is one of the main and most loaded elements of the truss system. The node has several connection options, you should choose a specific one depending on the general parameters of the roof.

With a large length of slopes, it is better not to use a ridge beam, but instead to put two parallel runs and puff crossbars. This design is easier to do, it is more stable and safe.

For a hanging roof, you should choose the most reliable ways to connect the rafter legs, these systems have a minimum number of additional stops.

step by stepWithtruction of the mouthanew rafters

For rafter legs, coniferous boards 50 × 200 mm, first-class lumber, are used. The boards must not have traces of rot or fungus, significant malformations and deep cracks. It is strictly forbidden to use low-quality lumber for the manufacture of the truss system.

To increase the protection of roof elements from decay, it is recommended to use fire protection.

Rafter blanks should be impregnated at least twice, while the material must be dry and clean. Processing is done on a flat area in dry and clear weather.

It can be impregnated with a roller, brush or air gun. It is not recommended to use household hand sprayers - too long and hard. Boards can be lifted up after complete drying of the impregnation.

Our gable roof has a ridge run, vertical supports rest against a bed located on a load-bearing wall in the middle of the building.

Practical advice. If the house is quite high and the boards are heavy, then it is recommended to make an elementary device to protect window openings from damage. To do this, two boards are knocked down in the form of a square, the length and width are selected taking into account the parameters of the opening. The device is installed on the windowsill, and the rafter boards do not damage the foam blocks during lifting.

Preparatory operations

The manufacture of rafters begins with preparatory operations.

Step 1. Raise the rafter boards into the attic. For convenience, place them evenly along the length of the building, put one end on the Mauerlat, and the other on the run bed. First you need to install the extreme rafters on both sides of the roof of the house, pull a thread between them and install and align all the remaining ones along it.

Step 2 Check again the position of the ridge run. It should be located exactly in the middle of the roof. Its displacement by 1–2 centimeters will not affect the strength of the roof as a whole, but it will somewhat complicate the manufacture of rafters and the laying of roofing materials. Besides, experienced builder may notice a mismatch in the size of the slopes and, accordingly, the asymmetry of the roof. It is recommended to achieve a situation so that the ridge run is located along the line of symmetry, if this is not associated with great difficulties. The final decision is made by the foreman on site and depends on the magnitude of the offset and the amount of work to correct the error.

How to straighten a run?

Attach a batten board to the Mauerlat, it is lighter, easier to lift and fix. The second end should lie on the run. The board is nailed to the Mauerlat with an ordinary smooth nail or screwed with a self-tapping screw.
Climb to the top of the run and use a tape measure to check the distance from the edge of the run to the Mauerlats installed on opposite walls. Work very carefully, it is advisable to use insurance. Unfortunately, in practice, few people follow the safety rules, but in vain. Falls from height can cause very serious injury.
Align the purlin to the center and secure the board. To increase rigidity, fix the same board on the other side of the run.

Now everything is ready, you can proceed to the manufacture and installation of rafters.

Installationrafter legs

If you work alone, then you need to fasten a piece of rail to the run at the place where the first rafter is fixed. A rafter board will be temporarily fixed to it to prevent it from slipping down.

And at this time, you can perform work on the manufacture and preparation for connecting the upper part of the rafters.

Step 1. Lift and install the rafter board in place, clamp it to the previously fixed rail with a clamp.

Step 2 Draw lines to cut out the thrust pad. This is done in two stages. First, draw a horizontal line. To do this, press the rail, square or other even object firmly against horizontal surface run.

Second, draw a vertical line. Now the ruler or square should be pressed against the side surface of the run.

Important. The width of the ruler should be no more than 2-3 cm, it is not necessary to make deep cuts and significantly reduce the width of the rafter leg, it loses its maximum design strength.

Make the same markup at the bottom of the rafter. Only now the ruler needs to be pressed against the Mauerlat surfaces.

Step 3 Remove the board and carefully cut out the seats. You can work with a hacksaw or an electric circular hand saw.

Practical advice. If the cuts are made electrically circular saw, then it is better to cut in two steps. First cut to the mark, then turn the board over and cut again to the mark. Knock out the cut piece with a hammer, and remove the remaining protrusion with a chisel or chisel. No need to go behind the line with a saw and try to cut off the ledge in one go. This method increases the cut by 3–5 cm, depending on the diameter of the disk, which significantly reduces the bearing performance of the rafter.

Step 4 Install the prepared rafter in place and check the correctness of its manufacture. Do the same operations with the second leg of the farm.

Step 5 Place the rafters with an emphasis on the Mauerlat and the run, pull them together with a clamp in the upper part. Find the middle of the run and transfer the line to the rafters, use a level or building square (only if the plane of the run is strictly horizontal).

Step 6 Saw through two rafters at the same time along a vertical line. Boards should be tightly clamped with a clamp. Pay maximum attention, the saw blade should be perpendicular to the plane of the rafters. If you cut it obliquely, then the ridge joint will not fit tightly, and this reduces the stability of the truss system and is considered an obvious construction defect.

Docking rafters

With a lack of practical experience in performing such work, the first leg may have a gap in the ridge part, if it is within 1–2 mm, then there is nothing to worry about. If it is more than 4 millimeters, then you need to correct the element. See which planes of the thrust pads do not allow the upper cut to fit tightly. Approximately indicate the amount of additional cut. Remove the rafter and remove the interfering protrusions. Check the connection again, if there are gaps, repeat the operation. As practice shows, experience appears on the second or third rafter and no further corrections need to be made.

Step 8 Secure the rafter legs firmly in place. For this, it is recommended to use metal plates and corners, it is simple and easy to work with them, the strength fully meets the requirements for the truss system.

For each pair of rafters, you will need one large reshaped plate to connect the ridge knot, two 50x50mm corners for fixing to the run and two 60x80mm corners for screwing to the Mauerlat. The thickness of the metal is at least two millimeters.

In the same way, install the extreme rafters on the other side of the house, pull the threads between them. One at the top and bottom and one in the middle. So that they do not interfere during the manufacture of rafters, make a gap between the thread and the plane of about one centimeter.

Real professionals never make one rafter in the attic of a house. Such an algorithm of work significantly increases the construction time, complicates the process itself and makes it unsafe. It is very dangerous to work with electric tools on unsuitable sites, injuries from them are severe, often causing disability.

If the house is delivered with high quality with exact observance of dimensions and rules, then the rafter legs are made according to one template on the ground. Finished items gather on the roof. This technology increases labor productivity by 3-5 times, at the same time the quality of the rafter system is improved, it is more reliable and durable. Of course, the wages of builders also increase proportionally. They work from the development and receive money not for the time spent in the attic, but for the assembled roof.

Video - Manufacturing and installation of rafters on a gable roof

The most responsible and difficult stage is the installation of the truss system. The operation of the roof is associated with constant and periodic loads in the form of snow or gusts of wind.

To figure out how to make a truss system with your own hands, you need to decide on its components. The rafter frame is used for any type of roof, it differs in the level of complexity during installation. Shed and gable roofs are considered simple structures. Hip or hipped roofs provide reliable roof, but difficult to calculate and install rafters.

When choosing the size of the material for the frame, there are many factors to consider. The cross section of the rafters and the supporting base must withstand the weight of the roof, climatic loads, the weight of the devices installed on the roof (if any).

Main elements

The following elements are required for the core of a gable roof:

Mauerlat - a beam of significant size 150 × 150 mm or 200 × 200 mm, which is laid and fixed along the perimeter of the walls. It connects the truss system and the building structure into a common structure, distributes the load exerted on the walls.
The ridge is the highest point on the roof where the rafters join. The longitudinal beam helps to hold the structure, provides stability under wind loads.
Rafters - made of boards with a section of 70 × 150 mm, they bear the entire load. Rafter legs are created from the boards, which are attached in increments of at least 60 cm.
Lying - a beam that is parallel to the ridge. Its dimensions are equal to Mauerlat. The bed is a support for racks and other elements.
Puffs - crossbars from boards connecting the rafter leg.
Racks - bars installed vertically, they are installed to support the ridge run.
Overhangs - parts of the rafters protruding beyond the border of the walls. They allow rainfall to be removed from the house.
Struts - serve to strengthen the rafters, allow you to create durable structures.
Sheathing - boards necessary for tying rafters and laying roofing material.
Filly - when the length of the rafters is not enough for the overhang, fill the additional "filly" boards.

Varieties of truss systems

Several types of truss systems are used to construct a gable roof frame.

Layered - the choice of this design implies the presence of a support in the form of a wall in the center of the building. They receive three points of support and experience only bending load. The upper part of the rafter leg rests on the run, and the lower part on the Mauerlat. This system allows the use of thinner lumber, lower costs and lighter construction.

Hanging - rafter legs rest only on the walls, therefore they experience a large load. To give strength, they are connected by tightening. Such rafters are usually assembled at the bottom and fed straight for installation.

Complex roof shapes require non-standard solutions, for them combinations of hanging and layered rafters are used.

When installing a hipped roof, the diagonal rafters connecting the ridge run and the corners of the building act as the basis for the frame. They are supported by sprigs - short rafters, which, together with ordinary side rafters, form the basis of the roof slope.

Material preparation

The service life of the roof structure depends on the quality of the lumber and its processing. For structural elements, it is necessary to select dry wood, with a moisture level below 22%. It should be smooth and without knots. Before installation, all parts are treated with two layers of antiseptic and flame retardant. When processing, it is worth using a brush, not a spray, then the composition is better absorbed. When choosing lumber, coniferous wood is preferred.

Fastening

The stability of the structure will ensure the competent installation of the truss system with your own hands. To connect the rafters use different kinds fasteners: staples, nails, shaped steel parts - corners and platinum, which are screwed with self-tapping screws.

Rafter section

The dimensions of the timber used for rafters are influenced by:

span size;
the impact of climatic features;
the angle of the slope and the step of attaching the rafter legs.

The permanent load is calculated from total weight roofing material, insulation and waterproofing. With an increase in the distance between the rafters, a larger section of material is required. The coefficient of wind and snow load must be included in the calculation of the cross section. Common rafter sizes are 50x150mm and 60x200mm.

Rafter length

The base of a symmetrical gable roof is an isosceles triangle. Knowing the height of the ridge, you can calculate the length of the rafter using the Pythagorean theorem. In this case, it is the hypotenuse, and half the width of the lady and the height of the roof are the legs.

Rafter installation

The first step in the installation of the truss system for any type of roof is the laying and fastening of the Mauerlat. Under it, waterproofing in the form of roofing material is necessarily laid. This beam requires drilling holes along the length, into which the studs embedded in the masonry are inserted and tightened with a nut.

Having created the basis for the frame, a template is made according to which all the rafter legs for the hanging system are assembled on the ground. To create a sample, take two thin boards equal in length to the rafter and fasten at the ends with a nail. This workpiece is set to the width of the run, and the resulting angle is fixed by pieces of the board.

A second template is used to mark the mounting cuts at the top and bottom of the rafters. Its basis is plywood. When assembling the legs, you need to strictly follow the template so that you do not have to redo the design. The upper part of the rafters is connected by a wooden or metal plate.

If collected roof trusses have significant weight, you will have to use equipment or devices for lifting.

The first pair of rafters is installed on opposite gables. It is fixed with temporary struts and set according to the level. A cord is stretched between the legs, as a guideline for installing the remaining roof trusses. The structure is connected by crossbars, struts and supports.

With a small span, the rafters are not fastened with a ridge run. A roof with a width of more than five meters requires strengthening the structure with a ridge beam. This beam is attached both under the rafters and above them. The connection occurs with a gash and plates. With a large length of rafters, support posts are installed that protect against sagging.

The completion of the installation of the truss system will be the fastening of the crate.

To know how to properly perform the truss structure, you can watch a video that tells about the stages of work.

Video

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Installing rafters: 2 simple instructions for self-fulfillment

Planning to build a roof frame, but don't know where to start? I will tell you how the installation of rafters is carried out on houses made of gas silicate blocks and on frame-type buildings. As a result, you will be able to choose the right simple instructions and apply it in the construction of your country house.

Installation of rafters on a brick house

As an example, consider how to independently install a truss system on a gable roof for a suburban brick house. The peculiarity of this roof is that in the attic you can arrange an attic with your own hands.

The facade walls turn into pediments made of the same wall material. This fact will simplify the task, since the roof frame will be built between the gables. In addition, a roof built between brick gables is more stable in terms of wind load.

The peculiarity of this roof frame is that it will be built without timber, but only from boards. The problem of the absence of a beam will be solved by a longitudinal connection of two boards, for example, this will be done when laying down. This approach is due to saving money, since two 200 × 50 mm beams will cost less than a 200 × 100 mm timber.

Construction technology

Illustration	Step-by-step instruction
	Preparation of materials. To assemble the truss system, we will use a board 200 × 50 mm. In addition, you will need fasteners and waterproofing materials. Before work, we impregnate lumber with an antiseptic and dry it.
	Mauerlat installation. In accordance with the previously proposed drawings, we put the power plates on the side load-bearing walls. Before installing beams, over brickwork we lay out a bituminous substrate. We fasten Mauerlat to the wall anchor bolts with a diameter of at least 12 mm. We select a bolt installation step of at least 1.5 m.
	Installation of the bed. Laying the bed on the intermediate wall is carried out according to the same principle as the installation of Mauerlats. The difference is that we lay the bed in two boards, since the distribution of loads on it will be greater than on the outer walls.
	Installation of the ridge run. On the bed, close to the gables, we fasten the extreme vertical racks. So that the racks do not move during installation, we temporarily fix them with diagonal struts. On top of the racks, with the help of perforated metal corners, we fasten a horizontal beam - a ridge run, on which the tops of the rafter legs converge. Following the example of the extreme racks, in the interval between the run and the bed, we install intermediate additional supports in increments of 80 cm.
	Fitting the first rafter. We apply a board installed on the edge to the run and the Mauerlat. On the board at the level of the run and at the level of the Mauerlat, we draw the edges of the notch with one horizontal and one vertical side. As a result, the edge of the overhang of the beam below the Mauerlat should be at least 60 cm. Cut out the corners according to the markings.
	Rafter fit. Following the example of one blank, identical cuts are made on another board. Then the beams are installed on the run and seized with a clamp. By level, we mark strictly vertical center line, along which we cut the combined boards. The result should be a skate, as shown in the photo.
	Rafter fastening. We fasten the beams combined on the run with perforated metal corners in the lower and upper parts. In addition, the ridge knot is additionally tightened using a perforated metal plate. All fastenings are carried out on self-tapping screws. For greater reliability, we use colored self-tapping screws, as they are galvanized. Black self-tapping screws are only suitable for temporary installation.
	Rafter installation. On the contrary, the already assembled truss truss, we install the last truss. Between established structures we pull the cords, one at the level of the ridge, the other in the middle and one more closer to the Mauerlat. We install and align the intermediate rafters along the cords.
	Installing puffs. To strengthen the truss trusses at the level of the bed, we fasten horizontal struts, which must go through the edge of the opposite rafters on both sides. We make a puff from a board placed on the edge. We fasten the board to the rack with self-tapping screws, and to the diagonal beams with self-tapping screws and a bolt with a nut through cap washers. We install similar puffs at the bottom of each farm. We cut the side ends of the puffs flush with the surface of the rafters. Subsequently, the installed puffs will be used as floor beams.
	Trimming overhangs. We mark each overhang so that there is a recess for fastening the eaves board and a vertical cut for installing a wind board. You can take measurements on each board separately, or you can make one template and go around all the overhangs with it and evenly transfer the markup According to the markings made, we cut off all the overhangs with a miter saw.

Installation of rafters on a frame house

I offer another example, where the installation of the truss system will be carried out on a 6 × 6 frame house. At the heart of the house, a wooden lattice frame was used for subsequent filling with insulation and sheathing with slab materials.

Since the construction will be carried out on a frame house, the requirement for rafters, as well as for the selection of roofing material, is one - this is a small weight without compromising the strength of the structure. Therefore, during construction, it will be correct to use a dry board 200 × 50 from coniferous wood.

Assembly technology

Illustrations	Description of the main stages
	Installation of floor beams. Across the upper trim of the walls, boards laid on the edge are installed - logs. The optimal installation step, which ensures high strength in combination with an acceptable floor weight, is 35-40 cm. The laid floor beams in the frame house structure will be the base of the trusses.
	Rack mounting. The rack is assembled from two boards folded flat. One board is 2.4 m long, and the other is shorter - 2.2 m. The protrusion resulting from the difference in length will be used as a stop for the run. We install the rack according to the level and support the struts during the installation of the entire structure. The dimensions of the stand are approximate, and you can adjust them, taking into account the selected angle of inclination of the slopes.
	Installation of the remaining racks and run. Following the example of the first rack, an extreme rack is installed. The run is attached so that the horizontal beam lies on the steps. The run-out on the extreme racks is provided for the subsequent sheathing of the pediment. Intermediate supports are installed between the extreme racks.
	Mounting the junction of the rafters to the beams. One end of the rafters is laid on the run, while the other end is laid on the bottom trim. The edge of the rafter is fastened with nails directly into the floor beam. Thus, we carry out the installation of two extreme boards, we stretch a cord between them and install intermediate beams along the cord.
	Mounting the ridge knot. We join the upper edges of the rafters according to the preliminary gash end to end. On the inside of the node, the junction of the rafters is attached wooden lining as shown in the photo. The trims can be cut from scraps that you will have left when assembling the uprights. The overlay and the ridge knot are connected with nails, plus a metal mounting bracket fixed on self-tapping screws is installed at the junction of the overlay to the run.

Summing up

Now you know how to properly install rafters for roofs with two slopes. If you still have questions about the proposed instructions, you can ask them in the comments to this article.

December 12, 2017

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