A roof with two slopes is the most common option for completing the box of a private house. In its manufacture, it is important to correctly select the cross-sections of the supporting elements, securely fasten the nodes and choose the right type of construction. truss system gable roof does not have great difficulties and may well be made by hand.

Classification of truss systems according to the method of support

The structure can be classified in two ways. The first of them is the method of supporting the bearing elements. The gable roof truss system of the house in this case includes the following types:

• with layered rafters;
• with hanging rafters.

Types of a gable roof with layered and hanging rafters

Roofing with the use of layered rafters involves their support at two points. The design in this case avoids the occurrence of a serious spacer. To do the installation yourself, you will need the following basic elements:

• rafter legs;
• Mauerlat;
• crossbar;
• intermediate racks and struts with a large span of load-bearing beams;
• crate and counter-crate;
• overlays persistent bars.

At the top point, the installation provides for leaning on the crossbar. The installation also provides support at the lowest point - Mauerlat. You can assemble such a structure for a house with your own hands only in two cases:

Options for assembling a layered gable roof system

1. A layered system is possible if the distance between the gables is not large. That is, such an installation is suitable for small house with your own hands. The greatest length of the structure, which allows the construction of a wooden crossbar without additional reinforcements, is 6 m. For large spans, it will be necessary to install metal beams. Using wooden beam it will be necessary to provide intermediate racks, which are located on average after 2 meters. This can be avoided only when using glued laminated timber of a sufficiently large cross section as a crossbar. In this case, a free layout of the space becomes impossible - the racks in the middle of the room cannot be removed.
2. The second option, when it is possible to install a layered gable roof system with your own hands, is the presence of a wall in the middle of the house. The device in this case provides that the beam, on which the rafters will rest at the top point, will transfer the load to the inner wall. In this case, the supporting structure should not be confused with the partition. The partition rests on the floors, and installing the wall of the house with your own hands involves resting it directly on the foundations. Such a device is suitable for buildings with sufficient width, where it makes sense to install a wall fence in the middle.

The second option is hanging rafters. They are more complex in calculation, but they allow the installation in the under-roof space of a free-plan house. The design assumes the absence of a supporting wooden or metal bar in the upper part. Installation involves supporting the rafters only at the lowest point. In the upper part, the bearing beams are securely connected to each other. Installing such a system is like a farm. The design works on thrust, so it is important to prevent excessive horizontal load on the walls of the house. You can do this by doing the following:

• the device of a monolithic belt along the edge of the walls;
• it is necessary to make a reliable fastening of the Mauerlat of a gable roof to the wall of the house with your own hands;
• to eliminate the spacer, a contraction is established.

Installation of a hanging truss system

The fight or screed becomes one of the significant elements of the gable roof of the house. It prevents the expansion of the walls under the action of thrust. The following types of fights can be distinguished:

• located at the attic floor level;
• located at the level of the attic ceiling.

It is worth noting that the second option provides less reliability, since the higher the element is mounted, the stronger the rafters have an effect on it. If the fight turns out to be too long, you need to make it stronger with your own hands. For this, additional elements of the gable roof of the house are installed - suspensions. They connect the skate to the middle of the puff, which prevents it from sagging.

The gable roof truss system with hanging rafters allows installation with pre-assembly of trusses on the ground, then raise them to the roof and fix them.

This option is only suitable if you have lifting equipment, since the finished gable roofs of the house will become too large and heavy to lift with your own hands.

Classification by type of slope

The second division can be made depending on how the ramp line is designed. The views here suggest the presence of two options:

Gable roof with broken and straight slopes

1. With straight slopes. The easiest way to do. Allows you to get the job done without any hassle. The disadvantage of this do-it-yourself roofing option is the reduction in attic space.
2. With broken slopes. Such types of roofing are more difficult to perform. It is assumed that there is a line along which the angle of inclination changes. The angle of inclination of the lower part of the slope must be made greater than that of the upper. Thus, it turns out to raise the ceiling of the attic and increase the free space. The installation of the roof is carried out with the installation of an additional crossbar at the fracture site.

These types involve a choice between them, depending on the wishes of the future owner of the building.

The main elements of the roof

The rafter system of the gable final part of the building consists of many elements. Installation should begin with a detailed study of each of them and the choice of their sections.

When installing elements under a metal tile or other coating, it implies the use of a bar with a section of 150x150 or 200x200 mm. It is this size that allows you to most optimally distribute the load. then you need to choose a method of fixing it depends on the material of the walls. There are several options:

The scheme of fastening the Mauerlat to the wall

1. Frame, timber or log walls do not require the installation of a Mauerlat. In the case of a frame building, the top framing of the walls serves as a support for the rafter legs. during the construction of fences from timber or logs, the upper crown becomes the Mauerlat. It is important to correctly fix these elements in the wall structure.
2. When used for the construction of lightweight concrete, additional reinforcement will be required. TO lightweight concrete include materials such as foam concrete, slag concrete, expanded clay concrete. They can collapse if the roof is not supported centrally on them. To evenly distribute the load, a monolithic reinforced concrete belt is poured along the edge of the walls. During work, a special wire, studs or bolts are laid in it, on which the Mauerlat will be fastened.
3. For brick means, it is possible not to provide a reinforced concrete belt. In this case, to connect with the strapping beam, a wire is inserted into the masonry, which is then wrapped around the Mauerlat and twisted. The second option - one row before the walls are cut into masonry with outside give birth to wooden bars soaked in an antiseptic. Such plugs and Mauerlat are fastened with staples. It is also possible to use studs and bolts, for fixing which will require pouring a monolithic belt.

An important point is waterproofing.

When installing, it is important to provide roofing material, linokrom or waterproofing at the junction of concrete or brick with wood. This is required to prevent the wood from rotting on contact with material of a different moisture content.

After fixing the Mauerlat, rafter legs are installed. Their cross section is selected depending on the pitch of the supporting beams, their span, snow load and type of coating. When installing a frame under a metal tile with a step of 60 cm, it is recommended to follow the following recommendations, depending on the span:

• 3 m - 4x15 cm;
• 4 m - 5=15 cm;
• 5 m - 5x17.5 cm;
• 6 m - 5x20 cm.

Table of average values ​​of rafter legs

These are average values, in order to perform a more accurate calculation, it is better to contact a specialist or study additional literature.

There are two ways to fasten the rafter legs to the Mauerlat:

• with a notch;
• without her.

Fastening rafter legs to the Mauerlat with and without a notch

In the first case, they washed down on strapping beam, in the second, a special board is nailed to the rafters, which becomes a stubborn bar. Further, for both methods, the work is performed in the same way. With the help of metal corners, the inclined beam is fixed so that it does not move relative to the design position along the Mauerlat. Additionally, nails are driven in at an angle.

Scheme of fastening rafters with wire and brackets

In addition, you will need to fasten the rafter to the wall. This action is envisaged in normative documents. You can do this in two ways:

• on brackets (suitable for wooden buildings);
• using wire twisting (a more time-consuming option, but the only one possible for stone houses).

You can perform fastening according to the norms through one leg. This is necessary for a more secure attachment of the roof to the box of the house.

If you do the work correctly, you can not worry about its condition even in the strongest winds.

Racks, ties, struts

Such elements are most often made of boards. The optimal thickness is in the range of 32-50 mm. Racks are an exception. Here you can use boards with a thickness of 50-100 mm. Fastening is carried out on studs or using support bars.

Gable roof truss system: design and nodes

A gable roof is the most common in construction. For proper installation, it is recommended to study the device of the gable roof truss system.

The device of the truss system of a gable roof

The gable roof truss system is designed for roofing in the form of two rectangles located at a certain angle to each other in the upper part of the structure. This design is often used in the construction of private low-rise buildings, various buildings for domestic and household purposes. At industrial and commercial enterprises, a gable roof is installed on buildings for various purposes, which have a significant length several times greater than the width. The design contains two slopes of different lengths. On the front side, a short slope with a large angle of inclination is installed, on the back - a long one, with a smaller angle of inclination. This configuration allows the main part of atmospheric precipitation to be directed to the non-working zone of the enterprise territory.

Figure 1. Scheme of fillies.

The construction of a gable roof is one of the low-cost options that does not require significant physical effort.

It is performed relatively simply with little experience working with wood material.

Typical bearing elements of the system, specific terms

Figure 2. Scheme of the crate.

In the manufacture of details of the gable roof truss system, lumber is used conifers tree. Hardwood is undesirable due to its high specific gravity. Most of the elements have specific names that are understood mainly by specialists:

1. Lezhen - timber with a section of 150x150 mm, 180x180 mm. It is laid on the surface of the internal load-bearing wall. Designed for leveling the surface and distributing loads from racks.
2. The rafter leg, or rafter, is a piece of timber or thick board. The main element of the triangular roof structure, bearing the main load from snow, rain, wind and other atmospheric phenomena. The distance between the rafter legs can be from 0.6 to 1.2 m. The step size mainly depends on the plumb line of the roofing material, in some cases, the characteristics of the roofing material should be taken into account.
3. Mauerlat - a square beam with a side size of 150-180 cm. It is laid on the surface of external load-bearing walls. When installing, it must be fixed with anchor bolts or in another reliable way. Distributes the load from the rafter legs to the load-bearing walls.

All parts of a gable roof are interconnected in various ways. Previously, structures were assembled mainly using staples, nails, threaded studs. Now manufacturers of building materials offer a wide range of different brackets for assembling roofs of any configuration. Most parts are fastened with self-tapping screws of the required diameter and length, reinforced with special spikes in the brackets.

Additional elements of the rafter system

Figure 3. Scheme of an arch with three hinges.

In addition to load-bearing parts, additional reinforcing elements are used in the structures:

1. Filly (Fig. 1) - used to increase the length of the rafter legs. Are established in the lower part for the device of cornice overhang. The thickness of the fillies is somewhat smaller sizes rafters.
2. Roof overhang, or cornice overhang, is a roof element protruding from the edge of the wall by about 40-50 cm. Designed to protect walls from atmospheric precipitation.
3. The ridge is an element that connects all the rafter legs of the system in the upper part. Installed in a horizontal position.
4. Sheathing (Fig. 2) - boards or bars installed for fixing the roof. They are located perpendicular to the rafter legs, additionally performing the function of their fastening. They take the main effort from the roofing material, distribute it to the rafters. For the device, it is desirable to use edged lumber. With limited funds, you can use unedged, clearing it of bark. If the roof is soft material, the crate is made solid. This option can be made from boards or plywood treated with protective materials from high humidity. When corrugated board is used, the crate is performed with a certain step, depending on the weight of the material and its design features.
5. Struts - elements made of timber or thick boards that reinforce the main structure. Distribute the force from the rafter legs to the bearing parts. Assembled structure from struts and puffs, it was called a farm - an enlarged part with the necessary margin of safety.
6. Racks - are made from pieces of lumber of rectangular or square section. Are established in vertical position under a descent of slopes. The load from the corner connection of the roof rafters is distributed through the posts to the internal load-bearing wall.
7. Puff - a bar or board that fastens the rafters in a hanging system. Creates a rigid triangle shape between rafter legs, compensating for sprawl.

For the manufacture of additional parts, you can use lumber with a section similar to that of load-bearing parts. In order to save money, you can calculate and purchase products of a smaller section.

Two typical ways to arrange truss systems

Figure 4. Scheme of connecting the lower ends of the parts.

The gable roof truss system can be arranged in two main ways:

• hanging rafter system;
• layered system.

The hanging system is used for buildings with a distance between the outer walls of less than 10 m, without an internal load-bearing wall in the middle of the building. In a different configuration of the building, a layered rafter structure is used.

If the building has columns located along one of the central axes, it is possible to use combined option. Rafter legs located above the columns are mounted with emphasis on the surface of the columns, hanging rafters are installed between them.

Hanging truss system

In structures of this type, the installation of truss beams is carried out on the surface of the outer walls. The disadvantage of this method is the occurrence of force, bursting the walls. To compensate for the load, the beams are pulled together by tightening. The design takes the form of a rigid triangle that retains its shape under the influence of loads. In some cases, floor beams can play the role of puffs. Such a scheme is used when arranging an attic in the attic space.

Hanging rafters can be made in various versions:

Scheme of the reinforced structure.

1. A simple version of the arch with three hinges (Fig. 3) - the design is a rigid triangle, the two sides of which are the rafter legs. The main load creates a bending force on the parts. The force on the third side is aimed at stretching the structure, so instead of a wooden part, a steel tie can be used. The connection of the lower ends of the parts can be assembled different ways(Fig. 4), inserting beams into the puff, using wooden elements or metal brackets.
2. Reinforced structure (Fig. 5) - a gable truss system used for roofing of large industrial buildings with a distance between walls of more than 6 m. This system is not suitable for use in small residential buildings. A design feature is the distribution of the puff weight on the skate. Since it is almost impossible to find solid lumber of the required length (6 m or more), the puff is made from segments. The connection of all elements is carried out by a straight or oblique inset. The central part is called the headstock. The connection of the headstock with a tightening is performed by a collet twist with the possibility of adjusting the tension.
3. The device of an arch with a tightening in the upper part of the rafters (Fig. 6) is used for equipment in the attic space of the attic. At the same time, the tensile force in roof beams increases. The lower ends of the beams are attached to the Mauerlat bars. The fastening should limit the movement of the beams to the sides along the beam, but allow sliding across. This ensures uniform load distribution and stability of the entire system. Rafter beams should form an overhang.

Many variants of hanging-type systems have been developed. Most are used for relatively small buildings without load-bearing structures inside buildings. For buildings bigger size you need to use a system of rafters of a layered type.

Layered truss system

The main difference of this system is the installation of a vertical beam resting on an internal load-bearing wall located in the middle of the building. This design is necessary when a gable roof is installed on a building with a wall spacing of more than 10 m.

Figure 6. Arrangement of an arch with a puff at the top of the rafters.

1. A properly executed system of non-expanding rafter beams allows you to get rid of the forces that burst the walls. The surface of the slopes is subjected only to the bending force. There are 3 main options for the device of such systems. With all options, the lower ends of the rafters are attached according to the sliding support method. For insurance, an additional mount is installed between the support bar and the rafter leg.
2. You can use a steel strip, wire tie. The options differ in the method of connecting the upper ends of the rafters, docking with the ridge beam. One of the options involves laying rafters on a beam in the form of a sliding support with a cutout device. Mounting can be done using brackets or special brackets. The gable roof, arranged according to the following option, is the most popular because of the simplicity of the device. The top of the rafters can be made end-to-end or overlay with cutting grooves. The corner must be fastened with any of available ways and fix it on the skate beam. The third option involves a rigid connection of the run and rafters. For mounting on rafter legs, pieces of boards are stuffed on two sides. A large bending force is formed on the beam, but the load on the rafter beams is reduced.
3. A gable roof for a building with dimensions up to 14 m must have a reinforced truss system. One of the options for increasing strength is the installation of a strut. The part takes on the load from the rafter leg, experiencing a compressive force. To correctly select the installation position of the element, you need to measure the angle of 45-53 ° from the horizontal plane of the building. An additional support device turns an ordinary beam into a reinforced version, consisting of two spans. To install the struts, calculations are not required, you just need to fix it under the rafter, cutting out the joint angle with maximum accuracy.

The technology for installing gable roofs is simple, you can do everything yourself. Work must begin with the installation and fastening of the base to the walls, then mount the gables. It is desirable to carry out work on the manufacture of rafter beams and enlargement of structures on the ground, to lift the assembled elements, install them on the building, and fix them with temporary fasteners. After assembling and installing all the elements, you should fix the crate and proceed with the installation of the roof.

Gable roof truss system: installation and diagrams

The gable roof truss system is designed for roofing in the form of two rectangles located at a certain angle to each other in the upper part of the structure.

Do-it-yourself gable roof truss system: an overview of hanging and layered structures

Rafters perform a number of significant roofing functions. They set the configuration of the future roof, perceive atmospheric loads, and hold the material. Among the rafter duties are the formation of even planes for laying the coating and providing space for the components of the roofing pie. In order for such a valuable part of the roof to flawlessly cope with the listed tasks, information about the rules and principles of its construction is needed. The information is useful both for those who are constructing the gable roof truss system with their own hands, and for those who decide to resort to the services of a hired team of builders.

Rafter structures for gable roofs

In the device of the truss frame for pitched roofs, wooden and metal beams are used. The starting material for the first option is a board, log, beam. The second is constructed from rolled metal: a channel, a profile pipe, an I-beam, a corner. There are combined structures with steel most loaded parts and wood elements in less critical areas.

In addition to the "iron" strength, the metal has a lot of disadvantages. These include heat engineering qualities that do not satisfy the owners of residential buildings. Disappointing need to apply welded joints. Most often, industrial buildings are equipped with steel rafters, less often private change houses assembled from metal modules.

In the case of self-construction of truss structures for private houses, wood is a priority. It is easy to work with it, it is lighter, “warmer”, more attractive in terms of environmental criteria. In addition, nodal connections do not require a welding machine and welder skills.

Rafters - a fundamental element

The main "player" of the frame for the construction of the roof is the rafter, among the roofers called the rafter leg. Beds, braces, headstocks, girders, puffs, even Mauerlat may or may not be used depending on the architectural complexity and dimensions of the roof.

The rafters used in the construction of the gable roof frame are divided into:

• Layered rafter legs, both heels of which have reliable structural supports under them. The lower edge of the layered rafter rests on the Mauerlat or on the ceiling crown of the log house. The support for the upper edge can be a mirror analogue of an adjacent rafter or a run, which is a beam horizontally laid under the ridge. In the first case, the truss system is called spacer, in the second, non-spacer.
• hanging rafters, the top of which rests against each other, and the bottom is based on an additional beam - puff. The latter connects the two lower heels of adjacent rafter legs, resulting in a triangular module called a truss truss. The tightening dampens the tensile processes, so that only a vertically directed load acts on the walls. The design with hanging rafters, although it is spacer, does not transfer the spacer itself to the walls.

In accordance with the technological specifics of the rafter legs, the structures constructed from them are divided into layered and hanging. For structural stability, they are equipped with struts and additional racks. For the arrangement of supports for the top of the layered rafters, beds and girders are mounted. In reality, the truss structure is much more complicated than the elementary patterns described.

Note that the formation of a gable roof frame can generally be carried out without roof structure. In such situations, the alleged planes of the slopes are formed by slegs - beams laid directly on the bearing gables. However, we are now specifically interested in the device of the gable roof truss system, and it can involve either hanging or layered rafters, or a combination of both types.

Subtleties of fastening rafter legs

Fastening the truss system to brick, foam concrete, aerated concrete walls is made through the Mauerlat, which in turn is fixed with anchors. Between the Mauerlat, which is wooden frame, and with walls made of these materials, a waterproofing layer of roofing material, waterproofing, etc. is mandatory laid.

The top of brick walls is sometimes specially laid out so that outer perimeter it turned out something like a low parapet. So it is necessary that the Mauerlat placed inside the parapet and the walls do not burst the rafter legs.

Roof frame rafters wooden houses rest on the upper crown or on ceiling beams. The connection in all cases is made by cutting and duplicated with nails, bolts, metal or wooden plates.

How to do without furious calculations?

It is highly desirable that the cross section and linear dimensions of the wooden beams be determined by the project. The designer will give clear calculation justifications for the geometric parameters of the board or beam, taking into account the entire range of loads and weather conditions. If there is no home design development master at his disposal, his path lies on the construction site of a house with a similar roof structure.

You can ignore the number of storeys of the building under construction. It is easier and more correct to find out the required dimensions from the foreman than to find them out from the owners of a shaky unauthorized construction. After all, the foreman is in the hands of documentation with a clear calculation of the loads per 1 m² of roof in a particular region.

The installation step of the rafters determines the type and weight of the roofing. The heavier it is, the smaller the distance between the rafter legs should be. For styling clay tiles, for example, the optimal distance between the rafters will be 0.6-0.7 m, and for the installation of metal tiles and profiled sheets, 1.5-2.0 m is acceptable. However, even if the step required for the correct installation of the roof is exceeded, there is a way out. This is a reinforcing counter-lattice device. True, it will increase both the weight of the roof and the construction budget. Therefore, it is better to deal with the step of the rafters before the construction of the rafter system.

Craftsmen calculate the pitch of the rafters according to the design features of the building, tritely dividing the length of the ramp into equal distances. For insulated roofs, the step between the rafters is selected based on the width of the thermal insulation boards.

Rafter structures of layered type

Rafter structures of the layered type are much simpler in execution than their hanging counterparts. A justified plus of the layered scheme is to provide full ventilation, which is directly related to the longevity of the service.

Distinctive design features:

• Mandatory presence of support under the ridge heel of the rafter leg. The role of the support can be played by a run - a wooden beam resting on racks or on the inner wall of the building, or the upper end of an adjacent rafter.
• The use of Mauerlat for the construction of a truss structure on walls made of brick or artificial stone.
• The use of additional runs and racks where the rafter legs, due to the large size of the roof, require additional support points.

The minus of the scheme is the presence of structural elements that affect the layout inner space operated attic. If the attic is cold and organization is not supposed to be in it utility rooms, then the layered design of the truss system for the installation of a gable roof should be preferred.

A typical sequence of work on the construction of a layered truss structure:

• First of all, we measure the height of the building, the diagonals and the horizontalness of the upper cut of the skeleton. When identifying vertical deviations of brick and concrete walls, we eliminate them with a cement-sand screed. Exceeding the heights of the log house we squeeze. By placing chips under the Mauerlat, vertical flaws can be dealt with if their magnitude is insignificant.
• The floor surface for laying the bed must also be leveled. He, the Mauerlat and the run must be clearly horizontal, but the location of the listed elements in the same plane is not necessary.
• We process all wooden parts of the structure before installation with fire retardants and antiseptic preparations.
• on concrete and brick walls we lay waterproofing for the installation of a Mauerlat.
• We lay the Mauerlat beam on the walls, measure its diagonals. If necessary, we slightly move the bars and turn the corners, trying to achieve the perfect geometry. Align the frame horizontally if necessary.
• We mount the Mauerlat frame. The splicing of the beams into a single frame is carried out by means of oblique cuts, the joints are duplicated with bolts.
• We fix the position of the Mauerlat. Fasteners are made either with brackets to wooden plugs laid in the wall ahead of time, or with anchor bolts.
• We mark the position of the bed. Its axis should recede from the Mauerlat bars at equal distances on each side. If the run will be based only on racks without lying down, the marking procedure is carried out only for these columns.
• We install the bed on a two-layer waterproofing. We fasten it to the base with anchor bolts, with inner wall connect with wire twists or staples.
• We mark the installation points of the rafter legs.
• We cut out racks according to uniform sizes, because our bed is set to the horizon. The height of the racks must take into account the dimensions of the section of the run and the bed.
• Installing racks. If provided by the project, we fix them with spacers.
• We lay the run on the racks. We check the geometry again, then install the brackets, metal plates, wooden mounting plates.
• We install a trial rafter board, mark the places of trimming on it. If the Mauerlat is set strictly to the horizon, there is no need to adjust the roof rafters in fact. The first board can be used as a template for making the rest.
• We mark the installation points of the rafters. Folk craftsmen for marking usually prepare a pair of slats, the length of which is equal to the gap between the rafters.
• According to the markup, we install the rafter legs and fasten them first at the bottom to the Mauerlat, then at the top to the run to each other. Every second rafter is screwed to the Mauerlat with a wire bundle. In wooden houses, the rafters are screwed to the second crown from the top row.

If the rafter system is done flawlessly, the layered boards are mounted in random order. If there is no confidence in the ideal structure, then the extreme pairs of rafters are installed first. A control twine or fishing line is stretched between them, according to which the position of the newly installed rafters is adjusted.

The installation of the truss structure is completed by installing the filly, if the length of the rafter legs does not allow the formation of an overhang of the required length. By the way, for wooden buildings the overhang should “go beyond” the contour of the building by 50 cm. If the organization of the visor is planned, separate mini-rafters are installed under it.

Hanging truss systems

The hanging type of truss systems is a triangle. The two upper sides of the triangle are folded by a pair of rafters, and the puff connecting the lower heels serves as the base. The use of tightening allows you to neutralize the effect of the thrust, therefore, only the weight of the crate, the roof, plus, depending on the season, the weight of precipitation, acts on walls with hanging truss structures.

The specifics of hanging truss systems

Characteristic features of hanging type truss structures:

• Mandatory presence of a puff, made most often of wood, less often of metal.
• The ability to refuse the use of Mauerlat. A frame made of timber will be successfully replaced by a board laid on a two-layer waterproofing.
• Installation on the walls of ready-made closed triangles - roof trusses.

The advantages of the hanging scheme include the space under the roof free from racks, which allows you to organize an attic without pillars and partitions. There are disadvantages. The first of these is the limitation on the steepness of the slopes: their slope angle can be at least 1/6 of the span of a triangular truss, steeper roofs are strongly recommended. The second disadvantage is the need for thorough calculations for the competent device of cornice nodes.

Among other things, the angle of the truss truss will have to be set with jewelry accuracy, because. the axes of the connected components of the hanging truss system must intersect at a point, the projection of which must fall on the central axis of the Mauerlat or the lining board replacing it.

Subtleties of long-span hanging systems

Puff - the longest element of the hanging rafter structure. Over time, it, as is typical of all lumber, deforms and sags under the influence of its own weight. Owners of houses with spans of 3-5m are not too concerned about this circumstance, but owners of buildings with spans of 6 meters or more should think about installing additional parts that exclude geometric changes in tightening.

To prevent sagging in the installation scheme of the truss system for a large-span gable roof, there is a very significant component. This is a pendant called a grandmother. Most often, it is a bar attached with wooden surfs to the top of the truss truss. You should not confuse the headstock with the racks, because. its lower part should not come into contact with the puff at all. And the installation of racks as supports in hanging systems is not used.

The bottom line is that the headstock, as it were, hangs on a ridge knot, and a tightening is already attached to it with the help of bolts or nailed wooden plates. Threaded or collet type clamps are used to correct slack.

Adjustment of the tightening position can be arranged in the zone of the ridge knot, and the headstock can be rigidly connected to it with a notch. Instead of a bar in non-residential attics, reinforcement can be used to manufacture the described tightening element. It is also recommended to arrange a headstock or suspension where the puff is assembled from two bars to support the connection area.

In an improved hanging system of this type, the headstock is complemented by strut beams. The stress forces in the resulting rhombus are extinguished spontaneously due to the competent arrangement of the vector loads acting on the system. As a result, the truss system pleases with stability with a slight and not too expensive upgrade.

Hanging type for attics

In order to increase the usable space, the tightening of the rafter triangles for the attic is moved closer to the ridge. A perfectly reasonable move has additional advantages: it allows you to use puffs as the basis for filing the ceiling. It is attached to the rafters by cutting with a semi-frying pan with a duplication of a bolt. It is protected from sagging by installing a short headstock.

A noticeable drawback of the attic hanging structure is the need for accurate calculations. It is too difficult to calculate it on your own, it is better to use a ready-made project.

Which design is more cost effective?

Cost is an important argument for an independent builder. Naturally, the price of construction for both types of truss systems cannot be the same, because:

• In the construction of a layered structure for the manufacture of rafter legs, a board or beam of small section is used. Because layered rafters have two reliable supports under them, the requirements for their power are lower than in the hanging version.
• In the construction of a hanging structure, the rafters are made of thick timber. For the manufacture of puffs, a material similar in cross section is required. Even taking into account the rejection of the Mauerlat, the consumption will be significantly higher.

Saving on the grade of material will not work. For the bearing elements of both systems: rafters, purlins, beds, Mauerlat, attendants, racks, lumber of the 2nd grade is needed. For crossbars and puffs working in tension, you will need the 1st grade. In the manufacture of less responsible wooden slips, the 3rd grade can be used. Without counting, we can say that in the construction of hanging systems, expensive material is used to a greater extent.

Hanging trusses are assembled in an open area next to the object, then transported assembled upstairs. To lift weighty triangular arches from a bar, you will need equipment, for which you will have to pay rent. And the project for complex nodes of the hanging version is also worth something.

There are actually many more methods for constructing truss systems for roofs with two slopes. We have described only the basic varieties that are actually applicable for small country houses and buildings without architectural designs. However, the information provided is sufficient to cope with the construction of a simple truss structure.

Do-it-yourself gable roof truss system: device, design, installation

In order for the truss system of a gable roof to be built competently and firmly with your own hands, you need information about the rules and principles of the device, fastening and

Construction of houses

When building one-story houses, a roof with two slopes is very popular. This is due to the speed of construction of the structure. In this parameter, only a single-pitched roof can compete with a gable roof. In the device, a gable rafter roof is not too complicated. And you will successfully master this work on your own.

The design of the gable roof truss system

A gable roof consists of two inclined surfaces that have rectangular shape. Thanks to this, precipitation, which is represented by rain and melt water, flows off the roof in a natural way. The gable roof has a rather complex structure. It consists of such structural units: Mauerlat, rafter system, filly, ridge, roof overhang, bed, struts, puffs, crate and racks:

1. Mauerlat. This element performs the functions of transferring and distributing the load created by the rafter system on the load-bearing walls of the house. For the manufacture of Mauerlat, a beam is used, which has a square section - from 100 by 100 to 150 by 150 mm. It is better to use softwood. The beam is placed around the perimeter of the building and fixed to the outer walls. For fastening use special rods or anchors.
2. Rafter leg. Rafters form the main frame of any roof. In the case of a gable roof, they form a triangle. The rafters are responsible for the uniform transfer of loads to the Mauerlat. First of all, those that arise from precipitation, wind and the weight of the roof itself. For the manufacture of rafters, boards are used that have a section of 100 by 150 or 50 by 150 mm. Choose a rafter pitch of about 60-120 cm, depending on the type of roofing material. When using a heavy coating, place the rafter legs more often.
3. Skate. This element connects two slopes at the top of the roof. The ridge is formed after connecting all the rafter legs.
4. Filly. They act as a continuation of the rafters and form the overhang of the gable roof. It is customary to install fillies if the rafter legs are very short and do not allow an overhang to form. To make this structural unit, take a board that has a smaller section than the rafter. The use of fillies facilitates the construction of the truss system, as it allows the use of short rafters.
5. Eaves. This part of the design of the gable roof truss system is responsible for draining water from the walls during rain and at the same time preventing them from getting wet and quickly destroyed. The overhang protrudes from the wall, as a rule, by 400 mm.
6. Sill. It is located on the inner wall and serves to evenly distribute the load from the roof racks. For the manufacture of bedding, a beam is used, which has a section of 150 by 150 or 100 by 100 mm.
7. Racks. These vertical elements are responsible for transferring the load from the ridge to the interior walls. To create this element, prepare a beam that has a square section of 150 by 150 or 100 by 100 mm.
8. Struts. They are needed to transfer loads from the rafters to the load-bearing walls. Struts and puffs form solid construction which is called a farm. Such a device is designed to withstand loads at large spans.
9. Puff. This structural unit, together with the rafters, forms a triangle. It does not allow the rafters to part in different directions.
10. Crate. This design consists of boards and bars. They are attached perpendicular to the rafters. Sheathing is necessary to evenly distribute the weight of the roof covering and the loads created by weather phenomena on the rafters. In addition, the crate is required to fasten the rafters together. When arranging a soft roof to create a crate, you should not use boards and bars, but moisture-resistant plywood.

Varieties of gable roof truss system

There are gable truss systems with hanging and layered rafters. Ideally, the design contains a combination of them. It is customary to install hanging-type rafters if the outer walls are located at a distance of less than 10 m. Also, there should no longer be walls between them that divide the space of a residential building. The design with hanging rafters creates a bursting force transmitted to the walls. It can be reduced if you arrange a puff made of wood or metal and place it at the base of the rafters.

The rafters and tightening form a rigid geometric figure- triangle. It is not able to deform under loads that are in any direction. The puff will be stronger and more powerful if it is placed higher. The floor beams act as puffs. Thanks to their use, the hanging rafter system of a gable roof acts as the basis for the arrangement of the attic floor.

Laminated rafters in their design have a support beam, which is located in the middle. It is responsible for transferring the weight of the entire roof to the intermediate column or middle wall located between the outer walls. It is recommended to install rafters if the outer walls are placed more than 10 m apart. If there are columns instead of internal walls, you can alternate between rafters and hanging rafters.

Do-it-yourself gable truss system

The roof must be strong to withstand various loads - precipitation, gusts of wind, the weight of a person and the roofing itself, but at the same time light, so as not to put a lot of pressure on the walls of the house. A properly arranged gable rafter roof evenly distributes the load on all load-bearing walls.

Calculation of a gable roof

The choice of a gable roof slope will depend on the material you have chosen for laying on the roof and architectural requirements:

• When building a gable roof, remember that it must slope at an angle of more than 5 degrees. It happens that the slope of the roof reaches 90 °.
• For areas with heavy rainfall, and when the roofing does not fit snugly, steep slopes are made. In this situation, the angle should be 35-40 ° so that precipitation does not linger on the roof. But such an angle does not allow building a living space in the attic. The way out will be broken structure roofs. It will have a flat upper part, and on the lower part there will be a sharp slope.
• In regions with strong gusts of wind, sloping roofs are equipped. If constant winds prevail in the area, then make a slope of 15-20 ° for high-quality protection of the roofing.
• It is best to choose the middle option. Equip a gable roof that is not too steep. But also the slope should not be very gentle.
• When choosing a large angle of the roof, its windage increases, and, accordingly, the price of the gable roof truss system and the crate. After all, such a slope entails an increase in the area of ​​\u200b\u200bthe roof and, accordingly, the number required material- construction and roofing.

When buying materials for the construction of a gable roof, it is useful to calculate its area:

1. Find the area of ​​one slope of the structure, and then double the result.
2. Ideally, a slope is an inclined rectangle that is placed along a long load-bearing wall. To determine the area of ​​​​a slope, multiply its length by its width.
3. The length of the slope is equal to the length of the wall. In addition, the length of the ledge of the roof above the gable is added to the length. Remember that the protrusions are present on both sides.
4. The width of the slope is the length of the rafter leg. To it is added the length of the ledge of the roof above the load-bearing wall.

In order to properly design the structure, it is recommended to carry out an accurate calculation of the gable roof truss system, including determining the loads and characteristics of the rafters:

1. When erecting a roof for a standard building that has one floor, the design load on the roof will consist of two values. The first of them is the weight of the roof, the second is the load from external factors: precipitation and wind.
2. Calculate the weight of the roof by adding up the weight of each layer of the "pie" - heat-insulating, vapor barrier and waterproofing materials, truss system, battens and directly roofing material. Calculate the weight per 1 m2.
3. Increase the result by 10%. You can also take into account the correction factor. In our case, K=1.1.
4. If you plan to change the design of the roof over time and increase the angle of its inclination, then include a margin of safety in the calculation. Take more immediately high performance loads than those that you received at the time of calculation. It is recommended to build on the value, which is 50 kg per 1 m2.
5. When calculating the load exerted by atmospheric phenomena, take into account the climatic features of the area where the building is located. In this calculation, take into account the slope of the slope. If the gable roof forms an angle of 25 degrees, then take the snow load equal to 1.
6. If the roof is equipped with a greater slope - up to 60 degrees, the correction factor reaches 1.25. Snow load for an angle greater than 60 degrees is not taken into account.
7. The rafters transfer the entire load from the created structure to the load-bearing walls. Therefore, their parameters must also be taken appropriately. Select the section and length of the rafter leg, depending on the current load on the roof and the angle of the slope. Increase the values ​​obtained by 50% to ensure a high margin of safety.

Mauerlat installation methods

The construction of any roof begins with the installation of a Mauerlat:

• If logs or timber were used to build the walls, then the upper timber will act as a Mauerlat, as shown in the photo of the gable roof truss system.
• If you used bricks to build walls, then brick the metal rods into the masonry. They must have a cut thread for attaching the Mauerlat. Install rods every 1-1.5 m. Choose rods with a diameter of at least 10 mm. Lay waterproofing between masonry and Mauerlat.
• For walls made of ceramic or foam concrete blocks, pour concrete on top. Be sure to make the layer reinforced. It should have a height of approximately 200-300 mm. Be sure to attach metal rods that are threaded to the reinforcement.
• For Mauerlat, use a beam that has a section of 15 by 15 cm. It will act as a kind of foundation for the truss system.
• Lay the Mauerlat on the top edge of the wall. Depending on its design, the Mauerlat can be laid along the outer and inner edges. Do not place it close to the very edge, as otherwise it can be blown away by the wind.
• Mauerlat is recommended to be placed on top of the waterproofing layer. To connect all the parts into one whole, use bolts and metal plates.
• To avoid sagging, make a lattice of racks, struts and a crossbar. To do this, take boards measuring 25x150 mm. The angle between the strut and the leg of the rafter should be as straight as possible.
• If using a rafter leg that is too long, install another support. She must lean on the bed. Each element is associated with two adjacent ones. As a result, a stable structure is created around the entire perimeter of the roof.

Rafter leg attachment

Most the best way gable roof truss system - a combination of sloping and hanging type rafters. This design allows you to create a reliable gable roof and reduce the cost of Construction Materials. Consider the following recommendations when working:

1. Use only the highest quality wood as a material. Beams that have cracks and knots should not be used.
2. Rafters have standard dimensions - 50x150x6000 mm. When the beams are longer than 6 m, it is recommended to increase the width of the board so that the beams do not break under their own weight. Take boards 180 mm wide.
3. First, make a template for the rafter leg. Attach the board to the floor beam and the end of the ridge beam. Having outlined two lines, saw off a board along them. The template is ready.
4. Cut the rafters according to this pattern. After that, do the top washed down on them.
5. Take the resulting workpiece, bring it to the floor beam to mark the lower cut in place.
6. Install all rafters. At the same time, remember that after installing one leg, you must immediately install the opposite one. So you will quickly remove the lateral loads on the ridge beam.
7. If the slope is too long, then standard boards will not be enough to make a rafter leg. In this case, you can splice two boards together. To do this, sew on them a piece of wood of a similar section. It should have a length of 1.5 - 2 meters. According to the diagram of the gable roof truss system, the joint should always be at the bottom. Under it, install an additional rack.
8. Attach the rafter leg to the ridge beam with nails. Use self-tapping screws to fasten the rafters to the floor beam. Metal mounting plates are also suitable. In addition, a few nails are added.
9. If you are building a structure exclusively from hanging rafters, then skip the next step. When erecting a structure with layered rafters, you need to think about the supports that are installed on their floor. To reduce the deflection of the rafters, correctly calculate the location of such supports.
10. If you're building a gabled mansard roof, the intermediate studs will form the frame for the side walls.
11. When performing this work, maintain a certain step of the beams. Set its size at the design stage.
12. After installing the rafters, attach the ridge. It is located on their upper edge. For fastening use metal corners or staples. Bolts are the most popular.

Giving structure rigidity

After installing the gable roof truss system, strengthen it using the technology below:

• For smaller buildings, such as saunas, cottages, utility buildings, and roofs with a simple hanging rafter system, connect each pair of rafters from below with a tightening and from above using a crossbar.
• For large buildings that are light at the same time, provide a lightweight roof. The walls must support it.
• If the house has a width of 6-8 m, then the structure should be tightened. Install in the middle of the support. Such racks are called grandmas. Place them at each pair of rafter legs.
• If the span of the walls reaches 10 meters, then reinforcing beams will be needed. The struts act as an additional support for the rafter legs for tightening. They are attached to each rafter - closer to the ridge or in the middle of the rafter leg. Fasten them to the bottom end of the headstock and to each other as shown in the gable roof truss video.
• In a situation with long roofs, gable beams should be relieved. This is done by installing braces. The upper end should rest against the corner of the gable. The lower one is mounted on the central floor beam. For fasteners, use a beam that has a large cross section. So you can prevent them from breaking if there are strong gusts of wind.
• In areas where winds predominate, the rafters must be resistant to such influences. Strengthen them by installing diagonal ties. Boards are nailed from the bottom of one rafter to the middle of the next.
• For greater rigidity, when creating the most critical fasteners, it is better not to use nails. Use pads for this and metal ways fasteners. Nails will not be able to provide high-quality fastening, since the wood is capable of drying out after some time.

Lathing of the truss system

The final stage of the construction of the gable roof truss system is the creation of the crate. It is on it that you will lay the roofing. Carry out the work in the following sequence:

1. Select a dry timber for the crate. It should not have cracks or knots. Nail the bars on the bottom. Attach two boards near the ridge so that there are no gaps. The lathing must withstand the weight of the top roofing material and not sag under the weight of the workers.
2. If you will equip a soft roof, make two layers of sheathing. One is sparse, the other is solid. The same applies to roll roofing. To begin with, parallel to the ridge beam, place boards that are 25 mm thick and no more than 140 mm wide. A small gap is allowed - no more than 1 cm. Lay a continuous layer on top. To do this, it is better to use roofing plywood, slats or boards of small thickness. After that, check that there are no errors left on the crate - bumps and knots. Also check that the nail heads are not sticking out.
3. Lay one layer of timber under the metal tile. It should have a section of 50 by 60 mm. Proceed in the same way when using slate or roofing sheets become. Maintain a step between the timber, depending on the roofing you choose - from 10 to 50 cm. Hammer nails closer to the edges of the board, and not in the middle. Drive hats deep. So they will not be able to damage the roof later. If you are making a crate for a metal tile, then remember that the connection of the beam at the same level should fall on the rafters.

When you have installed and strengthened the gable roof truss system, you can start installing the roofing pie. Place between rafters thermal insulation material, a layer of vapor barrier and waterproofing. When using insulation in slabs, calculate in advance the pitch of the rafters for its installation. At the final stage, fasten the roofing material.

The device of the gable roof truss system, Building Portal

Construction of houses In the construction of one-story houses, a roof with two slopes is very popular. This is due to the speed of construction of the structure. For this setting,

The truss system is the roof frame, which is the basis for the roofing decking.

The rafter system is designed to withstand the load of the roof, taking into account natural loads: winds, snow, rain.

The roof option is approved at the design stage.

The purpose of the roof includes several functions: warmth in the house, protection of the premises from natural phenomena, therefore the truss system must be given special attention.

You can read how to calculate the truss system.

It is customary to classify truss systems so that the task of choosing a variant of the future roof is easier to solve:

• Shed. The most simple. More suitable for utility rooms, baths, small private houses, gazebos. Provides for the inclined position of the structure at a slight angle (no more than 25°);
• gable. Used for small houses and suburban buildings. They look like a triangle, in which the rafters are connected by a beam and are at a certain angle;
• Gable broken lines. They have two slopes with a fracture, thanks to which it is possible to increase the area of ​​the attic;
• Tri-slope (semi-hip). They have two trapezoidal slopes, which are connected by one end triangular slope (hip);
• Four-slope (hip). Used for residential buildings require a significant amount of labor. They have two end triangular slopes and two trapezoidal;
• Tent. Used for square buildings. They consist of four triangular slopes, the upper corner of which is connected in the center of the roof;
• Multi-forceps. Consist of trapezoidal or other slopes of various shapes, interconnected.

The most suitable designs for - and broken gable. There are others, but they are less common and not as practical as those listed above.

Rafter structures are also classified into:

• Hanging. With this type of roof frame due to the lack of load-bearing walls in the room;
• Layered. Option truss installation, providing support on a load-bearing internal wall or support in a building.

The calculation of the material for the roof frame when designing a building is based on the intended configuration and load. Do-it-yourself rafters are not difficult to do, it is important to approach the matter wisely.

Rafter systems of layered and hanging type

Calculation of the load on the rafters

To correctly calculate the load on the rafters, it is necessary to take into account many factors that can affect the severity of the structure.

Important metrics to consider:

• Constant load: includes a mass of roofing cake, covering material;
• Temporary load: constant and maximum amount of snow, rain, intensity of wind gusts, and in areas with high seismic activity - the action of storm winds, tornadoes, hurricanes.

In addition, you should keep in mind the mass and strength of the rafter legs, as well as pay attention to the fastening of the gable roof rafters and the installation option.

Scheme of truss systems

The distance between the rafters of a gable roof and the thickness of the rafters

The rafter pitch of a gable roof is the empty space between the rafters. The functionality of the roof depends on the correct calculation of the step. As a rule, the step is about a meter.

For a more accurate calculation of the distance between the rafters, there is a certain calculation scheme:

1. Determine the length of the slope.
2. The length of the slope is divided by the distance between the rafters.
3. To determine the number of rafter boards, one is added to the resulting value and rounded up. This determines how many boards are needed per slope.
4. The length of the slope is divided by the number of boards, get the distance between the rafters.

This calculation is not always final.

Additionally, you should take into account the load of the roofing (its mass), the thickness of the rafters, as well as the dimensions of the rafters for a gable roof.

The thickness of the rafter board largely depends on the covering material:

• . Boards are used with a section of 5x20 cm at a step of 60 to 90 cm with a decking of a batten with a section of 4x5 cm;
• . Rafter boards - 5x15 cm, step - from 60 cm to 95 cm;
• . The cross section of the board is 6x18 cm or 5x15 cm, the distance between the bars is from 80 cm to 130 cm;
• . The cross section of the rafter is 5x15 cm, 5x10 cm with a step of 60 cm to 90 cm;
• . The cross section of the beam is the same as on the corrugated board with a step of 60-80 cm.

All indicators should be taken into account and the thickness of the rafter should be accurately calculated so that there is no excessive load on the foundation.

Incorrect calculation of the length of the gable roof rafters, as well as incorrect calculation of the pitch indicators, can lead to sagging of the roof.

Do-it-yourself installation of gable roof rafters requires taking into account the weight of the rafter board and all additional structural fasteners.

What is the truss system

Rafter construction - a complex system and installing a gable roof truss system is not an easy task. truss system consists not only of rafter boards, but also of other additional elements:

• Mauerlat. An element that distributes the entire load evenly on the supports;
• Run. Boards fastening the legs of the rafter: at the top - a ridge, on the side - a side run;
• Puffs. Connecting beam, which prevents the divergence of the rafter legs;
• Struts, racks. Bars that fix the stability of the rafters, resting on the bed;
• . Lattice of bars, which is superimposed perpendicular to the rafters. Transfers the load of the covering material to the truss frame;
• . Connecting beam, which serves as a union of roof slopes;
• Filly. If the length of the rafter legs is insufficient, they are mounted to form an overhang;
• Roof overhang. Goes beyond the bottom line of the slope to prevent precipitation from falling on the walls.

The rafter system implies rafters, stretch marks, braces and racks located in the same plane. They are located in such a way that the main load of the roof structure falls vertically on the external load-bearing walls. Therefore, the manufacture of gable roof rafters is a very important process.

What is the gable roof truss system

Installation of a rafter system with layered rafters

A layered rafter system is used when the span does not exceed 6.5 meters.

In the presence of load-bearing structures inside the building, it is possible to install additional racks.

The main support of the rafter legs is the Mauerlat.

Mauerlat installation

Before mounting the Mauerlat, it is necessary to install an armored belt. It consists of a formwork in which reinforcement is laid and poured with concrete. At the base, with concrete that has not yet hardened, studs are installed, to which the Mauerlat is then attached.

Mauerlat - a beam that is laid on a support (bearing wall) and is the base of the truss frame. A layer of waterproofing material is preliminarily laid. If the length of the beam is not enough for the length of the wall, then it is increased.

• Check if the diagonals are equal. A discrepancy of a few centimeters can lead to a frame conversion;
• Fix the corners of the Mauerlat;
• Attach the Mauerlat with studs or wire. The studs are tightened in two stages, having previously drilled holes for them.

The stability of the roof structure depends on how firmly the Mauerlat is installed.

Therefore, it is necessary to take seriously the fastening of the Mauerlat to the bearing support.

Mauerlat installation

Sill

After the Mauerlat has dried (after 5 days), the installation of the bed is marked on the Mauerlat beam: its axis should be with the same indentation on each side of the Mauerlat beam. The bed is attached to a two-layer waterproofing layer with anchor bolts. To the wall with inside the bed should be fixed with twists of wire or staples. Next, markup is made for installing the rafters.

Installation of a gable roof truss system

The anchor points of the layered rafters are the walls and racks inside the frame. The rafters are mounted with hinged attachment points. When using sliders for fastening, a slight lowering of the roof frame is ensured in the first years of the roof's service life.

This installation method is necessary to prevent distortion, as in the early years the building settles a little.

Rafter beams should be fixed either by installing them in prepared grooves and strengthened with fasteners, or by attaching plank linings.

Installation of rafters

ridge knot

The rafters are joined end-to-end, cutting off the edge of the bar so that the angle when connecting opposite beams corresponds to the angle of the slope. Hammer the rafters under the ridge with nails. A variant is possible in which the beams are connected by bolts, a nail or a hairpin, that is, they overlap.

If necessary (if provided by the project), a cut is made in the rafter beams for attaching the ridge beam (purlin).

ridge knot

Racks

Racks are attached with a short span - in the center, on the sides and center - with a wider roof base. Fastening is carried out vertically from the ridge to the inner wall.

Run

Run - a connecting beam for fixing rafter legs. Fastens with bolts or brackets to the rack.

Filly installation

The final step in the installation of the layered system is the installation of filly with a short length of rafter legs for overhang. To install the visor, it is necessary to install additional small rafter boards.

Installation of a rafter system with layered rafters

Do-it-yourself gable roof truss system: installation with hanging rafters

truss system, equipped with hanging rafters, is a triangular structure, where the sides are rafters, and the base is a puff connected to the lower heels of the rafters.

Installation of a hanging-type truss frame can do without installing a Mauerlat: a board that is fixed on a two-layer waterproofing can replace it.

If the structure has a large span, then struts, headstocks, crossbars are attached to it.

Racks in the hanging system are not provided.

Puffs

The puff is the longest beam of the roof frame. To prevent it from sagging, it is necessary to fasten headstock - boards that are attached to the top of the structure on one side, and to the puff - on the other. Fasten with bolts or overlays made of wood. The slack can be adjusted using the threaded collars.

The device of the truss system

Installation of strut beams

The headstock can be supplemented with strut beams, forming a rhombus, where two struts are the lower sides, and the rafters are the upper ones, the upper corner is the ridge. Thus, the struts rest against the headstock, distributing the load.

Strut beams

rafters

Rafters of a hanging structure are mounted like a layered one. When installing attics, the puff is installed closer to the ridge, providing more space under the ceiling. The tightening in this case is fastened by cutting with bolts.

ATTENTION!

When installing a hanging system, a prerequisite for installation is the accuracy of calculations and the strength of the rafters and puffs.

The presence of errors leads to the displacement of the axes of the elements of the system, which provides a distortion of the structure.

How to install rafters for a gable roof will tell you this photo:

Rafter installation

hanging rafters

How to strengthen the rafters of a gable roof

It is necessary to reinforce the rafters of a gable roof when the load calculation is incorrect or frame defects are found.

Strengthening can be done with:

• Balok, which are installed in order to transfer the load to them;
• Strut mounting with an inclined mount with an emphasis on lying down;
• Overlays of double-sided rails;
• Increase in the section of the rafter beam in the place of supports on the strut by applying planking from boards with nails or bolts;
• board wall, which are attached to the rafters in places where snow is expected to accumulate to increase the bearing capacity of the rafters.

You can resort to strengthening the Mauerlat beam and the base of the rafter beam. Due to high humidity and reduced ventilation, these parts of the frame are more susceptible to decay, therefore, when arranging the roof special attention needs to be paid

Roof installation is a fairly complex construction process. For self assembly and installation of the truss system, you need to know how to properly connect the elements, what should be the length of the rafters, at what angle they should be tilted and, most importantly, what materials the roof is assembled from. Without special knowledge and skills, making a complex roof will be problematic. In this case, you can choose best option- do-it-yourself gable roof.

Design features of a gable roof

The gable roof is based on a triangle, which gives it rigidity. It contains the following elements:

• Mauerlat- these are bars laid directly on the outer walls around the entire perimeter of the house. The fastening of these elements is most often carried out by means of anchor bolts. The recommended material for the manufacture of elements is softwood. The cross section of the bars has the shape of a square with sides of 100 * 100 mm or 150 * 150 mm. It is on the Mauerlat that the rafters lie, and the load from the entire system is transferred to the outer walls.
• Sill- this is a beam of a certain length, against which the racks abut. It is laid in the direction of the internal load-bearing wall. The element is used in the arrangement of the roof on large houses.
• Struts- these are elements made of small bars. They are installed at an angle between the rack and the rafters. This arrangement helps to strengthen the rafters and increase the bearing capacity of the roof.
• Racks- these are roof elements located vertically. Through this element, the load from the ridge beam is transferred to the walls. Racks are located between the rafters.
• Puffs are beams that connect the rafter legs at the bottom. This element is the base of the truss triangle. Like struts, these beams make wooden roof trusses stronger and more resistant to various loads.
• rafter legs they are boards of a certain length, having a section of 5 * 15 cm or 10 * 15 cm. The elements are connected to each other at an angle, forming the top of a triangle. Two connected rafter legs are called a truss. The number of such structures is determined by the length of the house. In this case, the distance between farms can be no more than 1.2 meters and not less than 0.6 meters. When calculating the step of the rafter legs, the total weight of the roof, wind and snow load should be taken into account.
• Skate is located at the highest point of the roof and is a bar that serves as a connection for the slopes. This element is supported from below by vertical racks, and the ends of the rafters are attached to it from the sides. In some cases, instead of timber, two boards are used, connected at a certain angle and nailed to the top of the rafters on both sides.

A do-it-yourself gable roof involves making a crate from boards or timber, which are hammered onto the rafters in a perpendicular direction. Depending on the material for the roof, the crate can be solid or with gaps.

What is the difference between layered and hanging truss systems

Before you assemble a gable roof, you need to know some of the features of its structure. A hanging truss system is arranged when the house is small and there is no internal load-bearing wall. In this case, the rafters are connected at a certain angle, making appropriate saw cuts at their ends, nails are used for connection.

When constructing such a rafter system, the racks and the ridge are not made, and the emphasis of the lower ends of the rafters falls on the external load-bearing walls. To make the structure more durable, the upper puff should be located no further than 0.5 meters from the top. Sometimes floor beams are used as puffs. The absence of racks frees up attic space, which allows it to be used for arranging the attic floor.

If the house has an internal load-bearing wall, then it is more efficient to use a layered truss system. In this case, the bed is laid, the support posts are fixed on it, onto which the skate is nailed. This method is considered to be simpler and more profitable from the material side. When designing ceilings at different levels, the racks can be replaced with a brick wall, which will divide the attic space into two parts. A gable roof can also be made with different slopes along the length, which is also very beautiful and practical.

Do-it-yourself gable roof installation process

To answer the question of how to properly make a gable roof with your own hands, you need to follow the sequence of actions.

Installation of this type of roof involves work according to the following plan:

• Preparatory stage.
• Mauerlat fixing.
• Farm assembly.
• Installation of trusses on floors.
• Skate device.
• Stuffing the crate.

Preparatory stage

Before starting work, prepare a set necessary tools and materials:

• Hammer and hacksaw.
• Square and level.
• Fasteners.
• Boards, beams and roofing material.

All wooden materials should be treated with antiseptic solutions and flame retardants and dried well.

Mauerlat installation

In houses made of wooden logs or timber, the top row of the log house plays the role of the Mauerlat, which makes the process easier. On the inside of the log, a groove is cut into which the rafter leg is installed.

In brick or block houses, the Mauerlat is laid as follows:

• When laying the last rows, threaded metal studs are mounted in the masonry. They should be located around the entire perimeter of the house at a distance of about 1.5 meters from each other.
• The upper part of the walls is covered with roofing material in several layers, piercing it with studs.
• Holes are drilled in the beams in accordance with the location of the studs.
• Beams are laid, putting them on studs. At this stage, it is important to ensure that the beams are laid exactly horizontally, and the opposite elements are parallel to each other.
• Nuts are tightened on the studs, pressing the Mauerlat. See also: "".

The result of this stage should be a rectangle of the correct shape, located on the same horizontal line. This design makes the structure more stable and facilitates subsequent work. The completion of the work is cutting grooves in accordance with the size of the rafters.

Hanging truss system

The length of the rafters is determined by the distance between the external load-bearing walls and the angle of connection of the rafter legs. The optimal length is 4-6 meters, given the eaves overhang of 50-60 cm. These parameters should be taken into account when solving the problem of how to make a large roof.

At the top, the rafters are fastened in different ways: end-to-end, overlapped or "in the paw" with cut grooves. The rafters are fixed with bolts or with the help of metal plates. A puff is mounted a little lower and finished structure farms are lifted to the installation site.

First, trusses are installed along the edges, checking their verticality with a plumb line. At the same time, the overhang is adjusted. The rafters are attached to the Mauerlat with bolts or steel plates. Sometimes temporary braces are used to support the truss during installation. Inserting the remaining rafters, maintain the same distance between them. After installing and fixing all the trusses on both sides of the upper slope, I nail boards with a section of 5 * 15 cm.

Methods for fixing hanging rafters on the Mauerlat

Hanging rafters can be attached to the Mauerlat in several ways:

• A groove is cut out on the rafters, and a metal pin is driven into the wall at a distance of 15 cm from the upper edge. The rafter is placed on the Mauerlat, tied with wire and pulled to the wall. The wire is wrapped around the pin.
• The second method involves laying out a brick stepped cornice. At the same time, Mauerlat is laid along the inner edge of the wall and a groove is made in it for the rafter leg.
• When using the third option, the rafters rest against the floor beams, which have an outlet for the perimeter of the house up to half a meter. Beams are cut at an angle and fastened with bolts. Using this method, a do-it-yourself roof is assembled without a Mauerlat.

How to install layered rafters

Rafter rafters are installed in the following order:

• The load-bearing wall, located in the center of the house, is covered with waterproofing material.
• A bed is laid on top and fastened with bolts or metal brackets.
• Racks of bars with a section of 10 * 10 cm are put on the bed.
• Runs are nailed on top of the racks in the horizontal direction, strengthening the structure with temporary struts.
• Perform the installation of rafters and their fixation.

After installing the main structural elements, wooden surfaces are treated with fire retardants.

How to make a crate

Before laying the battens, the rafters are covered with a layer of waterproofing, protecting it from getting wet. Waterproofing is laid in a horizontal direction, starting from the eaves and rising up. The strips are laid with an overlap of 10-15 cm, the joints are sealed with adhesive tape.

A ventilation gap is required between the crate and waterproofing; for this, slats no more than 4 cm thick must be filled on each rafter leg.

Now you can sheathe the truss system. The crate can be made from a 5 * 5 cm timber or boards having a thickness of not more than 4 cm and a width of more than 10 cm. Start filling the crate from the bottom of the rafters, maintaining a certain step.

After installation, the battens begin to sheathe the gables and overhangs. Depending on the construction budget and the desire of the homeowner, you can make a do-it-yourself gable roof with gables made of plastic, corrugated board or wooden planks. Knowing how to sheathe the gable of the house with a profiled sheet, you can do the installation yourself. Sheathing is attached to the sides of the rafter leg, using nails or self-tapping screws. Overhangs can be sewn with all sorts of materials.

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

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

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

General arrangement of a gable roof

Basic concepts

Structural elements of the gable roof truss system

Let's make a reservation right away that this scheme, of course, cannot reflect the entire possible variety of designs, but the main parts and assemblies on it are shown quite clearly.

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

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

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

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

To form a cornice overhang, the rafters are extended with “fillies”

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

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

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

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

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

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

Some differences between hanging and sloping gable roof systems

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

Laminated rafter system

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

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

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

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

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

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

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

Hanging rafter system

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

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

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

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

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

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

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

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

Calculation of the basic parameters of the gable roof truss system

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

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

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

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

chainsaw prices

chainsaw

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

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

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

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

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

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

H =f × tga

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