How to increase the logs for the roof. Splicing timber along the length. Corner connection with remainder

The roof is a complex, multi-component structure, the design, assembly and installation of which is a serious obstacle for an inexperienced craftsman. The most important stage the construction of the roof is considered the device of the truss frame, which sets the shape, slope and load-bearing capacity of the slope. The rafters bear the load from the weight of the roofing material and snow, so they must be strong and durable. But what if the length of the slope is much greater than standard size lumber? In this article, we will tell you how to properly splice the rafters together to increase the length of this element.

Rafter legs or rafters are the main elements of the roof truss frame, which are arranged in pairs along the ridge joint, forming inclined slope planes. They are usually made from healthy, durable wood or metal profile. In the construction of the roof, the rafters perform the following functions:

• Form the shapes and angle of inclination of the slopes. It is the angle between the rafters and the base of the roof that sets the recognizable geometry of the roof, facilitating the descent of melt and rain water and snow from the surface of the slope.
• Distribute weight evenly roofing. roofing cake taking into account the snow load, it can weigh up to 300 kg / m2, therefore the rafters must withstand significant weight along the entire length, and also distribute it between the bearing walls.
• They serve as the basis for fixing the roofing material. The finish coating is attached to the crate, nailed across the rafter legs of the frame.

Note! There are three rafter parameters that are determined when calculating and creating a roof project: the length of the rafter leg, the distance between them and the size of the section of these elements. They mainly depend on the slope of the slopes, climatic conditions and weight of the finish.

materials

Rafter legs distributing weight waterproofing coating and thermal insulation of the roof between the bearing walls, on which the slopes rest, must have a high bearing capacity and excellent strength properties. In addition, they must be lightweight so that, with their considerable length, they do not bend under their own weight. Optimal materials for the manufacture of rafters consider:

1. Wood. Wood - light, durable construction material, which is easy to handle with the most primitive tool by hand. Rafter legs from this beam with a section of 100x100 mm or 150x150 mm can withstand up to 500 kg / m2. Due to the fact that the standard size of lumber does not exceed 6 m, the tree is used for the manufacture of private rafters, because with a slope length exceeding 6 meters, it is necessary to build up the boards. The disadvantage of wooden rafters is considered to be poor resistance to decay, so they are treated with antiseptic compounds.
2. Metal. Metal rafters are used mainly in industrial construction, since household, commercial and industrial buildings, as a rule, have big size. high load bearing capacity metal profile allows you to use elements of a smaller section. In addition, the metal is highly resistant to corrosion.

Experienced craftsmen note that even if the slope length exceeds 6 meters, the rafters for the roof frame can be made of wood. Moreover, it is not necessary to purchase expensive lumber of non-standard length. At big size roofs carry out splicing of rafters or put them up with fillies.

Extension methods

The length of the rafter leg is the sum of the length of the slope and the length of the roof overhang, so it can exceed the standard size of lumber, which is 6 meters. To lengthen the boards from which the rafters are made, you need to connect two or three boards together. In order for the type-setting rafter leg not to lose its strength qualities, it is necessary to correctly calculate the place of splicing and securely fix it using one of the following methods.

Timber joints in the corners and straight walls of the house require strength and tightness. For tightness log house Humidity has a huge effect on building materials. If you build a house from a bar natural humidity, during shrinkage and shrinkage, the log house will experience significant internal stresses which can lead to deformation.

Using lumber that has been dried up to 20%, you can kill several problems at once in the bud - cracks, cracks, heavy draft, etc. Ideally, use profiled or glued beams from kiln-dried lamellas for a log house. The shrinkage of such a log house will be minimal.

The second method to avoid blowing corners is to make these corners with special, complex forms of connections.

The corners must be strong. The log house is affected by forces from possible ground movements, from its own weight and the weight of the roof, roof and snow, as well as pressure from the force of the wind. The corners must withstand all loads, and in addition, withstand deformations from fluctuations in linear dimensions due to rain, snow and changes in the heat and humidity regime.

Corner connection with remainder

Very important advantages of this type of felling:

• Blowing from the street is minimal, even with strong wind and in frost;
• High reliability. Even not fixed with dowels, the beams, connected at the corners by one of the types of cutting with the remainder, do not move even with moderate movements of the base soils under the action of heaving or seismic. The lower crowns hold the weight of the upper ones and the tight connection of the corners.

The main types of felling with residue

Cutting method with a one-sided locking groove

This method is equally good for both square timber and profiled. One side of the timber is sawn to form a groove perpendicular to the axis of the timber. The thickness of the groove is equal to half the thickness of the beam, the width and length of the groove are the same. The lock is obtained when this groove accommodates ½ of the timber located perpendicular to it. Such a crown is tightly fixed in relation to the underlying crown in one direction. Additional fixation with dowels gives the corner sufficient strength.

Cutting with a double-sided lock groove

This type of felling is a little more complicated - you will have to choose the grooves from both the upper edge of the beam and the bottom. The grooves in this case have the same width as in the one-sided groove method and a depth equal to ¼ of the thickness. Bilateral sampling of grooves takes twice as much time and requires greater accuracy, but it gives an undeniable advantage - the rigid fixation of each pair of bars not in one, but in two directions. That is, there is already spatial rigidity. Now, with any temperature and humidity fluctuations, the shift of bars and crowns relative to each other is practically impossible.

Cutting with a four-sided lock groove

A very complex cutting, the grooves can be both symmetrical and asymmetric, and it is extremely laborious to select such a complex groove manually. Typically, such complex grooves with ideal geometry are made on equipment that produces house kits. Then, at the construction site, these sets are assembled from numbered bars, like Lego constructors.

Complex and expensive processing, but no practical improvement in the tightness of the corner is observed, although in theory such an angle should become completely ideal.

The main types of felling without residue

An angle without residue saves on lumber. The bar is entirely in the plane of the wall, the ends do not protrude outward. But the overall savings are not observed, since these angles require additional insulation and caulks. In terms of strength, reliability and protection against blowing, these types of felling are also inferior to corners felled with the remainder. Competition can only be warm corner, he is a root spike.

Cutting without residue allows you to make the facade of the house more strict geometrically, it is easier to perform exterior finish. The issue of aesthetics is debatable, and more related to style.

Without a trace, corners are cut both from a square bar and from a profiled one.

Butt cutting without residue

The simplest and fast way for the construction of a farm building. None additional processing not required, just stack the bars of the desired lengths in a checkerboard pattern. So that the bars in the crowns and the crowns themselves do not move relative to each other, with this cutting method, fasteners are necessarily used - galvanized steel overhead plates, steel brackets or wooden dowels.

Labor costs in this case are minimal, carpentry experience may be completely absent. If you make a log house in this way from dried timber, you can get an acceptable result. From raw lumber, as carpenters say, with any effort, the corner will walk after shrinkage. The corner is deformed, and fluctuations in humidity will contribute to linear fluctuations, as a result, blown gaps will appear.

Butt cutting on dowels

The key can be different shapes. For a straight key, you will need to choose straight grooves along the ends and side surfaces of adjacent bars. Under the dovetail key, it is required to choose a rather complex groove, with broadenings from the middle. The key also has complex shape.

The connection with a straight key will prevent the crown bars from moving in the horizontal plane, but not in the vertical one. Vertically, the crowns will be held only by their own weight and the weight of the overlying structures. The dovetail key will securely fix the angle and prevent the bars from moving in both directions. This method of cutting without residue gives a practically windproof corner.

Cutting in half a tree

Also an easy cut. At the ends of the bars, cuts are made for ½ thickness, a spike is obtained that is the same in length and width. Without fixing with dowels, this connection will not be reliable. After shrinkage and settlement of the log house, the corner will most likely be blown through and will require additional insulation. The second caulk of log cabins after exposure and precipitation is always done.

As with butt cutting, you can modify this method by securing the corners with dowels. In this case, the bars will not move.

You can still improve the method of cutting into half a tree, if you join the ends into a paw. The paw has a more complex shape - the cuts are made oblique, wedge-shaped, exactly in size. The result is an increase in the strength of the log house, the beams are fixed relative to each other in the crowns, and the weight of the overlying crowns prevents the displacement of the underlying ones. The corner looks aesthetically pleasing from the inside and outside, the facade of the house is geometric, smooth.

Connection in a warm corner (in the root spike)

It is considered the warmest, windproof connection and at the same time guarantees the fixation of the crowns. The method is not the most difficult:

The ends are cut, leaving spikes, and the length and width of which should be exactly 1/3 of the beam section. A simpler spike has the shape of a rectangle, a more difficult one has a spike with one-sided widening. The grooves of the joined beams are selected according to the size of these spikes, but without an exact fit, since the grooves need to be caulked with moss, linen or jute fiber, hemp or felt. Bars with spikes are upset from above on bars with grooves. Fastening the crowns with dowels is mandatory for this cutting method.

Fastening the beams with dowels

• The classic wood for dowels is birch, free of defects, knots and slant, and also with a parallel arrangement of fibers relative to the longitudinal axis.
• The optimal length of the dowels is 0.8 of the sum of the heights of the two connected crowns. Sometimes not two, but three beams are connected with one dowel. Dowel diameters from 25 to 35 mm.
• Nagels are installed in the interval up to 1.5 m, and always on both sides of each corner. On the horizontal rows, the dowels are shifted in a checkerboard pattern.

Connections of bars along the length

Long, straight sections of walls can exceed the length of the lumber. The splicing of the timber along the length is done in one plane. The requirements for joints are the same as for corners - strength and tightness.

The easiest way to join a beam along the length is a connection on rectangular dowels. The crowns will be securely fixed in the transverse direction, such a joint will not be blown. The key is cut a little less than the groove to leave gaps for the caulk. The grooves for the dowel are sealed with moss, jute and linen fiber, and other material.

Harder and more efficient way joining the beams with a root spike. Direct splicing is technologically a bit simpler than angular splicing, but it also requires accuracy. The gaps between the groove and the spike should be several mm in order to pave them with a caulk.

The most complex, costly in terms of material and labor, and at the same time the best type of splicing in a straight line in terms of result is docking with an oblique lock. Dimensions must be accurate, fit close to perfect. The lock configuration is not easy. As a result, two beams have two completely overlapped sections in the joint, which gives strength to the joint, and the cunning shape of the oblique lock makes it impossible for a gap to appear even with significant shrinkage.

In individual buildings, the most popular wooden truss system - the supporting base of the vast majority of roofs in the private sector is made of wood.

Each roof has individual sizes and configuration, and it is often necessary to use support beams with non-standard parameters.

Rafters are:

• from a bar;
• from the board.

Factors affecting lumber parameters

wood for truss system choose well-dried, with a small number of knots and other defects. Typically applied conifers, easy to process and additionally impregnated with antiseptics and flame retardants.

For each element of the system - a strut, a rack or a rafter - the section and length are calculated.

The parameters of the support beams are affected by the angle of the roof, the geometry of the slope, the distance between the ridge and the Mauerlat, the distance between the rafter legs and the calculated load on the rafters, which includes the weight of the roofing, the weight of the batten, wind and snow loads.

Competent calculation in without fail must take into account all of these factors.

Connection methods for increasing the length

Rafters, the length of which is more than the usual six meters, are made to order in a production way.

However, in this case, along with the length, the thickness of the beam also increases, which is not always justified: after all, the appearance excess weight in the roof structure is undesirable, and the price of such rafters will be twice as high.

Therefore, most often builders resort to splicing rafters.

The joining of the bars does not provide sufficient bending rigidity, and therefore the junction of the two elements should be located as close as possible to the support - at a distance not exceeding 15 percent of the length of the entire main run.

The lengthening of the rafter legs from the timber is carried out in three main ways.

The ends of the spliced ​​beams must be cut strictly at an angle of 90 degrees to prevent deflection at the junction.

On both sides, the joining point is fixed with lumber overlays. The linings, in turn, are fixed with nails.

The connection with a steel toothed plate is also widespread.

In case of application metal elements should not be forgotten about anti-corrosion coating- in order to prevent wood decay and not reduce the reliability of the entire truss system.

Connection by the method of oblique cutting

The ends of the elements that will be joined are sawn in a special way - at an angle of 45 degrees.

The joining bars should be tightly fitted, it is necessary to achieve the most even joining surfaces by sanding.

In the middle of the connection, a through hole is made for a 12 or 14 mm bolt, which fixes the docking.

This is the easiest way to perform, the connection comes out tough, reliable. One rafter is superimposed on another so that the overlap is at least
100 cm.

How the edges of the rafters are cut off at the same time does not matter.

The connection is fixed in two ways:

• with nails. In order not to split the rafters, the nails are driven in alternately - in a checkerboard pattern;
• using pins. Studs are inserted into pre-prepared holes, fixed with washers and nuts. This option is considered more reliable.

Composite and paired boards, reinforcement of rafters

If the attic is planned to be made cold, it is more expedient to use a rafter system from boards.

Their advantages are lightness in comparison with bars and more. low price with no less strength.

To get a composite rafter, two identical boards are placed on the edge, and a third is inserted between them.

All wooden elements should be equal in width, the length of the third board varies depending on required size rafters.

The resulting gap is filled with scraps, and the entire structure is fixed with nails, driving them in a checkerboard pattern.

The rafters connected in this way must not be used as diagonal ones.

Paired rafters are more reliable: the boards are connected immediately and end-to-end and overlap.

To increase the width, strengthen the rafters, additional boards are used, achieving the optimal ratio of length and width in accordance with the calculated load.

The roof overhang protects the walls from rain and snow and drains water away from the roof. Its standard size is 40 cm.

If the rafter leg does not protrude beyond the wall of the building to the required length, it is increased by nailing a board - the so-called "filly".
"Fire" can be lighter and narrower than the main beam.

Fasteners and prefabricated rafters

Additionally, each connection is reinforced with metal plates, brackets or corners.

Holes for fasteners are made following this rule: the diameter of the drill should be 1 mm smaller than the diameter of the bolt.

Metal needle plates make it possible to significantly facilitate the construction of the roof, they are simply mounted and securely fasten the elements of the truss system.

Recently, prefabricated rafters prepared for installation have been produced in a factory way. The transportation of such items is very convenient.

Already at the construction site, with the help of needle plates from several parts, rafter legs required parameters.

Prefabricated elements can be made not only of wood, but also of metal.

All work on the construction of the rafter system, the formation of nodes and the extension of rafters must be carried out carefully, since the repair and replacement of rafters - difficult process requiring significant labor and material investment.

If you strictly adhere to the technology, all the rules and recommendations, then the roof will turn out to be reliable and durable.

When building a house from a bar, some elements cannot be assembled from solid material, because. its length is not enough. Connect the timber to have in the corners and in length. The connection of a beam in length can be found, for example, when assembling a wall more than 6 m in length. How do you do the connections in length with your own hands and their differences can be found in this article.

For splicing a beam with a length of more than 6 m (the length of a standard material), do-it-yourself use the types of connections:

1. Spike on keys (longitudinal).
2. Oblique castle.
3. Root tenon (longitudinal).
4. Splicing into the floor of a tree.
5. Attachment

Dowel joint

Doweled tongue joints are one of the most durable timber splicing options for building a timber house. The mechanism for connecting in length in this way is as follows: identical grooves are cut in two bars. After laying the sawn material to each other with sawn elements, a key is driven into the groove.

A key is an insert - a wedge that is made of hardwood or metal. A key made of wood, such as aspen, is suitable for timber. Getting into the sawn groove, the key tightly connects the two elements.

The shape of the key can be different: prismatic, rectangular, dovetail, straight and with notches.

Connection in an oblique lock

In terms of complexity, the connection of the beam into the “oblique lock” is one of the most difficult. Doing this on your own without knowledge will not work. But the strength of such a bundle exceeds many. In companies performing such work, they do not advertise this type, since the productivity of work will drop significantly.

The connection is made by sawing from two ends of the beam oblique, with certain bends at an angle with full compliance with the dimensions. It turns out, as it were, a spike and a groove that form a lock. Then these two sawn parts are superimposed on one another, connecting the timber. Additionally, the connection is fastened with two wooden dowels.

Connection in root tenon

This is also a key connection, which is performed by professionals. For such splicing, a spike is sawn on one end of the beam, and a groove on the other. They are cut at an angle of 450. It differs from the previous one in the form of a nodal connection. A similar connection is used for the corners of the log house. The spike and groove resemble a trapezoid ("dovetail"). Reinforced with additional dowels. With such a connection, the timber will not move horizontally from one another.

Splicing "tree floor"

When splicing into a “half-tree”, an angle is cut in the timber for half the section. In one drank with an angle down in the other up. They are connected by applying one beam to another. The disadvantage of such a connection is that the material loses part of its thickness at the junction, which means that the quality characteristics of the timber are falling.
To give strength, the connection is strengthened with dowels made of wood or iron; iron staples can also be used. Such a connection is simple in design and you can do it yourself.

Splicing by applying

This is the easiest way to connect two beam links together. To do this, the timber is applied with the ends to each other and spliced ​​with iron building brackets. Additional strength is achieved by pins, which are driven into the previous row of timber and at the junction at the junction of their 2.

How to choose the right connection

You can splice a beam into half a tree or end-to-end with your own hands, but such a connection does not have sufficient reliability and stability. For reinforcement, various construction fasteners for a bar (o).

Such methods of merging with each other cannot be used for the construction of load-bearing walls from timber. Experienced specialists will not use non-solid material on load-bearing walls. A longitudinal connection is permissible only in extreme cases, when it is not possible to acquire the material of the required length. But the walls in this case lose a number of their quality characteristics, including strength.

It is possible to interconnect with each other using a spike on the dowels for the construction of a house from glued laminated timber, since this solid construction having rigidity. But the quality of the key must be high.

If we talk about lock joints (oblique lock), then this is a rigid structure that I allow for use on load-bearing walls. But you won't be able to connect manually. When performing this splicing, it is necessary to observe the full accuracy of proportions for all parts of the drank. And the masters will take for such work from 1100 rubles / per connection. Of course, the costs will be justified, since the strength of the walls will not be inferior to solid material.

Features of joining profiled material

Profiled timber can also be joined along the length. Such docking is performed in accordance with GOST 30974-2002 “Connection of corner wooden and log low-rise structures. Dimensions, construction and classification.» These requirements are not considered mandatory and apply mainly to T-joints and corner joints of profiled timber. It is during certification that profiled timber is subject to verification for this GOST.

According to this documentation, the construction of a house from a profiled beam is joined in length to each other according to the following indicators:

1. Internal walls and non-bearing walls (profiled timber 80-220 mm long).
2. outdoor bearing walls(profiled timber 100-260 mm long).

When joining a profiled beam along the length, special chamfers must be provided for in the design of the material, along which water will be drained from the joint. Chamfers have a size of 20x20 or 15x15 mm.

You can watch a short video about how professionals join profiled timber. In this video, we observe the dovetail connection in the corners and along the length of the beam:

What you need to know for longitudinal docking with your own hands

1. Usually, the connection of the beam along the length is done at standard designs when one wall is longer than the other. The binding is done on one side, in the next row on the other. So the joints are staggered, and the wall looks more aesthetically pleasing. In addition, the location of one joint above the other violates the strength and integrity of the timber structure.
2. The type of splicing is chosen depending on the position of the timber in the structure of the house. The point is the load, which in various places can be: compression, stretching and bending.
3. Dowels and dowels are selected or made only from dense types of wood with a moisture content not lower than that of the beam itself by 2-5%. otherwise, they, having absorbed moisture, can damage bar locks.
4. Docking points must have an accurate and flat surface. Before laying, they must be treated with antiseptics, since after this it will not work.
5. All joints, both angular and longitudinal, must be insulated. Warming is carried out even at the time of installation, laying the knot with flax fiber.

When performing longitudinal joining of the beam, do not forget about the moisture content of the material. The knots of the material of natural moisture, when dried, may disperse and deep cracks will appear in them. Additional caulking at the joints must be carried out more carefully. It is better to connect a dry profiled beam into a spike or an oblique lock, so the walls do not lose their strength. And if you entrust the work to professionals, then the knots will be not only durable but also aesthetically attractive.

All photos from the article

This article is about how to splice a beam along the length. It is clear that for products operated without load, with a load in tension, bending and compression, different ways splicing. We will try to get to know them and formulate rules that will make the connection not only strong, but also beautiful.

Without load

The simplest scenario is splicing a part that does not experience operational loads. The most characteristic example is the crown of a wall made of timber.

The only requirement for the connection is that it should not be purged.

To clarify: the splicing points must necessarily shift from crown to crown. Otherwise mechanical strength walls can still be damaged.

• The simplest solution is a half-tree join. Each of the parts is cut to half the thickness; splicing length should not be less than the transverse dimension of the timber. Sealing of the connection is provided by laying insulation (usually jute tape). Often the connection is made vertical; thus the probability of blowing is reduced to zero;

• Connecting with a main tenon is not much more difficult. On one of the parts to be joined, a spike is cut with a size of 1/3 - 1/4 of the thickness of the beam, on the second - the corresponding groove;

• Another option for splicing a crown is a key connection.. The grooves are selected on both bars; after laying the crown, a wooden dowel is driven into them.

This type of load is typical for a variety of racks and columns.

Here, the builder has two tasks:

1. Avoid increasing the section of the part;
2. Eliminate the slightest possibility of mutual displacement of structural elements.

To achieve these goals, a lock is formed at the ends of the timber.

• A simple lap joint implies that the timber to be spliced ​​has a negligible thickness (which is quite typical for rafters). The length of the overlap should be at least three times the width of the beam or board. For fixing, bolts or studs are used;

• Butt splicing is also practiced, but with the obligatory strengthening of the connection with side plates. They can be made of board or thick plywood; perforated galvanized steel plates can also be used.

Furniture, railings

Instructions for splicing bars with self-manufacturing furniture or fences inside the house is markedly different from the recommendations relevant for rafters or beams. In this case, aesthetics come first.

How to make a connection with your own hands, which will be not only strong, but also beautiful?

Recall: pressing is mandatory and should take at least 5-6 seconds. Then the part is fixed in a fixed position while the glue dries.

Mill for selection of thorns. The price of the product is from 200 to 800 rubles, depending on the size.

However, the result is highly dependent on a number of subtleties.

1. The bar is selected by color and texture;
2. The wood species must be the same. Humidity can vary within three percent;
3. Defects on the spliced ​​elements should be placed on one side - the back;
4. No more than a day should pass between cutting the spikes and gluing. Otherwise, uneven drying of the wood will affect the accuracy of the fit of the spikes and the quality of the glue line;
5. Excess glue squeezed out during pressing is removed immediately. After it dries, it will be much more difficult to clean the part.

Conclusion