Roofs for the house scheme. Do-it-yourself gable roof truss system: an overview of hanging and layered structures. We list a few important facts about their design.

One of last stages private housing construction is a device for the roof of a private house correct scheme which is of particular importance. The roof performs many different functions, but one of its main purposes is to protect the interior of the building from natural phenomena: wind, sun, precipitation. Not one building, especially residential buildings, can do without roof structures, during the construction of which it is important not to make even the most elementary mistakes inherent in inexperienced builders. Otherwise, after a few years of operation of the house, the roof will already have to be repaired.

And the repair of the roof structure is a rather laborious work, accompanied by a number of difficulties, infringement of the comfort of living for a given period, and, of course, additional financial costs. Therefore, before carrying out the installation of the roof of a private house, you need a diagram with a detailed reflection on it of all structural elements roofing, building materials used, other details.

In this article

Options for roofing schemes for private housing construction

During the construction of private houses, pitched roof structures are often used to cover them, which can be single-pitched or multi-pitched.

Drawing pitched roof used mainly for small simple outbuildings.

Varieties of multi-pitched roof structures

Double pitched roofs. The most common type of construction, under which you can use any roofing material. Such a roof is quite simple in terms of its installation, but at the same time reliable and durable.
Hipdesigns- roofs with an envelope according to the scheme four pitched roof when two slopes are made in the form of a trapezoid, the other two are in the form of a triangle. Most often used to cover houses in the southern regions, as they are distinguished by their excellent ability to withstand significant wind loads.
Half hip roofs. This is a subtype hip design, in which the length of the side slopes along the slope line is less than the main slopes. Most of such structures are in regions with adverse climatic conditions.
hipped roofs. Their design consists of four triangular-shaped slopes, the tops of which are connected at one point.
Broken roof structures. Such roofs belong to gable roofs, consist of four surfaces that intersect each other at an obtuse angle.
Multi-gable roofs. Such roofs have enough complex scheme construction, which is most often used to cover houses elite class with a complex geometric configuration.

Pitched roofs, depending on their design features, are divided into attic, non-attic roofs. In the first case, an attic space is arranged between the ceiling and the roof (a separate type of pitched roof). In the second case, all load-bearing components of the roof structure are also the floor of the outer floor of the building (combined type of pitched roof).

To cover private houses, an executive scheme of attic type roofing is often used.

Structural features of the attic roof

When constructing roofs with an attic space, the following details should be considered:

Particular attention must be paid to the parameters of the floor spans. If the width is large enough, then the rafter leg should have a maximum cross section. For example, a floor span pitched roof is 5 meters, then the cross section of the beam used for the manufacture of rafters should be 15x5 cm, and the installation step is about one meter.

If you make a partial section of the roof with an attic, you can consider its main components:

roofing material;
ridge beam;
load-bearing inner wall;
rafter legs;
support racks;
Mauerlat;
struts;
crate;
metal fasteners.

Be sure to take into account the slope of the slope. A roof with slopes at a large angle will be released from precipitation faster, since water and snow on such a surface are not able to hold. Therefore, for roofs with a slope of 50º, rafters with a smaller cross section can be used than for roofs with a slope of less than 20º. These data must be reflected in the scheme of arrangement of the roof structure.

It is also worth remembering the period of operation of individual parts of the roof structure, depending on the building material used for their manufacture. For example, load-bearing elements made of natural wood, can serve without loss of initial strength for about 30 years, reinforced concrete structures - 50 years. At proper organization wooden rafter system, proper care during operation, it can not be changed for 100 years. When choosing the design of the future roof, it is necessary to take into account the expected conditions for its operation.

Particular attention in the arrangement of the roof is paid to the fire resistance of the material used, which is additionally processed with specialized non-combustible compounds.

When designing a roof scheme, its thermal properties must be taken into account without fail.

When calculating the cross-section of a beam for a rafter system, it is also necessary to take into account the mass of the roofing "pie".

The main nuances that must be considered when making a do-it-yourself rafter system

In order to prevent the deflection of the building legs in the event of the manufacture of rafters of insufficient section when calculating the required roofing material, the farm is necessarily equipped with additional support posts, struts, puffs.
When calculating the roof, it is imperative to take into account the possibility of disruption by strong gusts of wind of the roofing material. To prevent this, rafter legs must be fixed with brackets and additionally with steel wire (section up to 8 mm, but not less than 4 mm).
For the manufacture of a roof ridge run, it is recommended to use logs (boards in the last resort, the thickness of which should be 5 cm or more).
If the roof scheme for attic construction, then the puffs are not equipped, they will be compensated by overlapping the floors, which will subsequently serve as the floor of the attic.
From used roofing the density of the crate will depend, the main building material for which are logs (boards) and tes. The main purpose of the crate is to take on the load from the entire roof covering, then transfer it to the rafter system.
Depending on the type of roof being built, the crate is sparse, solid. A feature of the sheathing of a continuous type is as follows: it is made of two layers, a gap of no more than 2 mm is allowed between the boards. In this case, the first layer is sparse, the second one is mounted at an angle of 45º relative to the first one. This is due to the peculiarity of laying some types of materials for the roof. When arranging a sparse type crate, a distance of 6 to 14 cm can be maintained between the boards (depending on the snow cover of the region in which the house is being built).
You also need to remember that a continuous crate is always performed on the slopes of the roof, the joints of the rafter system.

The main features of the roof design are necessarily reflected in the drawing up of the scheme.

When planning to cover the roof of a house with your own hands, it must be borne in mind that when choosing a scheme for its arrangement, it is worth relying not only on the conditions for its further operation, but also on your own financial capabilities. It is also important to understand that the safety of the residents of the house will depend on the quality of the installation of the roof of the house with their own hands. Before using a specific roofing structure scheme, you can first study their features from photographs on the Internet.

Roof construction is the most important part of building a house. It is she who will be responsible for protecting housing from precipitation. Therefore, it is necessary to design the shape of the roof as correctly as possible.

The roof consists of wooden or metal beams that form the supporting structure of the roof. Rafters and trusses are special elements that are made at an angle and, in turn, are load-bearing. The roofing is carried out using a waterproof coating and wooden crates. For maximum home safety, the load-bearing part of the roof must be as strong and stable as possible, and the covering must be made of lightweight materials with a waterproof property, such as isoplast. Roofs can be with or without an attic. Attic roofs protect the premises exclusively from atmospheric precipitation, and a special attic floor is responsible for the thermal insulation of the house.

The main types of roof shape

There are several types of roof shapes: single-pitched, gable, hip, semi-hip.

Undoubtedly the most simple form roofs are shed. Such a roof is most often used for the construction of utility rooms or outbuildings.

For residential buildings with a rectangular shape, in most cases, two pitched roof. This shape of the roof consists of two planes that are at an angle to each other. At the same time, these planes are fastened with a special ridge.

Houses that are square in shape hip roofs(tent). It is this form that has four inclined planes. truss system hipped roofs have relatively short beams. The intersections of inclined planes are called ribs, triangular sections are called hips.

To use the attic space for household needs or housing, use attic types roofs with the possibility of installing skylights. The angle of the roof slope can vary from 13 to 50 degrees. Often the angle depends on the weather conditions typical for the area of the building. In places with high rainfall, the slope is made steep.

rafters

Rafters are the load-bearing elements of the roof. They have the task of supporting the crate and relieving it of the load arising from the weight of the roof, snow or wind. There are 2 types of rafters: layered and hanging.

Rafter rafters are used in houses with supporting walls. This type of rafter is the simplest, despite the need for internal walls or partitions. They consist of two rafter legs not connected to each other. One part of the leg rests on the supporting wall, and the second part on the run, which is supported by the rack. The racks are supported by internal walls. If the rafters are more than 4 meters, then under them it is necessary to install struts that will remove the excessive load on the rafters. To install layered rafters, at least 2 fixed places of support for the ends of the rafter legs on the longitudinal wall and in the ridge are required. Thus, the expansion of the wall is excluded.

Hanging rafters are used when there are no intermediate supports in the building, and the length of the roof span is at least 7 meters and not more than 12 meters. Or in the case when the walls of the house are made of raw materials. Rafters consist of rafter legs and puffs. Between themselves they are connected by notches or nails. The lower part of the legs rests against the walls of the building, and the upper part is connected to the opposite rafter leg in the ridge. The puff, in turn, perceives the thrust that occurs between the rafter legs.

To prevent deflection of the rafter legs, it is recommended to install a crossbar. In the ridge, the rafters are connected with nails or a simple slotted spike. At the junction of the rafters with struts, cuts and staples are used. When connecting the rack and the run, only a spike is used, and the spike is installed on the end side of the rack, and a special nest is cut out in the run.

The connection between the puff and the rafter leg is performed in a tooth or with the help of bolts. To prevent chipping of the ends of the puffs, the notch is at a distance of 250-300mm, the tooth must be set at a distance? tightening thickness. A double tooth is used in case of an increase in the area of \u200b\u200bsupport. The height of the 1st and 2nd tooth is taken as? tightening thickness. An emphasis and a spike are used in the place of tightening the first tooth, and one stop is enough for the 2nd tooth.

To prevent water from entering the walls, overhangs of rafters 550 mm long from the outer border of the wall are used. If the length of the rafters is not enough to close the outer edge of the wall, then they are lengthened by nailing pieces of boards placed on the edge to the end of the rafters.

Be sure to connect the rafters to the walls. If the building is stone or brick, then clamps are made from a thin wire with a diameter of 4–6 mm, with the help of which the ends of the rafters are tied and connected to a pin driven into the wall. In the case of a wooden building, the rafters are connected with brackets.

For the manufacture of rafters, you must perform a special template. The production itself takes place on the ground, on a flat area. For the manufacture of a template, a tesin is used, the length of which is equal to the length of the puff, and another gorse is nailed in the center perpendicular to it. After choosing the angle of the roof, it is necessary to determine the height of the ridge. To do this, measure the top of the ridge on the second cleft and attach 2 rafter legs. Then for all important nodes template mark the places of the cuts and prepare the remaining parts roof frame.

Mauerlat

Mauerlat - a special design on which the lower ends of the support beams are located. It is a bar or log with a diameter of 18-22 cm. Between the Mauerlat and the brick (stone) wall it is necessary to put insulating materials, such as roofing felt. The material is necessary to evenly distribute the weight of the roof on the walls of the building. Distances between rafters are usually in the range of 1.2m to 2m.

Roof frame assembly

Using the template, all are cut and assembled necessary elements roofs. Then a test assembly of the frame is carried out on the ground at flat surface. The rafters must be placed on the Mauerlat to check all calculations. If the calculations are correct, then notches are made at the tightening points on the Mauerlat and at the ends of the rafters. The puff is installed on the Mauerlat and rafter legs are placed on it. If the notches converge, then proceed to the next step, if not, then the notches must be adjusted to the correct value. After fitting the notches in the lower part of the rafters, it is necessary to adjust the notches in the place of the ridge.

After the final checks, they begin to assemble the roof frame on the house itself. First, the Mauerlat is laid, puffs are cut into it. On the puffs put scaffolding from the boards. Further, rafters are raised to the roof, which are connected to puffs and a ridge. To keep the structure in a stable position, struts from boards or bars are used. The assembly begins with the erection of 2 extreme rafters, then a cord is pulled between them and the subsequent rafters are aligned with respect to it.

The last stage of building a house is the arrangement of the roof. Traditionally, a gable roof is erected for any residential building, for outbuildings - a shed roof. The technological processes of installation, fastening and arrangement of a roof with a truss structure in a gable version of the roof have been perfected for centuries, and these operations do not change depending on the type of roofing materials (clay tiles, corrugated board, metal tiles, asbestos slate, metal or plastic).

Varieties of gable roof

People say: “the roof of a house”, that is, it means not only the shape, but also the reliability of the design, which has a long list of advantages:

A variety of options for the roof scheme and architectural forms of the roof;
Simple calculations and profitability of the roof;
Natural runoff of atmospheric precipitation;
The simple geometric shapes of the roof provide a low chance of water accumulation and roof leakage;
Large usable attic area, it is possible to make an attic;
Good maintainability, high strength, durability and wear resistance of the roof of two slopes.

The three most common gable roof options are:

Symmetrical gable roof: This is the most popular solution due to its absolute reliability and ease of execution. Symmetrical slopes evenly distribute all the loads on the Mauerlat and the walls of the house. The choice of roofing material does not depend on the type and thickness of the thermal insulation layer. Bearing loads can be easily increased by making the truss system from a thicker beam, jibs and struts can be attached anywhere. A negative factor - a full-fledged attic in such an attic will not work - or there will be low sloping walls with many "dead" zones, or a small but rectangular room;
Asymmetric roof of two slopes: Different slope angles of the slopes reduce the useful area of the attic, but on one side you can make a full-fledged living space. Due to different angles of the roof slope, the load on the load-bearing walls and the foundation of the house is distributed unevenly, which requires recalculation of the load capacity of the base and bearing walls at home, recalculating the types of materials and their quantity, as well as changing the methods of insulation, waterproofing and finishing;
Asymmetric gable roof with internal or external break: Allows you to design living spaces without regard to the roof structure. Disadvantages - the same as in the paragraph above.

Preparation for the construction of the roof of the house

The shape of the roof and its design can be chosen based on - the dimensions of the building, the material of the bearing walls, the geographical location of the site play a role. These and other parameters specified in the project determine what loads the gable roof can withstand during operation.

The angle of inclination of the slopes has a certain optimal range in which weather conditions have the least effect on the formation of maximum roof loads. If the slope angle of the slope is ≤ 400, then this limits the possibilities of equipping the attic or a full-fledged room in the attic, and the slope angle ≤ 100 increases the load on the roof from rain, wind or snow. If you want to definitely have an attic or a room in the attic space, it is better to use the option of a broken asymmetric roof, and if the walls of the house are more than 6 meters long, then the rafter system must be strengthened with additional runs.

When calculating building materials for a gable roof, it is necessary to proceed from the axiom that the weight of roofing materials should be as small as possible so as not to load the walls and the foundation of the house. wooden elements will be stronger not only with an increase in their cross section, but also with the use of suitable wood species. The main parameter in the calculation of materials is the total roof area, and a symmetrical design in this regard is calculated more easily than others - it is enough to know the perimeter of one slope, double its area, and get an accurate result.

The main load from the weight of the roof is assumed by the long walls of the house, so the truss system is built on the principle of load distribution along the system. Not for home large sizes(≤ 6 m) it is more practical to use a hanging rafter system (without supports), when building a larger house, a layered rafter system with a more complex configuration is used.

Finished gable roof for a private house consists of the following elements and nodes:

Mauerlat is a wooden (sometimes metal, if the roof is covered with rolled metal) beam or log, which is attached to the surface of the outer walls to support the rafters on it;
The rafter system, the design of which is selected based on the design of the house;
Struts (diagonal fastening of the rafters between themselves) and skates (beam along the ridge of the roof for fastening the slopes);
Lathing - serves for the installation of the roof and elements of hydro-sound insulation;
Warming and moisture protection;
Roof covering.

How to mount a mauerlat

Mauerlat on the walls of the house holds the weight of the roof, evenly distributing it on the walls and the base of the house. The width of the Mauerlat beam should be equal to the width of the wall. The beam is impregnated with an antiseptic and substances that increase the fire resistance of wood. The outer border of the Mauerlat should not protrude beyond the outer edges of the walls.

The Mauerlat is attached in different ways. A steel wire Ø 8-12 mm is laid in the brick wall, holes for the wire are drilled in the tree, and through them the timber is tied to the wall. Also, the beam can be fixed with staples, threaded studs in one or two teeth, metal plates, wooden surfboards or anchors through the same holes in the Mauerlat. The pediments and the lower edges of the batten are attached either directly to the Mauerlat, or to a beam of a smaller section, which is nailed (screwed) to the upper trim.

floor beams

When arranging beam ceilings for the roof of a private house, it is necessary to use wooden beam section 200 x 100 mm. The larger the area of \u200b\u200bthe house, the larger the cross section of the supporting beam should be. The installation of beams begins with the fastening of the extreme elements along long wall Houses. Then the points are marked at which the remaining floor beams will be attached.

The crate is mounted on longitudinal beams, which are located at a distance of 50-60 cm, and are attached to the Mauerlat with nails 200 mm long or by any of the above methods. The beams are carried out beyond the edges of the walls to a distance that determines the width of the cornice - from 30 to 50 cm. The cornice will be nailed (screwed) from below to these beams. Since the pediment will be equipped at the ends of the roof, a tie-in is made into the groove on the Mauerlat transverse beam to fasten the cornice and the pediment. When erecting a sloping roof for the attic, the gable will have a fairly large area, so it is necessary to ensure the design of the ebb and gable overhang.

The rafters of a gable roof are several of the same wooden beams the same length and section. After the installation of the floor beams, a ridge beam is attached, for which beams with a section of 100 x 50 mm are fastened with spacers along the central longitudinal axis of the house. Rack height in standard scheme gable roof is equal to the distance from the floor to the upper surface of the Mauerlat. Instead of a beam for a ridge, boards with a thickness of 50 mm can be used.

Before installing the truss system, it is recommended to make a large-scale template. For this board from roof structure you need to attach one end to the beam, the other to the ridge, and mark its length. This will be the template length of the rafters.

The truss system is also mounted according to the template, observing the sequence of processes. After installing and fixing from the lower end of one rafter beam, you must immediately fasten the opposite rafter, and connect the beams with their upper ends to each other through the ridge. The rafters are nailed to the ridge beam, and to the floor beam - with steel brackets or a corner, self-tapping screws or anchors. For a roof of any shape with two symmetrical or asymmetrical slopes, boards are attached along and across the rafters to give the system rigidity.

Fronton and cornice

The pediment is sewn up after the construction of the truss structure is completed. Modern materials are increasingly replacing traditional wood when sheathing gables, and now they use clapboard, siding, corrugated board, and other durable decorative Decoration Materials. Any sheathing material is attached to the frame, which is mounted in advance. Regardless of whether or not there is a room or an attic in the attic, a window opening must be left in the pediment - for ventilation and minimal natural lighting of the space.

The cornice must be equipped around the entire perimeter of the house - it is necessary for moisture and wind protection of the truss structure, the walls of the house and the foundation. Since every self-respecting owner necessarily makes drainage around the perimeter of the house, they are also attached to the eaves, and drain pipes- to the walls. Plastic system drainage is mounted on plastic clamps. From below, the cornice boards or the frame of the cornice are painted, sheathed with siding, clapboard or corrugated board - in unison with the pediment finish.

The roof is mounted on the crate, and, based on the type of roofing materials, the sheathing is first made with vapor barrier, hydro- and heat-insulating materials. For the roof, you can use ondulin, metal tiles, ceramic materials, soft tiles, etc.

Self-tapping screws for roof construction must have a manufacturer's mark and EPDM gaskets ≥ 2 mm thick, otherwise roof leakage cannot be avoided;
Poor quality protective covering fittings under the influence of weather conditions will quickly collapse, which will lead to leakage at the attachment points, and ugly appearance in the form of rusty or dirty spots;
The absence of a snow retention system is the possibility of unexpected snow coming off the slopes, which can lead to failure of the roofing and drainage system;
Poor ventilation is the formation of condensation in the under-roof space.

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 building a gable roof truss system with their own hands, and for those who decide to resort to the services of a hired team of builders.

In the construction of a truss frame for pitched roofs, wooden and metal beams. The starting material for the first option is a board, log, timber.

The second is constructed from rolled metal: channel, profile pipe, I-beam, 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 for the use of 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 welding machine and welding 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 a truss 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 the brick walls is sometimes specially laid out so that something like a low parapet is obtained along the outer perimeter. 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 available home master there is no design development, 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 laying clay tiles, for example, the optimal distance between the rafters will be 0.6-0.7 m, and for a profiled sheet, 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 design features buildings, tritely dividing the length of the slope into equal distances. For insulated roofs, the step between the rafters is selected based on the width of the thermal insulation boards.

On our website you can find, which may also help you a lot during construction.

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 of the internal space of the operated attic.

If the attic is cold and the organization of useful premises is not supposed to be in it, then the layered construction 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 detecting vertical deviations of brick and concrete walls, remove them 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 everything wooden details structures before installation with flame retardants and antiseptics.
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.

Another useful video about the construction of a gable truss base with your own hands:

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 roof truss will have to be installed 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, strut beams complement the headstock. 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 benefits: it allows you to use puffs as a base for ceiling filing.

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 load-bearing elements both systems: rafters, girders, 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.

Video instruction on the installation of a truss structure of a hanging category:

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.

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The roof, being the final part of the construction of a building for any purpose, is necessary to create reliable protection from such atmospheric phenomena as rain, snow, wind, sun rays. Its main parts are the rafter system and the top coating, which consists of several layers. To build them, you need a roofing scheme.

Types of roofs for a private house

When is being erected a private house, usually build a pitched roof, which can be a single-pitched or multi-pitched structure. Shed is usually equipped on buildings for economic use.

A multi-pitched roof is often installed on buildings built in the form of the letter L, P or T.

Such a roof, depending on the number of slopes and their shape, happens:

lean-to;
gable;
broken line;
tent;
hip;
attic;
multi-forceps.

gable roofs . This type of roofing is the most common, as it fits almost every roofing material. They are easy to install and have a solid construction.

broken roofs . They are 4 surfaces intersecting at an obtuse angle.

hipped roofs . The original ones consist of four triangular-shaped slopes, the tops of which touch at one point (see photo).

Half hip roofs . They are considered a type of hip roofs. Along the slope line, their side slopes are shorter than the main ones. Typically, half-hip roofs are erected in areas where adverse climatic conditions are observed.

Multi-gable roofs . The plan of the roof of a house of such a structure that is not easy to install during its construction is simply necessary, since it has the most complex geometric shape (in more detail: "").

Also, all pitched roof types are divided into attic (separate) and non-attic (combined). In the first case, an attic space is equipped between the roof and the ceiling of the house. The second option implies that the carrier system is also a floor for the top floor of the building. The attic type is used more often than the non-attic type. Still such roofs are called mansard.

Structural features of the attic roof

When building roofs with an attic, a number of nuances must be taken into account. First of all, the dimensions of the overlapped spans are taken into account. If their width is large, then the rafter leg will have a maximum section. For example, with a 5-meter span, to cover a shed roof, rafters with a bar section of 150x50 millimeters and an installation step of about 1 meter will be required (more details: "").

If you look at the section of the roof with an attic space, you can see that the main elements of its design are as follows:

rafter legs;
Mauerlat;
ridge beam;
struts;
racks;
crate;
fixing hardware;
material for covering the roof surface;
interior load bearing wall.

Secondly, the angle of the slope of the slope is certainly taken into account. Roofs with steep slopes are quickly cleared of precipitation, since snow and water do not linger on their surface. Therefore, the section of the rafters with a roof slope of more than 50 degrees is selected with smaller dimensions than with a slope of about 20 degrees, this should be taken into account initially ..

Thirdly, one should not forget about the service life of the roof elements, depending on the material of manufacture. So load-bearing structures made of natural wood retain their strength for three decades, and those made of reinforced concrete and wood for 50 years. In the case of well-executed installation and with regular maintenance, a wooden truss system can last about 100 years. When choosing a structural solution for a roof, one should not forget about the conditions in which it will be used.

Fourthly, serious attention should also be paid to the fire resistance of elements. To reduce the likelihood of fire, they are covered with cement-sand plaster or special protective paint, non-combustible mats are laid.

Fifthly, when a house roof scheme is designed, its thermal characteristics must be taken into account.

Sixthly, when calculating the cross section of the rafters, the weight of the roofing "pie" is certainly taken into account when compiling.

House roof device, video instruction:

Roof frame materials

When drawing up a diagram of the roof of a house, you need to have graph paper, a tape measure, a ruler, a pencil and a calculator with you.

The creation of the bearing part of the roof involves the use of:

wooden and metal-wood systems;
reinforced concrete and steel trusses.

As the roof section shows, the truss system consists of:

wooden beams (rafter legs), which bear the load from the roofing;
timber (Mauerlat), which is a support for the installation of rafters;
screeds;
racks;
laths for battens, sometimes moisture-resistant plywood is used.

The type that the truss system has (layered or hanging) depends on the material for creating the roof surface. In houses built of stone or bricks, a Mauerlat is used when installing a layered system, and in log cabins- upper crowns. Rafter legs are installed at intervals of 0.6 to 2 meters. The step size is determined taking into account the degree of load, the cross-section of the beam and the type of wood, usually coniferous.

The support for the middle of the truss system is an internal wall or columnar support. Rafters are used if the distance between opposite walls does not exceed 6 meters. In the presence of an additional support, the permissible span increases to 12 meters.

Hanging rafters are used in the presence of external load-bearing walls and the absence of intermediate reference points. Since the load in this case on the rafter legs increases, wooden or metal puffs are used - they can be attached not only at the base of the rafters, but also slightly higher.

In the production of metal-wooden structures, metal and wood are used - trusses, arches and frames are created from them. The upper belt is made of wood, and the lower one is made of profiled rolled products, as well as reinforcement (more details: ""). They are the best option creating a frame with a span of up to 20 meters. Reinforced concrete rafters are commonly found on industrial buildings or on agricultural buildings.

Steel trusses, consisting of pipes with a square section, and paired corners are necessary to cover spans no more than 30 meters long. The choice of roof schemes depends on the conditions of their use and on the financial capabilities of the developer.