Independent construction of the roof of a private house. How to strengthen hanging rafters Repairing rafter legs

One of the most important stages of building a house is installing the roof, because for this you need to choose best option rafter locations. To build a roof yourself, you need to consider several options for installing the roof, and also learn about the sequence of actions performed.

Rafter system design

For each house, you should design a rafter system that is suitable specifically for this building. If this is not done, the load will be distributed unevenly, which can lead to the roof skewing.

To create the right project, keep in mind that:

1. If it is necessary to lay insulation, the rafter system must be done in such a way as to facilitate further work. Insulation materials are usually sold in width
2. 1200 mm, so the pitch between the rafters should be selected taking into account this particular characteristic. Otherwise, the insulation will have to be constantly trimmed.
3. The power of the supports is determined by the cross-section of the timber from which they are made. Attention is also paid to the condition of the wood. It is better to choose resin beams, as they last longer.

Pre-treatment of wood and preparatory work

Before starting work, the timber must be processed special compounds so that it is protected from exposure to microorganisms and fire. The application of antiseptic occurs before installation. Apply the composition using hard brushes.

In order for the composition to protect the wood for as long as possible, it is applied in two layers (the material is dried before this). Installation of rafters on the roof occurs only after the applied compounds have completely dried.

Preparation begins with checking all walls and ceilings, as well as taking measurements. If in some places the wall deviates from the horizontal, this can be corrected using cement screed. If the house is built from wood, unevenness is removed by installing wood underlays.

To facilitate the work, scaffolding is installed. They should be located at roof level.

Mauerlat

The Mauerlat is the base on which the load is applied, therefore it is from this that the construction of the rafter system begins. The location of this element is carried out in such a way as to evenly distribute the load from each support. This element of the rafter system is a log or beam that is laid on external walls. This option for creating a rafter system is the most effective.

Important ! To prevent moisture from getting on the Mauerlat reducing its service life, two layers of roofing felt are laid under the timber.

A beam with a cross-section of 10x15 cm is used as a mauerlat. This element is laid after the construction of the walls has been completed. After laying before fastening, the horizontal is determined using building level. The most popular fastening method is the use of anchor bolts.

The bolts are fixed to reinforced belt during the completion of the wall construction. After this, holes are drilled in the beam that coincide with the location of the bolts.

Types of rafters

Before building a rafter system, it is necessary to determine the type of rafters used. They are divided into 2 types:

• on the side;
• hanging.

If the structure is small, only simple rafters are used, which are attached to the mauerlat and connected to each other by lathing. If the structure is large (for example, a residential building), then more complex design roofs. Before installing the rafters gable roof With your own hands, you select the slope, which is determined based on the expected load from snow and wind.

Hanging rafters are a structure that is supported in only two places. This means that with this scheme, intermediate supports are not used. Distinctive feature This type of rafters is to create a bursting load on the walls of the building. This type of frame is most often used in construction residential buildings. If the roof slope angle is less than 45 degrees, then additional elements are installed. Most often, ties are used to connect the rafters to each other.

Important ! The higher the tension, the stronger it should be.

To construct a layered rafter system, a third support is required, which is usually another load-bearing wall.

Preparing for installation

Before starting work, you should prepare necessary tools And Consumables. To avoid dangerous situations, it is better to build scaffolding near the house. Don’t forget about individual insurance.

To work you will need:

• timber, the cross-section of which is 15X15 cm;
• waterproofing material;
• an adjustable wrench, which will be needed when tightening the anchor bolts;
• building level;
• hammer;
• drill;
• nails.

For the rafters, a beam is selected whose cross-section is 50X200 mm

Installation stages

Installation of gable roof rafters is as follows:

• lifting the timber onto the roof;
• sawing out part of the lower ends rafter legs in such a way that upon contact with the Mauerlat a reliable connection is formed;
• connection of paired rafter legs;
• installation of the outer rafters and connecting them using a ridge girder.

In order for the rafter legs to be connected to each other more securely, half of their thickness is cut out at the place where they are connected. Cutting out parts of the rafters takes place on the ground, since it is inconvenient to do this on the roof.

Before installing the rafters, the Mauerlat is marked in order to maintain the selected spacing between the supports. Usually the distance between them is one meter. The same marks are applied to the ridge run.

Methods for installing rafter legs on walls

If the rafters are installed on brick walls, they are secured using a device called a “ruff”. It is a metal element that is driven into the wall from inside the building and loops around the rafters.

On all structures that do not shrink, fastening occurs by cutting out a recess in the rafters for attachment to the Mauerlat. Attachment occurs using nails or corners.

Important ! There must be a distance of at least 130 mm between the rafter system and the pipe.

Reinforcing rafter legs with additional elements

If the rafter system has already been created, but the owner of the house finds out that it is not adapted to the loads that will affect it, he needs to strengthen the rafters. This happens by inserting additional wooden beams, which are called supports. Attaching to the rafters occurs using metal clamps or toothed plates.

Strengthening can also occur when there is too much load in the middle of the rafters, which threatens to break the beam. To avoid this, additional overlays are created on the connection area with the support. The new part of the rafter system can be erected both above and below the old roof elements.

If the installation occurs higher, then in addition to strengthening the roof, the slope also changes. This method avoids wasting time on complete replacement rafters and involves attaching new rafter legs to those already installed. The process of changing the roof begins with removing the sheathing. After this, new elements are installed, which in terms of the method of connection do not differ from the old rafter system.

In some cases, it is necessary to strengthen the bottom of the rafter leg. This is necessary in situations where the Mauerlat begins to rot and become less reliable. To strengthen the rafter legs, struts are attached, resting on the mauerlat or on an additional support. For more reliable fastening, notches are cut out on the rafters. Additional elements are attached using nails.

Ways to strengthen damaged structures

Methods for restoring damaged parts of the roof include:

• installation of wooden overlays;
• creation of rod prostheses;
• use of overlays resting on the beam.

The first method is used for single damage to rafter legs. To strengthen the element of the rafter system, wooden overlays are attached and secured with bolts or nails. Additional elements must rest securely against the Mauerlat and be secured in this position by twisting.

Rod prostheses are more often used in cases of massive damage to rafters. To strengthen, temporary supports are first installed so that the rafters are in a stationary position. After this, the damaged parts of the structure are cut out. Then the prosthesis is put on, which rests on the Mauerlat.

Overlays that rest on the beam are used when part of the Mauerlat has rotted. In this case, this area is cut out. To support the rafter leg, an additional reinforcing strut is created, which rests against a pre-fixed beam. The beam is located below the Mauerlat, if the wall structure allows it. In order to make a sheathing in a place where there is no longer support, an additional board is attached, onto which the sheathing is attached.

Unfortunately, you did not indicate which rafter system (hanging or layered) your parents used when constructing the roof. The mounting points for these systems are slightly different from each other. Let's look briefly at each of them.

Hanging The rafter system allows you not to lay the mauerlat when installing a cold (non-living) attic (you can save money on this). The lower part of the rafters is fastened to the tightening with a single or double tooth:

Plank tooth and steel plate tooth:

And at the top the rafters are connected to each other with bolts, metal plates or wooden plates:

At layered system, the rafter leg fits into the mauerlat and is secured with angles, nails or staples:

In the upper part, the rafters are attached to the ridge purlin with nails, bolts, wooden plates or metal plates without notches or with notches resting against the purlin:

All of the above mounting methods are quite reliable. When attaching rafter systems you need to adhere to the principle in which one end of the rafter leg has a sliding support (for hanging rafters this is the upper node) and when the magnitude of temporary loads changes (snow, wind), the structure does not crack. The other end of the rafters is fixed rigidly and has the ability to work with lateral loads (rotary mode).

The roof is top structural element structures that protect a wooden house from atmospheric influences. consists of rafter legs and sheathing. This system supports the roof, makes the installation of roofing much easier and is one of the most important structural elements of the house.

The durability and safety of the roof is ensured by proper arrangement of the attic ventilation system or a ventilated air layer in the attic roof, proper maintenance roofing, and, most importantly, it is necessary to carry out timely reinforcement or repair of rafters. Reasons for repair truss structure may depend on large snow loads, in which the rafters break, and, as a result, from prolonged wicking, they rot and collapse. The reasons for repairing rafters when rotting are explained by the fact that boards and beams from are used as the material for the rafter system in the construction of houses.

In our article we will look at options that allow us to strengthen the rafter structure, and we will also talk about ways to restore damaged and rotten rafter legs and sections of the mauerlat.

Strengthening the load-bearing truss structure using various options

In and rafter systems to increase bearing capacity rafter legs, several installation options are used. Strengthen the rafters with an additional wooden beam - help, double-sided overlays and installation struts, or arrangement of a board-and-nail farm.

The section of the rafter leg span between the rafter leg and the mauerlat beam, even with a cross-section of material suitable for the strength characteristics, may not pass the deflection calculation. IN in this case, the only solution in this situation is to increase the height of the rafter legs. Strengthening the rafters can also be done by including support in the beam. The role of support is performed by an additional wooden beam, with a cross-section selected for deflection calculations, including the height of the rafter section. The location of the help is in the gap between the rafter leg and the mauerlat (Fig.). The additional beam is attached to the rafter leg with jagged metal plates or bolted clamps.

The place where the continuous rafter leg rests on the strut is a rather dangerous node, where a fairly large bending moment can occur. When the bending moment increases by leaving dangerous situation there can only be an increase in the cross-section and height of the rafter leg. Another solution is to increase the width of the rafters. The width of the continuous rafter leg can be increased using double-sided board overlays(rice.). We select the width of the linings by calculating the total cross-section of the rafter beam for the maximum bending moment. The linings are attached to the beam on both sides with bolted clamps, bolts or nails.

When strengthening a rafter leg in two ways at the same time, for example, strengthening the rafter with help and double-sided plank overlays, it is recommended to increase the length of the rafter leg beam and move the edge of its support on the mow beyond the knot. The use of this design solution will solve not only the strengthening of the deflection point in the span, but also the strengthening of the support unit.

Often, under various circumstances, there is a need to reconstruct the roof to a steeper slope. In this case, the installation of new rafter legs is done by merging them with a cross wall of boards using nails with the old rafter system, if the integrity and safety of the old rafters allows this. New rafters are introduced into the structure below or on top of the old rafters. This creates board and nail truss(Fig.), which provides a new roof slope angle and increases the rigidity of the rafter system.

The method of strengthening the truss structure discussed above speeds up the work process due to the fact that the old roof does not need to be dismantled. At the same time, the under-roof space does not increase, and if the purpose of changing the roof slope angle was, then we will not get additional volume.

Methods for restoring damaged truss structures

Often, strengthening the truss structure involves timely repair of the rafters. The reasons for repairing a rafter structure arise when the end of the rafter leg rots. Wood rot can occur due to the use of raw material for beams or in the absence of properly equipped ventilation in a cold attic space. Rotting of the mauerlat or the ends of the rafter legs can also occur due to the lack of attic vents.

With sufficient ventilation and adequate insulation of the attic, damage to air vents and vapor barriers in the structure may occur. attic room. main reason Rotting of rafter legs and mauerlat is hidden in a leak in the roof or in the absence of a waterproofing layer between the wall masonry and the wood, where moisture in the wood often occurs from the masonry.

In this case, when the end of the rafter leg rots, the support unit for the beam on the mauerlat loses its reliability and reinforcement of the rafters at the support unit is required. The problem can be solved using the attachment method additional strut to the lower end of the rafter leg, and rest it against the same Mauerlat beam (Fig.). Additional struts are fastened using nails and resting on the rafters in the grooves.

Additional stability can be given to the rafter beam by extending the lower ends of the additional struts. If the reinforcing struts are rested against an additional support, it becomes possible to partially reduce the deflection of the rafter leg in the span between the mauerlat and the rafter leg.

Damaged areas of the structure can be restored and strengthened using several methods, which we will consider below.

For example, repairing the unit that supports the rafter leg on the mauerlat can be done using wooden plates that rest on the mauerlat with its end. Note that this method is used only in case of a single damage to the rafter beam with subsequent installation of twisted wire.

Repair of the rafter leg can be done using bar prostheses (Fig.). Advantage this method is to be used in case of massive damage to the rafter beam. Repair of rafters using bar prostheses begins with securing the rafter beam to temporary supports. Next, the damaged part of the rafters must be cut out; to do this, you need to disassemble part of the roofing. Rod prosthesis is put on the rafter beam and rests on the mauerlat. The prosthesis must be provided with a support platform that prevents the rafter leg that rests on it from sliding. The braced lattice provides rigidity of compression of the upper belt of the prosthesis.

The reasons for repairing a rafter structure are often damage to the end of the rafter leg and rotting of the section of the mauerlat on which the rafter beam rests. In such a situation, you can use pads resting on the beam (Fig.). To begin with, we will fix the rafter leg on temporary supports and cut out the damaged areas of the Mauerlat and the rafter leg. Next, we will hammer the crutches into the masonry and lay a meter-long beam on them. A one-meter-long bench can be laid on the ceiling or directly on the wall, if the structure of the ceiling or walls allows this. On both sides of the rafter leg we strengthen the reinforcing strut with nails and rest it against the laid beam. To support the sheathing, we will make a new elongated filly.

Ensuring a normal air exchange process in the attic floor is one of the most important points to preserve the wood of the wooden roof structure. If there is insufficient air exchange in attic Fungal spores develop and, as a result, wood rots. To restore ventilation, a number of measures must be taken (Fig.).

It is worth knowing that the cross-sectional area of ​​vents and dormer windows should be from 1/300 to 1/500 of the area of ​​the entire attic floor. The width of the vents should not exceed 2.5 cm. Having studied the nature of the movement of air flows in the room and determined the air temperature at the boundary of the insulation, there may be a need for additional dormer windows and vents. Note that at the upper limit of the insulation, the air temperature should not exceed two degrees, regardless of the level of negative outside air temperature.

It may be necessary to increase the thickness of the insulation layer. To do this, it is worth measuring it; maybe it will be enough to simply loosen the caked insulation (this must be done once every five years). The problem with insufficient air exchange may also be hidden in a damaged vapor barrier located under a layer of insulation; to do this, it simply needs to be restored.

It is worth adding that people who decide to build a log house may be confused by the brick wall in the images. Don’t worry, it doesn’t play any role here, since the rafter system is the same, both in brick and in wooden house. Your task is to familiarize yourself with how to repair it, and in this article we tried to provide comprehensive information. Use it and everything will be fine. But besides this, you can also familiarize yourself with other materials on our site.

The tempting simplicity of a roof with a single slope inspires thoughts of the opportunity to prove oneself in the field of a successful builder. The construction of a simple structure consists of simply laying rafter legs on supporting walls. None complex nodes, tricky and numerous connections.

However, even in the simplest carpentry there are tricks that require thorough study. The future performer needs to know exactly how the stops are attached pitched roof to prevent deformation and damage to the elements of the frame system.

Scheme rafter frame a pitched roof is extremely simple. It is a series of parallel laid boards or beams, resting their edges on two walls of different heights. For installation and fastening of rafter legs to building structure a transition element made of wood is used.

Depending on the type of box being installed and the wall material, the function of the transition element is performed by:

• Mauerlat. In a shed roof scheme, these are two separately laid wooden beams that complete concrete or brick walls.
• Upper harness frame structure. A belt made of double stitched boards or timber installed on top of the frame posts.
• The upper crown of the foot, made of timber or logs.

The rafter legs and the elements in contact with them are made of wood, which has the property of changing own sizes following fluctuations in background humidity and temperature changes. Spring and autumn time, especially in the rainy season, the length of the rafter legs will be slightly longer than in dry summers and frosty winters.

Imagine what will happen if the rafters, rigidly fixed at the top and bottom, increase in size. Gaps will appear in the waterproofing, fasteners will become loose, slate sheets will move, or shift. In addition, deflection and heaving of the roof frame will certainly affect its wear resistance.

However, changes linear dimensions rafters are not at all the main problem with wooden rafter systems. An unpleasant surprise, if not taken into account, will be the settlement of the newly built box.

It is most pronounced in wooden walls, but it is also very typical for structures made of concrete and brick. Remember that pitched roofs rest on the walls different heights. Without calculations, you can understand that they will sag by different sizes. Those. there is a threat that, due to the difference in the subsidence of the walls, the new roof will not simply change the angle of the slope. There will be a possibility of disruption of nodes with extremely negative destructive consequences.

Despite the simplicity of pitched roofs and the close-to-horizontal direction of laying the rafters, the listed risks should not be forgotten. The nodes used to fasten the rafter legs of a pitched roof must take into account the “whims” of the wood.

The work of the developer of his own pitched roof project is to find the right solution to three important problems, according to which:

• It must be possible to move the wooden parts relative to each other.
• All possible causes of connection failure should be excluded.
• It is necessary to provide the rafters with the opportunity to adapt to the consequences of wall subsidence so that they can take a stable position.

The rafter legs of shed roofs erected over walls of equal height are classified as layered. Hanging type is used if the box being equipped has walls of equal height, and the slope is formed by rafter triangles.

Everything is clear about fastening the triangles: with the horizontal side they are installed on the harness or Mauerlat, they have a maximum joining area with the supporting elements, and are fixed in the usual way.

With layered rafter legs, everything is much more complicated. They are installed at an angle to the supporting elements. Without processing and preparation for installation, the rafters have only two unreliable points of contact with the strapping or Mauerlat.

No matter how powerful the fastener is, two points are not enough to firmly seat the part. Even with a slight impact, such a slope will simply slide down along with the continuous sheathing and multilayer sheathing. However, there are methods invented by ancient builders to avoid such troubles.

In order to prevent unwanted movements, the contact area between the rafters and the supporting element is increased, for this purpose the following is done:

• Selection of cuts. These are cuts in the shape of a triangle or a triangle with a tooth. They are cut exclusively on the rafters, so as not to weaken the supporting mauerlat.
• The top or bottom edge of the rafter leg is filed down, thereby creating a support platform that increases stability. Performed strictly vertically or horizontally.

Depending on the type and location of sawing or trimming, notches and cuts may or may not limit movement wooden part. The restrictions are considered relative, because there are no absolutely rigid fastenings in the construction of pitched roofs. Experts classify the units used by degrees of freedom: from one to four.

In the construction of roofs with one slope, the following most often appear:

• Fastening nodes with one degree of freedom are practically stationary connections that allow the rafter to rotate slightly around the fastening point.
• Fastening units with two degrees of freedom are connections that provide the ability to rotate around the fastener and cause slight horizontal displacement.
• Fastening units with three degrees of freedom are connections that allow rotation and displacement horizontally and vertically.

The presence of degrees of freedom does not mean that the rafter will be able to rotate and move freely in the area of ​​the node. They are fastened quite rigidly, because they have to hold the sheathing, or another type of covering, or snow cover.

The connection will only show its capabilities if the load is exceeded. Then the rafter legs will just move and take a new position, and the system will remain without damage.

Any diagram of a pitched roof clearly shows us the presence of at least two connecting nodes. Let's divide them conditionally into upper and lower. In construction rafter roofs The rule applies: if one of the nodes is rigidly fixed, then the second should have more opportunities for movement.

Projecting and simplifying the technological principle, we can say: if the fastenings in the upper nodes of a pitched roof are made rigidly, then the lower connections must be freer to ensure the possibility of displacement when the pressure is exceeded. And vice versa: if the lower mount is practically motionless, then the rafter at the top needs to be provided with some reserve for movement and rotation.

After getting acquainted with the theoretical side of the issue of fastening the rafters of a pitched roof, you can begin practical research on the popular nodal schemes. Note that most projects of systems with a single slope are designed for the installation of rafters that form overhangs due to their own length. However, when covering large spans, it happens that the standard dimensions of lumber are not enough. In these cases, fillets are sewn to the rafters, creating an overhang. They are installed on the side of the installed leg and do not affect the principle of knot formation at all.

The second reason for using fillies in the formation of overhangs is that the rafters are too heavy, which is very difficult to lift and install. The third prerequisite lies in the features of the nodal fastenings: if the lower heel is installed on a slider with a trimmed edge.

No. 1: Support at the top and articulated bottom

A scheme with a rigidly fixed top and a relatively movable bottom is used in the construction of roofs over extensions, in the construction of objects with a steep roof and a significant difference between the heights of the supporting walls.

Simply put, where the top edge of the rafter rests on wooden beam, the purlin or wall of the main building and there is no space left for her to move. The lower node in such situations is calculated on a slider, allowing it to move slightly.

Algorithm classic version with the top resting on the purlin:

• We install the supports of the purlin frame. On the framing of the frame building on opposite sides we install supports sewn from three pieces of 25×100 boards. The middle segment should be 75mm shorter than the outer ones in order to form a kind of recess.
• We build a purlin frame. We place a 25×150 board of the required length into the recess.
• We apply a 25×100 board of arbitrary length to the end of the future roof, but approximately 30 cm longer than the diagonal drawn from the top of the purlin to the frame. We mark the vertical line of the upper cut, outlining the adjacent edge of the purlin. We mark the line of the bottom cut and the vertical for trimming the edge of the rafter.
• We cut out the rafter according to the marks, try it on after the fact, and, if necessary, adjust the cuts.
• According to the template we made, we cut out and install the rafter legs.

We select the type of fastener based on the expected load. It is more convenient to fix the top with corners, the bottom with corners, screwing no more than three screws into them, or with sliding supports. If necessary, the lower knot can be stabilized by sewing a support block to the rafter leg from below.

The connection point with the purlin can be designed slightly differently: the rafter is laid on the beam using a notch. Here the groove is selected strictly according to the size of the material. But if it is necessary to increase the degree of freedom, the horizontal wall of the notch is beveled at a slight angle, and the lower unit is equipped with a sewing strip.

No. 2: Top and bottom are articulated and fixed

The scheme is applicable when arranging boxes whose walls have already undergone intensive shrinkage. Suitable for isolated objects. The upper knot is made in the form of a triangular notch, the lower one is in the form of a cut with a tooth resting on the Mauerlat.

The process of constructing a lean-to rafter system:

• We install the blank board edgewise on the mauerlat bars anywhere on the roof.
• We lay a well-trimmed piece of board flat on the lower Mauerlat. We place it so that the outer edge coincides with the inner edge of the Mauerlat. Having outlined the scrap, we get an outline of the lower attachment point.
• We transfer the trim to the area of ​​the upper notch and outline it, because the lower heel of the rafter will decrease exactly by this amount.
• The blank with the nodes drawn and then sawn will serve as a template. Using it, we produce the number of legs specified by the project.
• We install the rafters. We fix them at the bottom with staples or pins, and at the top with corners.

If you need to increase the degree of freedom, by analogy with the previous method, the vertical edge of the upper notch will need to be slightly beveled. The cutting angle will then be not 90º, but 95 – 97º. Experienced carpenters make simple cuts directly on site, turning the workpiece upside down. Beginning performers should not imitate in the first stages.

The rafter template is used in roof construction only when there is no doubt about the geometric characteristics of the frame. In opposite situations, the rafters are tried on and made individually. First, the outermost elements of the system are installed, then the row legs along the cord stretched between them.

One of the variations on the theme of two hinged-fixed units involves the installation of a vertical cut at the top and a notch with a tooth at the bottom. Work on their installation is carried out as follows:

• We install the blank board on the mauerlat so that its lower corner is directly above the outer edge of the beam.
• At the top, using a piece of board, mark a vertical line (x) and measure its length.
• We transfer the length of the upper cut to the area of ​​the lower node. We set aside the length of the cut (x) vertically from the inner upper edge of the mauerlat.
• From the resulting point we draw a horizontal line. The result is a notch with a tooth.
• We cut out the nodes according to the marks, install them in place, fasten them with corners, duplicate the lower nodes with staples.

As the size (x) increases, the roof slope will increase, and as it decreases, it will decrease.

No. 3: Free top and hinged-fixed bottom

An ideal scheme for constructing a pitched roof with rafters, the edges of which extend beyond the walls. After some adjustments it can be used in the arrangement of extensions.

• We install the workpiece edgewise on the upper and lower mauerlat beams with the edges moving beyond the walls. Here you need an assistant to hold the board up.
• We apply a template - a trimmed piece of board sequentially to the lower and upper mauerlat so that the outer edge of the template coincides with the outer edge of the beams. We mark the lines of the upcoming cuts.
• We select cuts according to the outlined lines. We slightly bevel the vertical wall of the upper notch.
• We install the rafter, fix it at the top with nails or corners, and at the bottom with staples.
• We manufacture and install the remaining rafters in the same way.

It is clear that mobility and its antagonist are relative concepts. However, one cannot treat them with lukewarmness. It is necessary to take into account the degree of freedom of the node both during the design period and when choosing fasteners. Lack of structural mobility will lead to deformation, excess will contribute to instability.

No. 4: Mobility of both attachment points

A scheme with two moving units can be used if both fastening connections have no more than two degrees of freedom. Those. horizontal mixing is prevented by restrictive devices installed at the top and bottom.

Let's consider an example in which the rafters of the extension are laid at the top into niches cut out in the wall. This means that horizontal displacement is excluded, rotation and some vertical movement are possible. The bottom is planted using notches, but is limited in the horizontal direction metal corners.

Step-by-step actions of the builder of a single-slope building:

• We are preparing the object for work. On brick wall In the extension we install a mauerlat made of 100×150 timber. We lay it on the wide side closer to the inner edge of the wall. We fasten with anchors every 80cm. In the main wall of the building at the designed height, we cut out grooves for the upper heels of the rafters. The depth of the cuts is 12 cm, the step between them is 70 cm. If you don't want to bother with gouging, you can use metal brackets screwed to the wall.
• Making a template for the rafter leg. Place the blank board with its upper edge in the groove and the lower edge on the mauerlat. Stepping away from bottom corners blanks 10 cm in the horizontal direction, draw two triangular notches.
• According to the indications of the template, we make rafters. We install them, fixing the position with metal corners.

The device method is valid when covering spans up to 4.5 m. If you need to cover a larger span, the rafters will need a support group consisting of struts.

No. 5: Rigid attachment to an inclined harness

The method is used in frame construction, because the supporting element can only be laid at an angle on racks sawn at an angle. Either the racks of the frame itself or the cantilever-girder structure installed on the box are sawed down at an angle. In principle, the latter option is quite suitable for constructing a pitched roof over concrete and brick walls.

Stages of installing a pitched roof using an inclined frame:

• We assemble a structure that creates a roof slope. On the gable side of the frame building we install short posts with the top edge sawn at an angle.
• On the sloping top of the racks we lay the board in one row for small outbuildings, two for more serious houses.
• We equip the end sides of the roof with frames in the shape of a right triangle, the hypotenuse of which should follow the line of the slope.
• We apply the rafter to the end of the roof to mark the line of the bottom gash.
• We make according to the template required number rafter legs. We install them on the harness, fixing the position of the elements with metal corners.

Without a shadow of a doubt, we classify the last method as the simplest category. Of all the methods of attaching rafters to the frame and beams of the Mauerlat of a pitched roof, this is the most conducive to attempts at independent implementation.

Final fastening work

After installing the entire row of rafter legs, we check the design position of the elements and the distances between them. We apply an arbitrary board flat to the frame of the ramp, identify shortcomings and correct the flaws. Then we fasten the rafters with staples or ties to the walls one at a time in regions with medium and low wind activity. We fix each leg in areas with high wind load.

The fillies, if they are planned for installation, are made of material with dimensions half smaller than the dimensions of the rafter legs. Sew them to the side of the rafter. The length of the sewn area is on average 60-80cm.

Video to visually study the process

The presented methods and schemes for fastening the rafters of a pitched roof have been tested in practice. They are most often used in " pure form" However, some adjustments according to specific technical specifications are not excluded.

According to statistics, every second homeowner built his own home. According to their reviews, erecting a roof yourself is one of the most difficult stages for non-professional builders. Therefore, it is very important to approach this stage with a complete understanding of all the nuances of the process. To understand how to make a roof with your own hands, you need to study the device, installation technology, work order and features of fastening all components of the structure.

Types of roofs

First you need to decide on the form. To date, the most popular types are:

Features of forms

Covering the roof with one single slope will save nerves and materials, since structurally this is the simplest option. If you make such a frame yourself, the labor intensity of the work will be minimal and the installation speed will be high. But this form has a drawback - there is no possibility of arranging a full-fledged attic or attic, since the under-roof space is too low.

A gable roof is installed much more often. It is a little more difficult to manufacture, but allows you to get more space. Compared to the hipped one, it has less complexity and mass, but it will be necessary to make triangular pediments at the ends of the building.

Gable - the most popular form

Before you start self-construction roofs with four slopes will require serious preparation. This system has more elements compared to the previous two. In addition, it is not possible to make full-fledged windows in the attic, since the roof structure does not have gables and installation is difficult or cannot be avoided.

The hipped roof is complex in design, but savings are achieved due to the absence of gables

For the attic excellent option there will be a combined design with . In this case, the lower part of the roof has a greater slope than the upper section. This assembly allows you to raise the ceiling in the room and make the constructed house more comfortable.

Broken line - not the most “architectural”, but very effective in terms of space used

Calculation

Before starting work, you need to make a design calculation. It makes no sense to calculate the cross sections of all elements. In most cases they can be accepted constructively:

• Mauerlat - 150x150 mm;
• racks - 100x150 or 100x100 mm depending on the cross-section of the rafters;
• struts - 100x150 or 50x150 mm, taking into account ease of connection with the rafters;
• puffs - 50x150 mm on both sides;
• purlins - 100x150 or 150x50 mm;
• overlays with thickness from 32 to 50 mm.

Calculations are usually performed only for rafter and slope legs. It is necessary to select the height and width of the section. The parameters depend on:

• roofing material;
• snow area;
• pitch of rafters (selected so that it is convenient to lay insulation, for mineral wool there should be 58 cm of clearance between the elements);
• span.

You can select the cross-section of the rafters using general recommendations. But in this case it is recommended to make a small reserve.

The calculation is usually performed for rafter legs

If you don’t want to delve into the intricacies of calculations, you can use special ones.

If you are planning to do warm roof, then the height of the cross-section of the legs is selected taking into account the thickness of the insulation. It must be mounted so that it does not protrude higher load-bearing beams. You also need to take into account that for mineral wool a ventilation gap of 2-4 cm is made between it and the coating. If the height of the rafters is not enough for this, provision is made for installing a counter-lattice (counter battens).

Step-by-step instructions for performing the work

The sequence of stages of roof construction is as follows:

1. taking measurements of the building box (dimensions may slightly differ from the design ones);
2. preparation of materials and tools, treatment of wood with antiseptic;
3. fastening the Mauerlat to the wall;
4. installation of a ridge crossbar, if needed (for layered rafters);
5. frame installation;
6. strengthening the roof using racks, struts and tie-downs;
7. waterproofing;
8. sheathing;
9. providing ventilation;
10. installation of drips;
11. installation of coating.

Fastening the Mauerlat

In order for the roof to be securely fastened, you need to take care of it reliable connection with the wall of the building. If a wooden house is being built, then the Mauerlat is not required - this element is the upper crown made of timber or logs. In this case, fastening to the wall is carried out using special “floating” fasteners. They are sold ready-made, most often called sleds. This type of roof arrangement allows the entire structure to shift slightly as the walls shrink without destruction or deformation.

“Sliding” fastening in a wooden house

A similar situation arises with a frame house. In this case, the Mauerlat will be top harness walls It is attached to the frame posts with a gash using angles, staples or nails.

Methods for attaching rafters to the frame in frame house

The roof structure made of brick, concrete blocks or concrete involves fastening through a Mauerlat. In this case, there are several ways.

There are four ways to place the Mauerlat on the wall:

• on staples;
• on stiletto heels;
• on anchor bolts.

The Mauerlat can be secured to brackets. In this case, in the masonry with inside pawn wooden blocks. They should be located at a distance of 4 rows from the edge. One side of the bracket is attached to the mauerlat, and the other to the same block in the masonry. The method can also be considered simple. It is not recommended for large buildings with high loads.

Fastening the Mauerlat to brackets. Antiseptic wooden blocks are provided in the masonry of the wall with a pitch of 1-1.5 m

When installing the roof yourself, fastening can be done through studs or anchor bolts with a diameter of 10-12 mm. The fasteners are laid in the masonry. The Mauerlat is temporarily placed on the sawn-off edge and lightly hit with a hammer. After this, indentations remain on the beam at the fastening points. You need to make holes for the studs along them. After this, the beam is put on the fasteners and the nuts are tightened. The method is ideal for walls made of lightweight concrete with a monolithic reinforced belt.

Attaching the rafters to the mauerlat

In houses made of brick or stone, it is more reasonable to perform it using rigid fastening of the rafters to the mauerlat. In this case, you can use both layered and hanging system. The design involves two methods:

• with notch;
• without cutting.

In the first case, the rafters are cut with a slope so that they are tightly adjacent to the mauerlat. To remove the cornice, fillies are provided. They are attached to the leg with an overlap of at least 1 m. Rigid fixation of the assembly should be done using self-tapping screws, nails or staples. But the assembled frame will be more reliable if metal corners with holes for self-tapping screws are used for fixation.

The method without cutting often does not involve the use of fillies. In this case, the beams themselves provide the frame extension. This option is simpler than the previous one, since it does not require high precision. It is suitable for beginners. In this case, stop bars or boards are used to ensure a tight fit to the Mauerlat. Rigid fixation, as in the previous case, is performed with metal corners on both sides.

Attaching rafters to the wall

The completed frame must be secured to the frame of the building - this will prevent a strong gust of wind from tearing off the roof. To do this, the rule is to use a twist of two wires with a diameter of 4 mm. They are wrapped around the leg where it rests on the mauerlat, and then the wire is attached to the wall with an anchor or ruff about 4-5 rows before the cut. The element must be laid in the masonry in advance.

Wind protection

For wooden house you can simplify the task. You can assemble the frame using staples. This option will speed up the process. But it is important to remember that this method is only suitable if the walls are made of wood.

Strengthening the system

How to strengthen the frame for spans of more than 6 meters? It is necessary to reduce the free span of the rafters. For this purpose, struts and racks are used. Reinforcement must be done taking into account the layout; it is important that these elements do not interfere with people’s stay and fit harmoniously into the interior.

The struts are usually placed at an angle of 45 or 60 degrees to the horizontal plane. The racks cannot be supported on the floor span. They can be installed on underlying walls or beams and trusses thrown between walls.

Tightening is necessary to reduce the thrust. Because of it, the rafters can simply move apart. This is especially true for systems with hanging beams. To assemble the frame, use two ties, which are attached on both sides of the rafters. Fixation is carried out using screws, nails or studs.

At the top point, the rafters rest on an intermediate or ridge girder. Depending on the chosen system, location and width of the span, it is made of timber with a cross-section from 50x100 to 100x200 mm. Fastening is carried out on connecting metal plates, bolts or nails.

Lathing

Before starting work at this stage, it is necessary to lay waterproofing material. Builders recommend using a vapor diffusion moisture-proof membrane. It costs more than polyethylene film, but guarantees more reliable protection. Owning your own home is not a reason to save money.

The roof requires fastening of the sheathing. The type depends on the selected roofing material. For metal, a sparse sheathing of boards 32-40 mm thick will be sufficient. Under bitumen shingles needed continuous lathing from 25-32 mm boards or moisture-resistant plywood.

Ventilation of the under-roof space

Before proceeding with the roofing stage, it is worth considering the ventilation of the under-roof space. This will protect structures from mold, mildew and destruction.

Correct arrangement ventilation under the roof will protect the structure from the appearance of fungus

For ventilation it is necessary to provide:

• air flow through the cornice (the cornice is hemmed with a sparse board or special perforated soffits);
• air movement under the coating (there should be a gap of 2-3 cm between the insulation and the roof);
• air outlet in the area of ​​the ridge (for this, a ridge and/or point aerator is installed on the roof).

Roof covering

The type of roof is selected for aesthetic and economic reasons. It is also worth studying the manufacturers’ proposals and finding out the permissible slope. For example, it is not recommended to lay bitumen shingles on a slope of more than 45°.

Seam roofing is a lightweight fireproof and durable coating

The flooring material must provide reliable waterproofing. Its installation is carried out in strict accordance with the manufacturer's instructions. There are five most common types of coverage: roof insulation.

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