How to saw rafters with a circular saw. How to make cutouts in rafters correctly. Making rafters: template and assembly Gasping down the rafter leg

Is it possible to highlight some main detail in the roof? This is unlikely to work, since here each element performs its own function. For example, rafters are a part of a roof that has slopes, which can be called a frame. It is on them that the roofing material will be laid and other elements will be attached. The final shape of the roof will depend on how the rafter system is assembled and installed. But if you do the work of creating the roof yourself, then how to attach the rafters? In fact, this is a rather complex stage of work, on which the strength, reliability, and even geometric correctness of the roof will depend.

The rafter system is a roof frame with slopes, assembled from the rafter legs themselves, as well as the mauerlat and ridge beam. The Mauerlat is a support beam that is located along the perimeter of the upper part of the walls of the house, and the ridge beam is installed directly in the upper part of the roof in the place where two opposite rafter legs are connected at an angle.

Designing a rafter system is an important task, during which it is necessary to correctly calculate the wind and snow loads that will fall on the roof, as well as take into account other parameters. The first indicators will depend on the climatic region in which the facility under construction will be located. Next, based on the data obtained, the thickness of the walls of the house itself (load-bearing) is calculated, and the quality and type of material for the roof itself is selected, the angle of inclination of its slopes and other points are calculated.

Attention! Shortcomings and errors made during the design can negatively affect the quality of the roof. In some cases, they can lead to rapid collapse or destruction of the roof.

The design of the rafter system may include the rafters themselves, the ties that will be located between them, purlins, additional supports - the so-called rafter legs - and other elements. The assembled rafter system usually rests on the same Mauerlat or on floor beams. Mauerlat helps to evenly distribute the load along the entire perimeter of the walls. This is the main difference between this method of fastening. If you attach the rafter system to the floor beams, that is, without installing a Mauerlat, then the main load will fall on the attachment points and not be distributed evenly over all walls.

On a note! The latter case is not an option if the walls are made of brick, which will begin to collapse over time in places experiencing maximum load. But for a wooden log house this method is quite suitable.

Table. Dependence of the cross-section of rafter legs on their length and pitch.

In previous articles that described the structure of the roof, we already said that the hanging rafters rest with their lower ends on the mauerlat, and the upper ends of adjacent rafters rest (either directly or through a ridge board) against each other. In the most simplified version, this is shown in Fig. 1:

Picture 1

I think it is obvious to everyone that with such an arrangement, bursting loads appear on the walls. To reduce them, tie downs are added to the truss. But let's talk about everything in order.

As an example, let’s take a house with a semi-attic in the Volgograd region. The sum of snow and wind loads is 155 kg/m2. The dimensions of the house box are 8x10 meters. The thickness of the walls is 50 cm. The angle of inclination of the slopes is 40° (see Fig. 2):

Figure 2

STEP 1: We install. In this design, in addition to the usual loads, pushing forces will act on it, tending to move it from the wall. For more reliable fastening, you can add metal fastening plates to the anchor bolts (or studs) (see Fig. 3). The plates can be secured to the wall, for example, with frame anchors, and to the Mauerlat using nails, self-tapping screws, and wood grouse.

Figure 3

STEP 2: We determine the required section of the rafters. We carry out the calculation in the “Arch” tab (see Fig. 4):

Figure 4

The cross-section of the rafters is taken to be 50x200 mm in increments of 60 cm.

A question may immediately arise here. Where do we get the distance from the ridge to the tie rod? For us it is 2 meters. Earlier on the site, we already said that before we start building a roof, we need to make a drawing of it on paper, always to scale (with all proportions respected). If you know how, you can draw on the computer. Further, using this drawing, we determine all the dimensions and angles that interest us.

Tie-downs are installed between hanging rafters to reduce bursting loads on the walls. The lower the tension, the more benefit it will provide. Those. the less bursting load there is on the walls. But since in our example the tie rods also serve as ceiling beams for the attic floor, we determine the height of their location based on the ceiling height we need. I took this height of 2.5 meters (see Fig. 5):

Figure 5

STEP 3: We make a template for the lower cut of the rafters. To do this, we take a piece of board of the desired section about a meter long, apply it to the mauerlat at our angle of inclination of the slopes of 40° (focus on the pediment) and make markings, as shown in Figure 6:

Figure 6

We draw the vertical and horizontal lines we need (shown in blue) using a level. The depth of the cut is 5 cm.

So, let's make a template.

STEP 4: We install a ridge board, through which all the rafters will be connected to each other. First you need to outline the location of its installation.

We take the template we made earlier and apply it to the Mauerlat. We are interested in the size shown in Figure 7 (here it is 18 cm):

Figure 7

Let's call the lowest point on the Mauerlat point “A”.

We transfer the resulting size to the top of the pediment, make markings in accordance with Figure 8:

Figure 8

We will designate the lower right corner as point “B”. Now we can measure the distance from the attic floor to point B (the length of the temporary racks).

We install strictly vertically temporary racks from 50x200 boards and place a ridge board of the same section on them. To fix them, you can put a board under the posts, secured with simple dowel nails to the floor slabs (see Fig. 9). There is no need to fasten it too much, then we will remove it. The distance between the posts is no more than 3 meters.

Figure 9

We attach the ridge board to the gables with metal brackets. The stability of the racks is ensured by the jibs.

Perhaps you could see somewhere how hanging rafters are installed without a ridge board (see figure on the left). I am very familiar with this method; we did this before too.

But when we tried the option with a ridge board, we settled on it. Despite the fact that it takes some time to install the racks and ridge boards, subsequent installation of the rafters is much more convenient and faster. As a result, in time you win. In addition, the design is more stable and more geometrically smooth.

STEP 5: We manufacture and install rafters.

We make a rafter like this: we take a board of the required length, apply a template to one end, mark it and make the bottom cut. Then use a tape measure to measure the distance between points “A” and “B” (see Fig. 7-8). We transfer this size to our workpiece and make the top cut. The angle we need for the top cut is on our template (see Fig. 10). For us it is 90°+40° = 130°

Figure 10

This is how we install all the rafters (see Fig. 11)

Figure 11

The connection of the rafters with the Mauerlat here does not look the same as it was, for example. I think you already understand that this is due to the presence of bursting loads, which were not present in that version. However, in future articles you will see that this option is just one of the possible, and not the only correct one. We will also use cuts that are more familiar to us. The main thing is to securely fasten the rafters to the Mauerlat.

At the top point, the rafters will protrude beyond the ridge board. You can drive small bars between them, or you can leave them as is. This, in principle, does not play any role (see Fig. 12):

Figure 12

We fasten the rafters to the ridge with nails or self-tapping screws. It is not necessary to install any additional fasteners here. In general, in this design, thanks to the lower gash, the rafters seem to be sandwiched between the Mauerlat and the ridge board.

STEP 6: We install the tightening.

We make them from boards of the same section as the rafters. It is not necessary to make any cuts or cuts here. We make the puffs overlapping the rafters. We fasten them with several nails and tighten them with a threaded rod with a diameter of 12-14 mm (see Fig. 13):

Figure 13

Thus, we install all the tightening and remove our temporary stands on which we placed the ridge board:

Figure 14

Now you can guess the purpose of the small windows in the upper part of the pediment. Through them, ventilation of the insulation will be carried out, which will lie on the ceiling of the semi-attic floor (between the puffs).

STEP 7: We attach the eaves overhang fillets to the lower ends of the rafters (see Fig. 15). We make them from boards with a section of 50x100 mm. We make the length of the filly such that we get the eaves overhang of the width we need (40-50 cm), and so that it overlaps the rafter by at least 50 cm. We fasten the filly with several nails and tighten it with 2 threaded rods. In the middle part, for additional support on the wall, you can fasten a small block to the fillet with nails or self-tapping screws.

Figure 15

Please note that at the junction of the overhang fillet with the mauerlat, we do not make a cut on it, because this will reduce its already small cross-section. Here we first make a small cut in the Mauerlat itself (see Fig. 16):

Figure 16

To make the cornice even, use lace. Place the outer fillies first, then pull the string between them and place the rest. In Figure 17, the lace is shown in blue.

Figure 17

Step 8: We already know the following steps from previous articles. We place the fillies on the pediment and attach the wind boards (see Fig. 18):

Figure 18

STEP 9: Now we can leave the cornices as they are.

Let's look at another version of the eaves overhangs (see Fig. 19):

Figure 19

These “earrings” are made from inch boards 10-15 cm wide. We fasten them with self-tapping screws.

Thus, now all we have to do is hem the siding belts to the bottom of the eaves; Having secured the protective film to the rafters, make a counter-lattice and sheathing; cover the roof with roofing material. We discussed these steps in previous articles. I think there is no point in repeating myself here and when considering other roof designs in the future.

Fastening rafters: considering methods

There are various ways to attach rafters when constructing a roof frame. The choice primarily depends on the design features of the rafter system. It is important that the fastening points have high strength and withstand operating loads characteristic of the climate of the region.

Rafter fasteners

To ensure reliable connection of the parts of the rafter system, special fasteners are used. Rafter fasteners are wooden and metal products that are used when installing components of the rafter system. These include wooden elements:

• bars;
• scarves (triangular overlays);
• dowel;
• thorns.

• nails;
• screws;
• bolts complete with washers and nuts;
• staples;
• clamps;
• overlays;
• loops;
• sliders/sleds;
• anchors;
• serrated plates;
• nail plates;
• corners;
• perforated tapes, etc.

The choice of rafter fasteners depends on the requirements for the strength of structural units, design loads and roof configuration.

Fastening the lower part of the rafter leg

The lower part of the rafter legs rests on the wall. Connecting rafters to walls can be done using various methods:

• through the Mauerlat;
• using rafters and tie-downs;
• through floor beams;
• using frame-type structure strapping;
• connection with the logs of the upper crown of wooden walls.

When installing hanging rafters, it is important to consider that the rafter legs, rigidly connected at the top, exert horizontal expansion pressure on the walls. To absorb the expansion forces, the opposing rafters are connected with a tie made of boards or timber. Thus, a non-thrust triangle is connected to the wall of the building.

An alternative to tightening can be floor beams that are laid perpendicular to the walls. This design without a Mauerlat is used for the construction of light attics, provided that the walls are able to withstand point loads. For example, attaching rafters to a brick wall necessarily requires the installation of a Mauerlat, since point loads are contraindicated for walls made of piece materials. To create a roof overhang, the beams must extend beyond the plane of the wall by at least 50 cm on each side. The rafter leg is also carried behind the wall and attached to the edge of the beam.

To prevent the roof from collapsing under loads, the attached rafter should not be able to slide along the beam, so a reliable connection must be ensured.

Basic methods of fastening to beams

The following options for fastening rafters are used, both independently and in combination:

• tooth with emphasis;
• tooth with a spike;
• emphasis at the end of the beam.

The use of one or two teeth is determined by the angle of inclination of the rafters. The above fastening methods allow you to transfer the load from one element of the rafter system to another.

Single-tooth cutting is used when installing roofs with slope angles greater than 35 degrees.. A tooth with a tenon is made in the heel of the rafter, a stop is cut out in the beam, in which a socket is provided for the tenon. The depth of the nest should not exceed 1/3 of the thickness of the beam. The cutting is carried out at a distance of 25-35 cm from the edge of the beam, extending beyond the plane of the house wall. The spike prevents lateral movement of the rafter leg.

For a roof with a smaller slope angle, the rafter legs are mounted in such a way as to increase the contact area between the rafter and the beam, thereby increasing the supporting area of ​​the structure. For this purpose, cutting into two tenons, into a lock or stop with a tenon or without a tenon, and other combinations is performed.

In addition to cutting, connecting rafter legs to beams can be done using a bolted connection or a bolt and a clamp.

Attaching the rafters to the mauerlat

Fastening the rafters to the wall is most often done using a mauerlat - a special support structure that allows you to evenly distribute the load from the roof onto the walls and foundation of the structure. Rafters can be mounted to the Mauerlat in two ways - using a rigid or sliding fastening.

With a rigid fastening method, the possibility of any interactions (shifts, bends, turns) between the connected structural elements is completely eliminated. This is achieved if:

• corners are used for fastening rafters with a hemmed support beam;
• a cut (saddle) is made on the rafter leg with further fastening of the connection with staples, nails and wire.

In the first case, the support of the rafter legs is carried out using a support beam. The rafter leg is firmly abutted along the pressure line, and then fixed with metal fasteners with a metal corner installed on the sides to prevent lateral displacement.

The second mounting option is used more often. In this case, the rafter fastening unit involves the use of nails, which are driven from the sides at an angle towards each other (crossing occurs inside the Mauerlat), and then the third nail is driven vertically into the lower part of the rafter.

Both types of fastening require additional fixation of the rafter legs to the walls of the building using wire rod and anchors.

Sliding (hinged) coupling of elements allows the rafters to be able to move somewhat relative to the Mauerlat within specified limits. Several fastening methods are used. This can be a rafter leg fastened to a bracket, a vertically driven nail, or two side nails driven in at an angle. Special sliding fastenings for rafters – “sleds” – are also used.

The sliding joint is mainly used in the construction of wooden houses from logs or timber. In this case, deformation of the rafter system during gradual shrinkage of the house is eliminated. Sliding joints in the attachment points of the rafters to the walls ensure gradual adjustment of the roof structure to changes in the geometry of the structure. The remaining roof elements are installed using standard technology.

Skate attachment

Attaching the rafters to the ridge has its own characteristics. The three most common installation methods are::

• end-to-end connection of rafter legs;
• fastening to the purlin (ridge beam);
• lap joint.

Connecting the upper parts of the rafter legs end to end is a simple and reliable installation method. The top edge of each rafter should be cut at an angle in accordance with the selected slope angle. Then the opposite rafters must be connected at the cut points and fastened with two nails from 150 mm. The nails must be driven in at an angle so that the parts that go into the opposite rafter are of sufficient length to ensure a tight fastener.

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How to strengthen rafters connected end-to-end? For this, it is recommended to use metal or wooden pads. The wooden overlay is fastened on both sides of the rafter pair in the area of ​​connection using nails, and the metal overlay - with bolts.

The connection of rafters on a purlin (ridge beam) is similar in execution to the first method. The rafter legs in the upper part are cut in the same way, but are mounted one at a time to a horizontal beam.

An overlapping rafter connection involves connecting the rafter legs not with cut ends, but with overlapping side planes. The connection is made using studs with washers or bolts. An overlap connection is the easiest way to install rafter legs.

To facilitate and simplify the installation of the rafter system, it is recommended to first make templates. For the template, take a board equal in length to the rafter leg, and make all the necessary cuts on it. Using a template, rafters are prepared on the ground, then fed to the roof and installed.

Installation of sheathing

The reliability of the roof largely depends on correctly executed sheathing. It can be continuous or sparse. The choice of type and pitch of sheathing depends on the roofing material used.

The sheathing is mounted from a bar or board, usually unedged. The timber is usually attached to the rafters (counter-lattice) with one nail at each attachment point. If the sheathing is made of boards, then the board is attached to each rafter with two nails driven in along the edges.

It is impossible to fasten the sheathing boards to one nail in the center on each rafter leg, since this installation method will not protect against twisting and damage to the roof deck under high loads.

The length of the lathing material is usually less than the length of the roof slope. Proper fastening of the sheathing to the rafters implies reliable splicing of boards or timber along the length. The joint should be on the rafter, and both ends of the spliced ​​elements are fastened with nails.

The joints of the sheathing elements should be made offset so that the joints on adjacent rows do not fall on the same rafter.

Before proceeding with the installation of the rafter system, it is recommended to choose the best option for how to secure the rafters.

Source: http://vseokrovle.com/stropilnaja/86-kreplenie-stropil.html

Fastening rafters: methods of fixing and connecting rafter legs

The rafter system is the frame of the roof of the house, which carries and evenly distributes the weight of the roofing pie, sometimes reaching up to 500 kg/m2. The reliability of this unique frame depends on three factors: the accuracy of the calculation, on the basis of which the number and cross-section of the supporting elements are selected, the material from which it is made, as well as the correctness of the fastening technology. Knowing how to properly fasten rafters, you can significantly increase the load-bearing capacity of the frame, making it stronger and more reliable. Installation errors, on the contrary, lead to significant losses in strength and deformation of the roof. In this article we will talk about the main types and methods of fastenings with which you can qualitatively install rafters with your own hands.

Main elements of the rafter frame

The rafter frame of the roof of a house is a system of interconnected supporting elements made of wood or metal that give the structure its shape, slope, and also evenly distribute its weight between the load-bearing walls. Its main component is the rafter legs, which are beams installed at an angle, which are connected in pairs along the slope, forming a ridge at the top point of their connection. There are two main types of rafters:

• Layered. Layered rafters are called supporting elements that have two points of support in the roof structure - on the ridge girder and the mauerlat. A rafter system of this type is used in structures that have one or more load-bearing walls inside on which rafters can be “leaned.” This fastening of the rafters allows you to relieve them through the use of additional vertical supports.
• Hanging. Hanging elements are those that have only one support point, located where the rafters are attached to the wall or mauerlat. A hanging type rafter system experiences load not only in bending, but also in expansion, so it is reinforced by horizontal compensating elements (crossbars, tie rods, tie rods).

Note! In most of the most popular rafter systems, the rafters are attached to the Mauerlat. Mauerlat is a massive beam or beam with a cross-section of 150x150 mm or 200x200 mm, laid along the load-bearing walls of the structure, on which the rafter legs will subsequently rest. It softens the pressure on the walls of the house and also evenly distributes the weight of the roofing pie. You can attach the Mauerlat to the upper chord of the walls using anchor bolts or embedded metal studs.

Main connecting nodes

The rafter frame is called a system because all its elements are closely interconnected and fixed, as a result of which the roof structure acquires a stable shape, rigidity and high load-bearing capacity. Each connecting node between its parts is a vulnerable point that can easily deform under load, so all fastenings must be carried out strictly according to technology. Experienced craftsmen identify the types of connections in the roof structure:

1. Attaching the rafters to the ridge beam. This connecting unit is typical only for layered rafter systems, in which the upper part of the rafter leg rests on a ridge girder mounted on vertical posts. The rafters can be attached to it using metal plates, nails or sliding slide fasteners.
2. Fastening the rafters to the mauerlat. The most important fastening point of the rafter frame is considered to be the junction of the mauerlat beam with the rafter legs. You can fix the rafters on it using nails, metal corners or wooden blocks.
3. Connecting the rafters to each other. To lengthen the rafter legs, if the length of the slope exceeds the standard length of lumber, they are assembled from several elements connected to each other using nails, glue or metal plates.
4. Connection of rafter legs with auxiliary supporting elements. In truss frame construction, rafters can be connected to tie rods, transoms, or struts to increase rigidity, strength, and load-bearing capacity.

Please note that any cuts made to attach the rafters to the beams, mauerlat or other structural elements of the frame lead to a decrease in their strength, so experienced craftsmen recommend connecting them together using corners and overlays.

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Fixation methods

When deciding how to attach rafters to a mauerlat or ridge girder, you need to choose the right fastening hardware. The modern construction market has a huge range of fasteners of various designs and sizes. The main criteria for choosing fasteners are the material used to make the rafters, their cross-section, as well as the type of load to which they are subjected. There are the following methods of fastening rafters:

• Using metal corners. Metal corners with holes for screws or nails are the most reliable and durable option for rigidly attaching rafters to the mauerlat, walls or ridge girder. They allow you to increase the rigidity and load-bearing capacity of the rafter frame structure many times over.

Experienced craftsmen believe that the most reliable way to fix rafters is to use metal corners that firmly connect the wooden elements to each other, rigidly fixing the angle between them. The corner that covers the joint between the rafter leg and the ridge beam or mauerlat serves as a kind of spacer between them.

Types of fastenings

Wood is a natural material that, in the process of equalizing humidity and drying, causes significant shrinkage, which is why the linear dimensions of the structure change. That is why experienced craftsmen recommend erecting a roof for timber and log houses a year after construction, when the shrinkage process passes from the active to the passive phase. If you fix the wooden frame elements rigidly, then after drying the roof of the house may become deformed. Therefore, the following types of fastenings are used to connect rafters:

1. Tough. Rigid fastenings are those types of fastening fittings that are not able to compensate for changes in the size of wood during the drying process. They provide a strong, reliable fixation, however, they can cause deformation of the frame, leading to changes in the geometry of the roof, leaks, or even collapse of the structure. This type of fastener includes metal corners, metal plates and wooden “chocks”.
2. Mobile. Movable fastenings are methods of fixation that, due to parts sliding along their axis, can compensate for changes in the dimensions of the rafter frame during the process of shrinkage of the structure. The frame, secured with sliders or slides, “breathes” along with the house, adapting to its dimensions without causing deformation. With the help of such fastenings it is possible to erect roofs for wooden houses that have not undergone the shrinkage process.

Interestingly, there are several options for combinations of movable and fixed connecting nodes. The most common are rafter systems with one rigid and two sliding fasteners, which provide sufficient mobility with high strength and rigidity of the structure.

Types of fasteners

There is ongoing debate among experienced roofers as to what is the most effective way to attach rafters to floor beams and mauerlat. However, in most cases the problem is that in these conditions it is more practical to use nails or self-tapping screws. Both of these fasteners have their own advantages and disadvantages:

• Nails are good because all you need to hammer them in is a hammer, which is available in every household. However, some craftsmen complain that hammering them in by hand takes too long. It is worth recalling that special jagged nails are used to fix the rafters, which securely adhere to the wood.
• To assemble the rafter frame, galvanized self-tapping screws are used, which are not afraid of corrosion. Due to the thread, they are firmly screwed into the thickness of the wood, securely fixing the elements together. Screwing them in quickly and conveniently with a portable screwdriver. The disadvantage of this type of fastener is that during dismantling, removing screws from wood is long and tedious.

Most experienced roofers agree that to fix rafter legs it is better to use galvanized rough nails, the length of which is 5-3 mm greater than the thickness of the lumber. Properly selected fasteners are the key to high-quality and long-term fixation of the roof frame, which will not be afraid of either mechanical stress or wind load.

The rafter system is the frame of the roof of the house, which carries and evenly distributes the weight of the roofing pie, sometimes reaching up to 500 kg/m2. The reliability of this unique frame depends on three factors: the accuracy of the calculation, on the basis of which the number and cross-section of the supporting elements are selected, the material from which it is made, as well as the correctness of the fastening technology. Knowing how to properly fasten rafters, you can significantly increase the load-bearing capacity of the frame, making it stronger and more reliable. Installation errors, on the contrary, lead to significant losses in strength and deformation of the roof. In this article we will talk about the main types and methods of fastenings with which you can qualitatively install rafters with your own hands.

The rafter frame of the roof of a house is a system of interconnected supporting elements made of wood or metal that give the structure its shape, slope, and also evenly distribute its weight between the load-bearing walls. Its main component is the rafter legs, which are beams installed at an angle, which are connected in pairs along the slope, forming a ridge at the top point of their connection. There are two main types of rafters:

• Layered. Layered rafters are called supporting elements that have two points of support in the roof structure - on the ridge girder and the mauerlat. A rafter system of this type is used in structures that have one or more load-bearing walls inside on which rafters can be “leaned.” This fastening of the rafters allows you to relieve them through the use of additional vertical supports.
• Hanging. Hanging elements are those that have only one support point, located where the rafters are attached to the wall or mauerlat. A hanging type rafter system experiences load not only in bending, but also in expansion, so it is reinforced by horizontal compensating elements (crossbars, tie rods, tie rods).

Note! In most of the most popular rafter systems, the rafters are attached to the Mauerlat. Mauerlat is a massive beam or beam with a cross-section of 150x150 mm or 200x200 mm, laid along the load-bearing walls of the structure, on which the rafter legs will subsequently rest. It softens the pressure on the walls of the house and also evenly distributes the weight of the roofing pie. You can attach the Mauerlat to the upper chord of the walls using anchor bolts or embedded metal studs.

Main connecting nodes

The rafter frame is called a system because all its elements are closely interconnected and fixed, as a result of which the roof structure acquires a stable shape, rigidity and high load-bearing capacity. Each connecting node between its parts is a vulnerable point that can easily deform under load, so all fastenings must be carried out strictly according to technology. Experienced craftsmen identify the types of connections in the roof structure:

1. Attaching the rafters to the ridge beam. This connecting unit is typical only for layered rafter systems, in which the upper part of the rafter leg rests on a ridge girder mounted on vertical posts. The rafters can be attached to it using metal plates, nails or sliding slide fasteners.
2. Fastening the rafters to the mauerlat. The most important fastening point of the rafter frame is considered to be the junction of the mauerlat beam with the rafter legs. You can fix the rafters on it using nails, metal corners or wooden blocks.
3. Connecting the rafters to each other. To lengthen the rafter legs, if the length of the slope exceeds the standard length of lumber, they are assembled from several elements connected to each other using nails, glue or metal plates.
4. Connection of rafter legs with auxiliary supporting elements. In truss frame construction, rafters can be connected to tie rods, transoms, or struts to increase rigidity, strength, and load-bearing capacity.

Please note that any cuts made to attach the rafters to the beams, mauerlat or other structural elements of the frame lead to a decrease in their strength, so experienced craftsmen recommend connecting them together using corners and overlays.

Fixation methods

When deciding how to attach rafters to a mauerlat or ridge girder, you need to choose the right fastening hardware. The modern construction market has a huge range of fasteners of various designs and sizes. The main criteria for choosing fasteners are the material used to make the rafters, their cross-section, as well as the type of load to which they are subjected. There are the following methods of fastening rafters:

Experienced craftsmen believe that the most reliable way to fix rafters is to use metal corners that firmly connect the wooden elements to each other, rigidly fixing the angle between them. The corner that covers the joint between the rafter leg and the ridge beam or mauerlat serves as a kind of spacer between them.

Types of fastenings

Wood is a natural material that, in the process of equalizing humidity and drying, causes significant shrinkage, which is why the linear dimensions of the structure change. That is why experienced craftsmen recommend erecting a roof for timber and log houses a year after construction, when the shrinkage process passes from the active to the passive phase. If you fix the wooden frame elements rigidly, then after drying the roof of the house may become deformed. Therefore, the following types of fastenings are used to connect rafters:

Interestingly, there are several options for combinations of movable and fixed connecting nodes. The most common are rafter systems with one rigid and two sliding fasteners, which provide sufficient mobility with high strength and rigidity of the structure.

Types of fasteners

There is ongoing debate among experienced roofers as to what is the most effective way to attach rafters to floor beams and mauerlat. However, in most cases the problem is that in these conditions it is more practical to use nails or self-tapping screws. Both of these fasteners have their own advantages and disadvantages:

• Nails are good because all you need to hammer them in is a hammer, which is available in every household. However, some craftsmen complain that hammering them in by hand takes too long. It is worth recalling that special jagged nails are used to fix the rafters, which securely adhere to the wood.
• To assemble the rafter frame, galvanized self-tapping screws are used, which are not afraid of corrosion. Due to the thread, they are firmly screwed into the thickness of the wood, securely fixing the elements together. Screwing them in quickly and conveniently with a portable screwdriver. The disadvantage of this type of fastener is that during dismantling, removing screws from wood is long and tedious.

Most experienced roofers agree that to fix rafter legs it is better to use galvanized rough nails, the length of which is 5-3 mm greater than the thickness of the lumber. Properly selected fasteners are the key to high-quality and long-term fixation of the roof frame, which will not be afraid of either mechanical stress or wind load.

Video instruction

The rafter system is the “skeleton” of any roofing structure. The reliability, quality and durability of the roof directly depends on the correctness of its manufacture and installation. If desired, you can handle the arrangement of the rafter system yourself. Want to know how? Check out the following guide!

There are layered and hanging rafter systems. According to statistics, layered structures are most often used. When arranging such a system, they run into the Mauerlat. The function of the central part is performed by a simple ridge run. To increase the strength of the system, supporting beams are installed.

In the case of hanging rafters, the system design is equipped with additional racks that promote optimal load distribution over the entire area of ​​the roof structure.

We take an extra pair of nails and fix the angle set between the boards. The template is ready. Additionally, secure it with a crossbar. To ensure that the set slope angle of the roof slope does not change under the influence of loads, fasten the crossbar with self-tapping screws.

Be extremely careful when creating the template. Even the slightest deviations can cause the entire structure to deteriorate.

Next, we make a new template for preparing mounting cuts on the system elements. Use plywood 0.5 cm thick. For reinforcement, use a 2.5 cm board. Select the dimensions of the cuts taking into account the cross-section of the rafters used.

Using ready-made templates, we make cuts and begin to assemble the truss.

Video - Gable roof rafter system

Farm assembly procedure

The structure includes supporting legs and connecting components. The farm resembles a triangle. Perform the work in the specified sequence, and the finished structure will be able to adequately withstand all incoming

The farm can be made on the ground with further rise to the top, or directly on the roof. The first option is simpler and easier to implement.

We assemble the truss in the following order. First, we cut the prepared material to the required size, join the bars at the top edges and fasten them with screws. To prevent cracks from appearing at the fastening points, we pre-drill holes in the bars with a diameter slightly smaller than the size of the fasteners.

We also use a crossbar to connect the rafter legs. We fix it half a meter below the top point of fastening the elements. Crossbars will help increase the rigidity of the structure and eliminate the risk of deflection. We fasten the crossbars in recesses previously prepared in the rafters by cutting down.

If necessary, the rafters are cut at an angle if this is required by the features of the roofing structure being installed.

Installation of a roof truss

The installation of roof trusses is carried out in the following sequence:

• we install end trusses;
• we fix the central trusses.

When installing edge trusses, we adhere to the following important rules:

After completing the installation of the outer trusses, we proceed to fixing the central and subsequent structures, if their placement is provided for by the project. The optimal installation step for trusses is 100 cm.

To secure the central rafter triangle, we use temporary jibs. After the visor is installed, the jibs can be removed. Recommendations for fastening the central and other trusses are the same as in the case of the outer structures.

After installing all structural elements, we begin attaching the sheathing and further arranging the roofing system: moisture, heat and vapor insulation, as well as installation of the selected finishing coating.

Good luck!