The truss frame sets the geometric and operating parameters pitched roof. Due to violations in the installation technology, due to flaws in the manufacture of its elements, distortions of the system, traditional leaks, holes in the coating appear, threatening emergency situations.

In order to build a reliable and stable roof structure, you need to clearly know how the sawing and installation of rafters is performed, followed by fixation to the supporting elements.

Rafters, or rafter legs, are wooden or metal beams installed on the house box at a given angle. They determine the configuration of the roof structure, take on and steadfastly resist the sum of permanent and temporary loads acting on the upper enclosing system of the building.

The structural simplicity of the rafter legs is extremely deceptive. Actually it's quite complex elements requiring careful marking and accurate cutting. Inconsistencies in the connections of the rafter legs with the Mauerlat, with each other and other components of the system lead to a change in the shape of the slopes, a violation of the integrity of the coating and the destruction of nodes.

On the other hand, competent installation rafter legs can correct some errors in the construction of the box at home, and not aggravate the situation by a clear repetition and intensification of wall height differences. True, in such situations, the frame elements are made individually and scrupulously adjusted in fact directly at the facility.

However, before dealing with the specifics of installation, you need to find out what their design differences are, according to which the rafter legs are divided into two groups, these are:

• Hanging. Type of rafters that do not have an upper support. At the top of the roof, the rafter legs rest against each other with their ends. To under the weight of the components roofing cake and snow, such a design did not burst the Mauerlat beam, the hanging rafters are connected with a horizontally installed puff.
• Layered. A kind of rafter legs, stacked on two supports of different heights. At the top, they most often rely on a ridge run installed in the cross to the rafters, less often they rest against each other, cut down at an angle. The bottom rests on the Mauerlat beam or rests against it.

The scope of their application and installation technology depend on which group the rafter legs belong to. The hanging variety is collected on the ground, and the trusses, made in the form of peculiar triangles, are raised to the roof and mounted in a form completely prepared for installation.

The advantage of building a truss frame using hanging technology lies in the safety of work and the ability to perform nodal connections as accurately as possible. If the simplest version of a hanging truss with a puff at the bottom is used in the construction of the roof, you can abandon the Mauerlat device, in place of which a narrow leveling board is quite suitable.

The disadvantages of hanging technology are accompanied by advantages. For example, a truss assembled on the ground is much more difficult to transport to the installation site than boards and timber for layered rafters. There are restrictions on the spans to be covered: the limit is 14 m, above which it is unreasonable to install wooden beams prone to sagging without intermediate supports.

The rafter legs of the layered group both top and bottom are based on independent structures. The top of them is laid on a purlin structure, which is mounted on the floor beams or on the bed, replacing the Mauerlat on the inner wall. The bottom is either installed on the Mauerlat, or rests against it, catching on the bar with a tooth or a support bar sewn instead of a tooth.

The advantage of layered systems is rightfully recognized as the possibility of overlapping almost any span in size. It’s just that with an increase in the overlapped space, the design becomes more complicated: it is supplemented with struts for a couple with racks, additional runs, coupled with beds, fights.

The layered structure is assembled and mounted longer, because. it is built not from farms, but from individual elements. However, just this scheme has more opportunities to correct the shortcomings of a box or an unevenly settled log house. Because layered rafters are stacked individually, it is possible to slightly change the position and size of the node, in order to eventually form a perfectly aligned slope plane.

The specifics of the manufacture and installation of rafters

It is clear that for the construction of the truss system, lumber will be needed - long-length products of timber processing enterprises with clear geometric parameters. You will need a board or timber, on which, of course, there are no mounting cuts and cuts for installation.

Why are cuts and cuts needed? The fact is that when placed on an edge, boards and beams have too little support area. They are in contact with the Mauerlat with only one vestma in a thin line, because of which, at the slightest load from above, they can tritely “move out” from their position and drag the entire structure with them.

In order to increase the area of ​​\u200b\u200bsupport in the junction of the rafter and the Mauerlat, or it and the additional run, a corner cut is selected in the beam or board, a tooth is cut out or a support bar is sewn on. If the top of the rafter is paired with a mirror-opposite counterpart, then for a reliable stop, you will need a gash, the plane of which must be clearly perpendicular to the horizon.

The basic rule in the construction of truss frames is that the support sites selected in the lumber are strictly horizontal and vertical. At the slightest violation of horizontality with verticality, stability is lost, structural parts are displaced under their own weight and load, up to the complete destruction of the system.

Note that the nodes of the truss systems are entrusted with the obligation to ensure the possibility of a slight displacement and rotation when the load is exceeded. These movements are necessary in order for the structure to bend slightly, move slightly, but not collapse and remain stable.

These subtleties should be known both to the master who decided to do the manufacture and installation of rafters with his own hands, and to the owner of the house under construction, who does not want to pay for the poor-quality labor efforts of the builders' team. Let's analyze the common options to understand the essence of the process.

Hanging roof frame construction

Consider an example of the construction of a truss system over a log cabin of a bath. The span between the walls is small, it is easier and more reasonable to block it with a hanging structure, the installation of which will be carried out on the bypasses of the ceiling beams - matrices.

The log base is an almost ideal option for installing hanging systems, because. it is easiest to cut it into the horizon, eliminating the need to adjust the rafters in case of a violation of the geometry of the foot. There is no need for a Mauerlat device. However, the puff will have to be moved up in order to bypass the upper crown of the log house and form a useful attic space.

Before performing the installation of the rafters, a phased preparation of the log house is carried out. On both sides of the foot, we align the bypasses according to the lace tied to the nails hammered into the two extreme beams. On top of the bypasses, we cut off the slab so that the edge of each beam ends with a flat horizontal platform.

The surface formed after squeezing the upper bulge of the log along the edges of the beams is aligned to the horizon according to the level. We apply the specified control tool to three or more beams at the same time. If the level is not long enough to carry out such a check, use a long rail or board instead.

After squeezing all the excess, we mark the nests for the rafter tooth. To do this, we again use nails and lace. Note that it is possible to draw nest sampling sites on the bypasses both before the construction of hanging trusses and after. However, it is much more convenient to make nests before making rafters. They will help to carry out the fitting with higher accuracy.

To facilitate your work, it is advisable to find the center of the log house from the side of future tongs. At these points, it is recommended to nail along the control rail, one of the edges of which will indicate the axis of symmetry. You can do without rails if you already have some experience in the construction of roofs.

• We sew two inch boards 10–15 cm longer than the designed length of the rafters at the top with a nail or bolt so that they can rotate around this connecting point.
• On the rail installed in the center of the future tongs, we mark the design height of the truss system. We put one more mark above it - this is the height of the tooth, more precisely, the length of the vertical laid off from the base of the tooth to its top.
• We set the boards sewn at one point to the extreme bypasses so that the corner of each board rests against the future socket under the tooth.
• We combine the connection point of the boards with the upper mark on the rail, which determines the length of the rafters with the tooth.
• From the lower corner of both rafters, we set aside the height of the tooth, return with the template blank to the ground and cut out the tooth according to the markup.
• We return the template blank to its place, install it by inserting the teeth into the sockets intended for them. It may happen that after installation, the top of the workpiece does not match the directions of the rail. Then you need to pull out the nail and adjust the position of the top, be sure to mark a new point.
• After fitting the top, we draw a vertical line of their upcoming joint on both boards, measure the size of the crossbar and mark on the trimmings of the board the shape of the overlays for the upper joint of the rafters.

If everything turned out exactly and no more adjustments are required, the template is ready. We return with him to the ground. We disassemble the workpiece and make cuts along the marked lines. The parts obtained as a result of fitting and fitting will serve as a standard for the practically in-line production of roof trusses in the required quantity.

We will assemble hanging farms on the ground. Their installation, as well as fitting, should be carried out by at least two people. One master simply can not cope with such work. The performer at the top will install the truss, and the second one will change its position according to the plumb line. The position of each leveled and installed truss should be fixed with temporary struts.

To increase the stability of the system, we will install racks under the rafters:

• Let's mark the matrices under the place of installation of additional supports in an already proven way: we will hammer in a nail from opposite sides and pull the cord.
• We will hollow out nests in the logs according to the markings.
• Let's try a piece of a bar to the installation site. We mark on it the line washed down, taking into account the height of the spike.
• We will make a rack and two linings for attaching it to the rafter.
• Install the support made and fix the position of the truss truss on the other side in the same way. According to the verified scheme, we continue to work until we equip each rafter with an additional support.

To ensure the rigidity of the hanging system roof trusses connected by wind ties - boards, poles or slats nailed from the inside of the structure. FROM outside rafter frame rigidity will increase due to the construction of the crate.

The rafter legs are attached to the matrices with 200 mm nails or angle brackets. In this regard, metal corners and plates with perforation for fasteners significantly lose traditional methods. To the sidewalls of the rafters we nail fillies made of a board, the width of which is half less material used in the manufacture of rafters.

The length of the filly should be 70 - 80 cm more than the designed width of the overhang. This distance is necessary for their reliable connection with the rafter legs. The fillies can be cut in advance, or without preliminary cuts, you can nail the trimmings of a narrow board to the rafters, and then draw up the line of the eaves. However, the first option is more convenient and economical.

In most cases, as in the example above, fillies must be partially buried in the mats bypass, for this:

• We note in fact the width of the filly at the bypass.
• We make two cuts with a saw according to the markup for 2/3 of the thickness of the filly. We also saw the log between the extreme cuts with a saw. We refine the recess with a chisel, accompanied by a hammer.
• We install the fillies in the formed recesses, sew them with rafters with nails 100 mm long.

Upon completion of the installation of all fillies in the last ones, we hammer in a nail. We pull the control cord and mark where to saw off the excess.

The device of the layered roof frame

In the construction of a truss frame using layered technology, there is much in common with the installation of a hanging structure. The fitting is carried out in almost the same sequence, so it makes no sense to describe the actions twice. The main difference is in the methods of forming the upper node, because the tops of the layered rafters have a support - a ridge run.

If at the top the layered rafters are tritely based on a ridge run, they are laid either with a run, i.e. parallel to each other, or with a strictly vertical joint, similar to the docking of hanging legs. However, in most cases upper part they try to fix it with a notch or a vertical cut with a tight fit to the ridge beam.

There are schemes according to which the layered rafters are based not on the ridge, but on the side run. In such situations, the top is formed according to the hanging principle, and the point of support on the girder is made out with a corner cut.

Let us analyze the most popular option in private construction for the construction of rafter legs with support on the lower corner cut and on the ridge run through a vertical gash. Note that the maximum depth of the cut should not exceed 1/3 of the width of the board.

Option for marking with a construction square:

• On the square, we mark the height of the roof and half the span on a scale. These values ​​reflect the slope of the slopes and set the main angles. The proportions must be exactly maintained.
• If further use of the square is not planned, then the delayed points can be marked with screwed bosses or short screws with screws, if planned, then better paint which is removed by the solvent.
• We apply a square to the board laid flat with the side on which the height of the roof is marked. We draw a line according to the indications of the square - this is the line of the upper cut of the rafter - the section of its interface with the ridge run.
• Cut along the marked line with a circular saw. Lay the board for sawing flat, as it should be when cutting in width. Longitudinal cuts are made with setting on the edge.
• From the top of the formed angle, we set aside the length of the so-called diagonal. This is the distance from the junction point with the run to the outer edge of the Mauerlat or the upper trim, if a frame house is being equipped.
• We move the square to this point. We draw a line parallel to the first.
• We turn the square over, move it along the workpiece so that 2/3 of the total distance is on the left, and 1/3 on the right. In the picture, these are 8ʺ and 4ʺ.
• The line of a smaller segment will just designate a cut for us.

At the end, we draw an outline on the board eaves overhang, cut it along the outlined lines and use a do-it-yourself rafter blank for sawing the rest of the roof elements.

You can apply the described method without a building square and marking the parameters of the roof on it. Enough to imagine the process to postpone necessary distances conventional drawing tool. However, without experience, you can get confused in the calculations of angles and segments.

To help novice builders, a template has been developed with options for forming corner cuts. It will help you navigate the manufacture of rafter legs from the most common lumber in this area.

In cases of laying rafter legs with notches in the upper and lower parts, it should be remembered that the depth of both notches must be the same so that the roof slope does not change during construction work. Usually, for the device of two equal cuts, an auxiliary bar is used, the thickness of which is not more than 1/3 of the thickness of the board.

The rafter blank is then installed with an edge on the Mauerlat and on the run. The bar is applied on the side in the area of ​​​​the lower and upper nodes to outline the cut.

If the cut is needed only in the lower part of the rafter, and the top will be based on the run with a cut, the board is installed at the bottom on the Mauerlat, and at the top on the run and the bar, so that as a result of cutting, the slope of the slope does not change. At the bottom, a second bar of the same size is applied to the future node and the outline of the future cutting is outlined with it.

The same methods are used to form cuts with a tooth. The difference is only in the form washed down.

The installation of layered rafters begins with the installation of two extreme trusses. The elements are mounted one at a time, their position is carefully checked using a plumb line. Most often, extreme farms are arranged from paired boards, because. they carry more load. They are fixed with temporary spacers, then connected with a cord or rail to indicate the plane of the slope.

Ordinary rafters located between the extreme load-bearing trusses are installed according to the instructions of the laces. If necessary, correct the position of the legs according to the actual situation.

Video about installing rafter legs

Installation of rafters with fastening with metal corners:

How to make rafter legs with cuts for landing on a Mauerlat:

The device of the truss frame under the roof of the garage:

We have given and described only a part of the methods for constructing truss frames. In reality, there are much more manufacturing and installation methods. However, an analysis of the basic options allows you to perfectly understand how to properly make rafters and truss trusses for the roof, how to saw them down before installation.

Is it time to install the roof? The very first thing you need to do is the installation of the truss system. This work is very important and difficult, and therefore it is necessary to carefully read our advice.

A bit of theory - what you need to know about the truss system?

First of all, you need to talk about the types of truss systems and their characteristics. So, this system consists of the following elements:

• rafter legs;
• racks and vertical supports;
• struts;
• puffs - an element that connects the rafter legs.

You should also distinguish between rafters by type. Rafter systems are divided into:

• Layered. They should be used if the building has internal partitions or other supports. In this case, the "legs" of the structure must rest on both the outer walls and the inner ones.
• Hanging - in which the "legs" of the structure rest only on the outer walls. Distinctive feature of such a design is that for its design it is necessary to tighten due to high expansion loads.

Several important technical characteristics

When choosing a method for installing rafters, it is necessary to evaluate the complexity of the work and the weight future design. If the assembled product will be light in weight or you can bring special lifting equipment to the site, then it is best to assemble the rafters on the ground, and then lift them to the roof of the building, where you can do all the other work. If the structure is characterized by a large weight, then it will have to be assembled directly on the roof - this is easier and safer.

It is very important to correctly connect the upper parts of the rafters. This work can be done in several ways. First of all, end-to-end, when cuts are made at the required angle on opposite rafter legs. Next, the rafters need to be docked along the ends obtained and secured to several nails. For a more secure connection, secure the products with a metal strap.

It is possible to fasten the rafter legs with an overlap - in this case, the structural elements are in contact with each other by planes. If you are going to make a rafter system in a house with fronts that are made of logs, then the rafters must be placed on the walls using the sliding fastener method. Thanks to this, you will be able to avoid deformation of the roof in case of shrinkage of the house.

If you decide to use this method, then you need to consider that it is quite difficult to do it yourself. Fasteners are made as follows: the "legs" of the rafters must be placed with a gap, fastening them together using a specialized movable metal element. Now we proceed to the direct construction of the truss system with our own hands.

Mauerlat - what is it and why?

The construction of the rafter system must begin with the installation of a Mauerlat - these are the foundations for the future design. Mauerlat is a log or timber, which is attached around the entire perimeter external walls. Undoubtedly, it is possible to make a structure without a Mauerlat, but it will be quite difficult and even risky to build such a structure with your own hands. It is very important to follow all the recommendations exactly so that the base for the truss system performs its functions 100%.

Important Tips:

• Before laying the mauerlat, the walls must be insulated with a suitable waterproof material. To save money, you can put several layers of roofing material.
• Installation of logs is carried out on a reinforced belt with a small indent from the edges of the walls.
• It is best to choose logs of antiseptic wood with a section of 10 * 15 cm.

For the convenience of doing work with your own hands, the bars must first be laid out from one front to the other along the entire length of the wall. After that, you can take measurements: lay out the bars according to the level, watching the evenness of the distance between them. Next, you can attach the bars to the walls. As we have already said, it is preferable to carry out installation on a reinforced belt, using anchor bolts as a fastening product - it is better to fasten them when pouring a reinforced belt. Also do not forget to drill holes in the beam itself.

Important: if you want to achieve a perfectly even position of the bolts, before pouring the “belt”, attach the board to the bolts and attach the fasteners vertical position using a square.

We put the base prepared with our own hands on stands consisting of planks, after which we carefully lower the bars onto the bolts, each time taking out a plank. At the end, we wind the washer to the bolt. Now it's time to learn how to make a truss system with your own hands.

Do-it-yourself installation of a truss system

We have already talked about the installation of the Mauerlat. Now it's time to move on to the main point of installing the truss system - this is the installation of floor beams and a ridge beam. But first things first. Floor beams - beams with a section of 20 * 10 or 15 * 10 cm. The length of the products should be such that, when laid on the walls, the beams form an extension that will correspond to the width of the eaves.

If to speak in simple words, the bars should go beyond the walls at a certain distance. The bars are installed in one direction, leaving an equal distance between them.

To ensure that there are no errors during the execution of work, a clear sequence of actions should be followed:

• We mount the boards with our own hands, retreating from the edge of the walls by an average of half a meter.
• We stretch the cord between the bars - it will serve as a kind of "beacon" for the installation of the following beams.
• The distance between the "legs" of the structure must be chosen based on the section of the rafters. So, if you decide to choose "floor" boards, 5 * 15 cm in size, then the step should be about 60 cm. It is worth noting that this will greatly simplify everything further work. And all due to the fact that the width is most often 60 cm, which means that nothing will need to be trimmed.
• We proceed to the installation of transverse bars, which in one part should be in contact with the extreme beam, and the second - go beyond the walls. The gap between such jumpers should be about 1 m.
• We attract the beams to the base (Mauerlat) with the help of nails, you can also use self-tapping screws and steel corners (for reliability).

To make it as convenient as possible for you to carry out work during the construction of the truss system with your own hands, lay ordinary boards on the beams.

Now it's time to talk about installing a ridge beam. This stage consists of several steps:

• Installation of auxiliary racks, which are U-shaped struts made of wood. Professional experts advise that the height of the spacers be equal to the height of the first floor.
• We assemble racks at opposite ends of the structure and put intermediate beams, maintaining a step of 2.5 meters.
• After mounting the racks, we lay the ridge beam on top ( wooden plank with a section of 5 * 20 cm). Fix the structure with self-tapping screws.

Since the rafters must have the same length, it is advisable to make a template in advance to determine the length. To do this, we take one board measuring 2.5 * 15 cm, apply it to the beam and to the ridge, and put marks at the points of contact and saw off the unnecessary part - you can make blanks using this template. True, it is worth noting that not everyone can achieve perfect evenness, and therefore get ready for the fact that during the installation process you will have to use the saw more than once.

If you neglect this advice, then the skate may bend, which may make the design not so reliable.

After you have installed the truss system, you need to make waterproofing, create a crate and cover the structure with roofing material. Now you know how to assemble the truss system - the roof is almost ready. We hope our tips will help even you to do the work yourself.

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Installing rafters: 2 simple instructions for doing it yourself

Construction planned 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 can choose a suitable simple instruction and apply it when building 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 beam.

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 bearing walls. Before installing the beams, we lay a bituminous substrate on top of the brickwork. We fasten the Mauerlat to the wall with 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 a 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. Besides, ridge knot additionally tighten 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 frame house 6×6. 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 roofing material one is light weight without sacrificing structural strength. Therefore, during construction, it will be correct to use a dry board 200 × 50 made of wood conifers.

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 weight of the floor is 35-40 cm. The laid floor beams in the structure of the frame house 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. FROM inside 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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building own house is always a waste: starting from the project and ending with its implementation, you cannot do anywhere without the help of professionals. But is it really so? Isn't it possible to do most of the work with your own hands? You can, if you use the tips from our site!

There is a lot on the resource, how about a reliable foundation for any building. But, in addition to a stable foundation, the coziness and comfort of staying in the house is affected by that which does not leak and helps to keep the heat in the room.

Any roof structure cannot do without high-strength rafters, and their assembly is one of the most time-consuming tasks in the construction of a monolithic or private house. Frame for new roof you can buy at the nearest woodworking sawmill, and you can install it yourself, observing all the technological requirements and features of different configurations. Next, consider the main elements and methods for installing rafters on the roof of a private house.

Roof structure elements

Mauerlat- the main component of the entire system, a kind of foundation, which is installed along the perimeter of the walls and creates an optimal load balance, protecting the structure from involuntary movement at the time of strong winds or heavy rainfall. Mauerlat can be made from planed timber, in some houses it can be replaced by the upper wall trim.

rafter legs- designed to hold a kind of sandwich. A sheet of sealant is laid between the supporting rafters, and a crate is placed on top of it.

Runs- solid beams that are laid in level along the roof. Used to fix rafter legs. They are divided into several types: ridge run (located in the upper part of the roof), lateral (located in the center of the supporting legs of the rafters).

Racks- take on a small weight of the structure. They are used to strengthen the stops of the rafters and the ridge.

Struts- are installed specifically to hold the rafter legs. Mounted in an inclined position. Gives the building extra strength.

Installation of the truss system

To get started installation work for the construction of the roof of a private house, it is advisable to familiarize yourself with the theoretical part, from which you can learn how to properly install the rafters on brick or wooden walls. Consider the most common sequence for installing the elements of the truss system.

Mauerlat installation

Before laying the mauerlat on wooden walls, you can add one log at a time around the entire perimeter to increase the height of the ceiling. Under the upper logs, which will be the base, it is advisable to put a knitting wire, with which it will be attached to the base of the wall. An easier way is to secure the base with large anchor bolts.

First comes a waterproofing film or roofing material. Next, lay out the finished workpiece around the entire perimeter of the walls. In some cases, the length of the bars may be fewer walls in this case, they must be equalized.

How to connect mauerlat

After installation, we check the geometry. For this operation, a laser level is ideal.

This operation should not be neglected - the slightest inaccuracy of 1-2 cm threatens with poor-quality assembly of the entire truss system, which can lead to unplanned roof repairs as early as next year.

Good to know. by the most in a simple way check is considered a rope or fishing line. With their help, you can measure the distance of one diagonal (from one corner to the opposite), fix and compare with another, and if the result matches, then everything is done correctly.

We fix the corners of the Mauerlat.

We fix the entire structure with wire, anchor bolts or studs. For fastening with studs and anchors, holes must be made in advance. A low-speed electric drill can easily handle this. Screwing the bolts is best done in several stages, alternately on each side.

We make the correct installation of rafters

rafters

Before proceeding with the installation of rafters, it is advisable to decide on the type, there are only two of them - a hanging installation of roof rafters and an inclined one. Their main task is to fasten and hold all the elements, and the difference is the number of supports.

Inclined have 2 or 3 pcs. For small buildings with small spans, an inclined rafter installation system is used. Gable are used for domestic or public premises, which are endowed with additional, load-bearing partitions and columns.

In the area of ​​\u200b\u200bthe base of the beam, the rafter legs should fit snugly against the Mauerlat, and at the top - into the ridge run, which is mounted on racks mounted on the lower run. The connection is best made on pre-prepared cuts with metal clamps or staples.

Hanging lean on load-bearing walls in two places, additional props are not used.

Therefore, if the planned slope is less than 45 degrees, the horizontal pressure will be greater than the vertical one, which means that it is worth considering emergency reinforcement. Therefore, it is necessary to carry out all the calculations before starting work and decide how to install the rafters in your case.

Rafter system for the future attic

The most common method of fastening are ties made of metal or wooden structures. The place of their installation is selected individually and directly depends on the desired functionality of the attic space. For example, if the roof will be used in the role, the screed should be at the base of the rafter legs.

Installation of load-bearing rafters for a gable roof

To create a reliable fastening of the entire roof, which can withstand heavy loads, you must use the combined installation method, i.e. installation of rafters will take place using two technologies - inclined and hanging.

For installation, high-quality beams with antiseptic treatment are best suited. The most common size is 49.9 * 149 * 5000 mm. If the length of the beam is greater than the specified, it is desirable to increase the height carrier beam up to 180 mm. The installation of the rafter system should be carried out in a parallel manner, that is, having mounted the rafter on one side, we immediately set it on the opposite side.

Preliminary marking and drilling of holes for fastenings is best done on the ground.

In order for the supports to be as stable as possible, it is advisable to make the lower grooves according to the diameter of the Mauerlat.

Having selected the upper section of the intersection, we proceed in the same way and make a tie-in equal to half the diameter of the beam.

When fastening with an overlap, top mount should work without additional protrusions.

In order for all the grooves to be of the same diameter, it is necessary to prepare a mortise template. The most common material for its manufacture is plywood or thick cardboard. According to a previously drawn up drawing, a layout is cut out of plywood in two copies, nailed to a beam on both sides and outlined with a pencil. The tie-in made according to this principle will turn out to be dense and as even as possible.

It is desirable to make cuts as simple as possible, since intricately cut joints can be absolutely unreliable.

As far as possible, the mounted planes should be perpendicular to the load forces that may appear along the wooden elements.

After creating the structure, it should be securely fixed to the Mauerlat. For this, ordinary nails or special anchors are suitable. The next step is to define minimum distance rafters from each other.

To determine it, look at the table.

Rafter leg length, m	Distance between adjacent rafters, cm
	110		140		175		213
	Rafter leg thickness, cm
	bars	logs	bars	logs	bars	logs	bars	logs
Less than 3	8 * 10	Ø 10	8 * 13	Ø 13	9 *10	Ø 10	9 * 16	Ø 16
3 to 3.5	8 * 13	Ø 13	8 * 16	Ø 16	8 *18	Ø 18	9 *18	Ø 18
3.6 to 4.2	8 * 16	Ø 16	8 * 18	Ø 18	9 *18	Ø 18	10 *20	Ø 18
4.2 to 4.9	8 * 18	Ø 18	8 * 20	Ø 20	10 *20	Ø 20	–	Ø –
4.9 to 5.7	8 * 20	Ø 20	10 * 20	Ø 20	–	Ø –	–	Ø –
5.7 to 6.2	10 * 20	Ø 20	12 *22	Ø 22	–	Ø –	–	Ø –

Trying on rafter legs

Below we consider the main aspects that will affect the choice of the section of the rafter leg:

• We find out what will be the constant pressure on the bars.
• Covering material used in a particular case.
• The desired angle of inclination of a shed or gable roof, which is easy to calculate if you use the advice from.
• Dimensions of the house and the estimated complexity of installation.
• Climatic conditions in your area. The calculation is the level of precipitation in summer and winter.
• The material and quality of the rafters themselves. by the most the best option there will be bars obtained from coniferous trees. But sometimes you can stumble upon a fake, so it's better to pick up more quality varieties so that the natural belonging of the material can be determined by wood.

The main characteristic of the wood used is its moisture content. A suitable level should be within 22 percent. If you wondered how to install rafters with high humidity? The answer is no! They need to dry well. The whole reason is that excessive moisture will evaporate over time, and the wood will shrink, which will cause it to warp and change in size, and this can lead to more Negative consequences, for example - a violation of tightness.

Let's move on to the legs. There are several reliable fasteners in use today. They can be used on all types of roofs. The reliability and correctness of attaching the rafters to the Mauerlat will depend on their execution:

• sliding;
• Rigid.

For both cases, you can use a varied combination of hanging and inclined rafters.

hard way it is applied for standard designs, which are installed without turns, bends. To use it, it is advisable to put risks on the bars in advance and make the appropriate cuts, followed by attaching the rafter leg to the Mauerlat.

sliding(very often called free mount) has several stages of fastening. This is done in order to leave a certain margin for the subsidence of the frame; it can be used in conjunction with poorly dried rafters.

It is difficult to overestimate the value correct installation rafters for the stability and durability of the roof.

Thus, by applying the basic knowledge gained from this article, you can not only control the process led by professionals, but also do most of the work yourself, while significantly reducing costs and saving time and nerves.

Good luck with your construction!

21.02.2017 1 Comment

The truss system of a gable roof is a simple design that is available for a do-it-yourself device even for a novice developer. It is only necessary to make preliminary calculations, familiarize yourself with the details and stages of the construction of the roof, and calculate the materials needed for installation. When calculating, it should be taken into account that load bearing capacity gable roof depends on the influence on it of loads from wind, snow, weight of materials.

In order to make the process of building a gable roof truss system as easy as possible for you, below is a detailed step-by-step instruction for installing a truss system with your own hands.

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Requirements for building materials

For the installation of a truss system, the best option would be to use sawn timber from coniferous wood - pine, spruce or larch, grades I - III.

The material for the rafters is taken not lower than grade II, the Mauerlat is made from boards or timber of grade II, for racks and girders material of grade II is taken, the lathing is made from grade II-III lumber, it depends on the roof. Crossbars, puffs are made of Grade I material. On linings, linings, material of grade III can be used.

Note! Lumber must be dry with a moisture content of not more than 20%. Before installation, it should be treated with flame retardants and antiseptics against fungal diseases.

You need to store lumber under a canopy, providing protection from the sun and moisture. Level the storage area, shift the lumber with linings for ventilation.

For installation, fasteners are required: ties, plates, studs, bolts with washers and nuts, self-tapping screws with EPDM gaskets, 2.8 mm thick, mounting tape, galvanized brackets.

Brackets are used when fastening the Mauerlat, they are fastened with nails or self-tapping screws.

KR corners serve to attach the rafters to the Mauerlat, prevent the rafters from moving.

All fasteners must be made from high quality material and have corrosion protection.

Tools for the construction of the truss system

To install the gable roof truss system, you will need the following set of tools:

• tape measure, different lengths 5, 10, 20 meters;
• markers, pencils;
• cord, for stretching;
• hammers, various purposes, nail puller;
• scissors, for cutting;
• roofing knife;
• putty knife;
• scotch;
• hacksaws, electric saw, electric drill with various drills and nozzles;
• screwdriver with nozzles;
• markings, horizontal and vertical levels;
• rails, rulers;
• mounting foam;
• safety belt and rope - for safe work.

Keep all roofing tools in a tool bag for safety.

Types of truss systems for a gable roof

sent rafters

Rely on Mauerlat and racks mounted on inner wall, with a step equal to the rafters. To give rigidity during spans of 6 m, struts are additionally placed.

The scheme of the rafters of a gable roof

hanging rafters

If the building is of a small width, it is possible to arrange a truss system when the rafters rest on the mauerlat or walls, without intermediate supports. The maximum span is 9 meters. Such roofs can sometimes be arranged without a Mauerlat. The rafters are installed on the wall, using gaskets, on the rafters in this embodiment, a bending moment acts.

To unload, put wooden or metal lining. They securely reinforce the corner. For hanging rafters longer span headstock and struts are installed. For hanging systems, the rafters are arranged with a larger section, and the lumber is chosen not lower than grade I II.

Scheme of hanging rafters of a gable roof

Calculation of the truss system

It is possible to determine the cross-section of a gable roof beam in the truss system by collecting all the loads acting on it: the weight of the coating, lathing, snow, wind pressure, precipitation.

Permanent loads can be determined by the weight of 1 m 2 of roofing, battens. It is important that the weight per 1 m 2 of the roof is in the range of 40-45 kg.

Variable loads from snow, wind are calculated from tabular values normative documents SNiP, depending on the height of the building, temperature zone. The load from snow is equal to its weight multiplied by a coefficient depending on the slope of the slope. All these calculations are carried out during the project.

And if there is no project, and the roof is being erected on a small building? You need to look at the construction of a house in the neighborhood, which is being carried out according to the project, the roof area is the same as your building. The gable roof truss system will serve as a model.

Rafter beam dimensions

On the top point a ridge is laid that connects the rafters. The height of the ridge depends on the slope of the roof. The slope is influenced by the choice of coating material. Minimum dimensions are:

• for tiled roofs, slate 22 gr.;
• for metal tiles - 14 gr.;
• ondulin - 6 gr.;
• corrugated board - 12 gr.

The optimal angle is 35-45 gr. slope, provides a quick discharge of water and snow. In regions with strong winds, roofs are made flat and then the angle of inclination is within 20-45 degrees.

You can determine the height by the formula: H \u003d 1 / 2 Lpr * tgA. Where A is the angle of inclination, L is the width of the building.

The task is simplified when using a ready-made table. The coefficient depends on the width of the building and the angle of inclination. Multiply the coefficient by 1⁄2 of the width of the building.

The rafters are made from pine or spruce bars, with a section of 50 × 100 mm, 50 * 150 mm.

The size of the rafters depends on the pitch. The pitch of the rafters is less, it is installed large quantity, the cross section will decrease. The distance between the rafters at a gable roof is in the range from 600 mm to 1800 mm, it all depends on the design of the roof and the materials used for its construction.

Table of rafter sizes, depending on the step of their installation

Length rafters, mm	Distance between rafters, mm	Rafter beam section size, mm
up to 3000	1200	80×100
up to 3000	1800	90×100
up to 4000	1000	80×160
up to 4000	1400	80×180
up to 4000	1800	90×180
up to 6000	1000	80×200
up to 6000	1400	100×200

The roof does not end at the level of the walls, it is extended 500 mm outwards. The rafter leg can protrude, or a board or bar is built up. In this case, moisture does not fall on the wall, the foundation is not poured.

Step-by-step installation of the design of the gable roof truss system

The gable roof truss system consists of the following elements:

1. Mauerlat.
2. Lie down.
3. Racks.
4. Rafter.
5. Struts.
6. Puffs.
7. Crate.

Mauerlat installation

Mauerlat fasteners to a monolithic reinforced concrete belt

Mauerlat evenly distributes the load on the walls of the building, its installation can be done in several ways:

• attached to the wall through reinforced reinforced concrete belt with studs;
• studs are inserted into the masonry;
• a simple and common way for simple roofs, fastening with wire rod.

For him, take a bar with a section of 100 × 100 mm, 150 × 150 mm or 200 × 200 mm. Which section to choose depends on the size of the roof and its coverage. The Mauerlat is joined along the length, for this, make a 100 mm cut, 500 mm long, fold the bars and fasten with studs.

In the corners, the Mauerlat is tied with cuts to the floor of the beam, fastened with brackets or bolts. At wooden buildings, Mauerlat is the last crown. On the brick walls, perform a monolithic reinforced reinforced concrete belt, with a section of 400 × 300 mm. Align the pins with a thread of 12 mm in diameter along the belt, through 120 mm, for fastening.

Drill holes with a diameter of 12 mm in the Mauerlat, lay them so that the pins go into the holes. Tighten with nuts from above. Previously, we lay two layers of roofing material or roofing felt under the bar. FROM outer side walls, mauerlat lay bricks. Laying the Mauerlat on a horizontally and vertically even base. It is necessary to check the horizontal level of the surface. Check diagonals. Align with pads if necessary.

Installation instructions for beds, racks, rafters, struts and puffs

Do-it-yourself do-it-yourself installation of a gable roof truss system is carried out in the following order:

1. To carry out the installation of the bed, with the sent rafters.
2. Mark the installation step of the rafter legs.
3. Prepare according to the size of the rack.
4. Install them, if necessary, unfasten them with spacers.
5. Lay a run. Check geometry. Install fastener.
6. Try on the first rafter leg, mark the cutting points.
7. Mark the points and install the rafters at the beginning and end of the roof, pull a cord between them in order to align the rest of the elements with it.
8. Having installed the rafter leg, we attach it first to the Mauerlat, then to the ridge run, to each other.
9. Screw every second leg with wire to the Mauerlat.

The fastening of the rafters to the Mauerlat is done with the help of notches, thrust corners and a hemmed support bar. Reinforce with nails or staples.

Methods for attaching rafters to the Mauerlat

Install the support posts on the beds or linings and linings. A bed is a beam 50 × 100 mm or 50 × 150 mm, laid on the middle wall along a roofing felt lining. Place brick columns under the lining, 2 bricks high.

The rafter legs are connected to each other on the ridge. Consider the common connection nodes of the truss system:

1. They make cuts at one leg and washed down at the other. Insert one leg into the cut of the other and fasten with a bolt.
2. Install overlays, wooden or metal.
3. With the help of cuts in the run, they are fixed with nails or bolts.

Methods for connecting rafters on a ridge

For the stability of the roof to wind loads, puffs, struts and runs are installed. The tightening is a bar 100 × 150 mm, runs and struts are made from a bar 50 × 150 mm or 100 × 150 mm.

With the installation of contractions, the reliability of the rafter design increases. The sections of the beam are the same as the rafters. They are attached to the legs with bolts or nails. The bracing device adds rigidity to the structure. They are installed tightly, to the surface of the rafters.

Lumber has a standard length of 6 m. Rafters can be longer. Then you need to connect them. There are several connection methods:

1. Fasten by applying bars on both sides at the junction, connect them with nails in a checkerboard pattern.
2. Overlap, one part of the rafter to another, at a distance of 1 meter, fasten with nails in a variable order.
3. Run a cut obliquely, cut out part of the legs of the rafters, connect them, reinforcing them with bolts.

Lathing device

A crate is laid along the roof rafters. It serves to distribute the load from the roofing material, snow on the rafters. It plays the role of an air gap between the roof and the truss system.

The design of the crate depends on the accepted roofing material:

• under soft tiles make the crate solid, an anti-condensate film is laid on the rafters, pressed against the top with a counter rail, the crate is nailed onto it, then the OSB boards and lining carpet, lay tiles on top.
• under the roof of the corrugated board, the crate should be sparse. The step of the lathing depends on the brand of corrugated board, its thickness and the angle of the roof.
• make a crate for standard slate in increments of 500 mm from a bar 75 × 75 mm or 50 × 50, as well as boards from 30 × 100 mm. Consideration should be given to the design features of the roof, with final choice suitable option.

The lumber from which the crate is made is pine of the first or second grade. It is advisable to take a width of no more than 14 cm. With a width of more, the boards can warp and damage the roofing. The length of the nails should be three times the thickness of the crate. Lay boards along the ridge. Install the first board greater thickness to the height of the roofing.

To arrange a continuous crate along the slope of the roof.

With the first layer, lay a board along the ridge from it at a distance of 500-1000 mm next, and so on. With the second layer, lay the crate in the direction along the rafters. Arrange the joint between the boards only on the rafters in a run. The nail is sunk completely with the head into the pulp of the wood.

Cornice overhangs

Arranged to protect against precipitation, play an aesthetic role. Eaves overhangs suit tightly without gaps. The final stage on roofing.

Scheme of the device of the eaves overhang of a gable roof

Gable

The gable roof has two gables. They have the shape of a triangle, with the apex at the ridge and the sides coincide with the slopes of the roof. Gables support rafters and enclose attic space. Protect from wind and precipitation, give stability to the roof.

AT wooden buildings the pediment is made frame. AT brick buildings, frame or brick. Gables made of brick or gas block are erected before the roofing device. They require very precise execution.

Frame gables fit into the finished opening when the truss system is already assembled.

The frame is made of bars or boards. The frame elements are connected on spikes or to the floor of a tree, all fastened with nails. They are sheathed by nailing boards, lining or siding, maintaining the color in the decoration of the facade of the building. For the device of a window opening, an additional frame is made under it according to the size of the window. If the attic is insulated, then the pediment also needs to be insulated. Insulation is laid in the middle of the frame. A mineral wool insulation with reduced flammability is used. From the outside, the frame is upholstered with a hydro-windproof film or windproof membrane, from the inside under finishing material nail the vapor barrier film or vapor barrier membrane.

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