Device gable roof rafters roof plan. Roof truss system: elements, types, fastenings, calculation. Calculation of the section of the rafters

Rafters serve as the basis of the entire roof structure, and their installation is one of the most important tasks in building a house. The frame of the future roof can be made and installed independently, observing the technological features of roofs of different configurations. We will give the basic rules for the development, calculation and selection of the truss system, and also describe in stages the process of installing the "skeleton" of the roof.

Rafter system: rules for calculation and development

The truss system is a load-bearing structure capable of resisting gusts of wind, taking on all external loads and evenly distributing them to the internal supports of the house.

When calculating the rafter structure, the following factors are taken into account:

1. Roof pitch:
   • 2.5-10% - flat roof;
   • more than 10% - pitched roof.
2. Roof loads:
   • constants - the total weight of all elements " roofing cake»;
   • temporary - wind pressure, snow weight, weight of people who carry out repair work on the roof;
   • force majeure, for example, seismic.

The magnitude of snow loads is calculated based on the characteristics of the climate of the region according to the formula: S=Sg*m, Where Sg- snow weight per 1 m2, m- calculation coefficient (depends on the slope of the roof). The determination of the wind load is based on the following indicators: type of terrain, wind load standards of the region, building height.

Coefficients, necessary standards and calculation formulas are contained in engineering and construction reference books

When developing a truss system, it is necessary to calculate the parameters of all components of the structure.

Roof structure elements

The truss system includes many components that perform a specific function:

Materials for the manufacture of rafters

Rafters are most often made from coniferous trees (spruce, larch or pine). For the arrangement of the roof, well-dried wood with a moisture level of up to 25% is used.

The wooden structure has one significant drawback - over time, the rafters can be deformed, so metal elements are added to the supporting system.

On the one hand, the metal adds rigidity to the truss structure, but on the other hand, it reduces the service life. wooden parts. Condensation settles on metal platforms and supports, which leads to decay and damage to the wood.

Advice. When installing a truss system made of metal and wood, care must be taken that the materials do not come into contact with each other. You can use moisture barriers or apply film insulation

In industrial construction, metal rafters made of rolled steel (I-beam, brand, corners, channel, etc.) are used. This design is more compact than wood, but retains heat worse, and therefore requires additional thermal insulation.

The choice of truss system: hanging and hinged structures

There are two types of roof structures: hanging (spacer) and layered. The choice of system is determined by the type of roof, floor material and natural conditions of the region.

hanging rafters rely solely on the outer walls of the house, intermediate supports are not involved. rafter legs hanging type work in compression and bending. The design creates a horizontal bursting force that is transmitted to the walls. With the help of wooden and metal puffs, this load can be reduced. Puffs are mounted at the base of the rafters.

A hanging truss system is often used to create an attic or in situations where roof spans are 8-12 m, and additional supports are not provided.

Rafters mounted in houses with an intermediate column support or an additional load-bearing wall. The lower edges of the rafters are fixed on the outer walls, and their middle parts are fixed on the inner wall or bearing pillar.

Installation of a single roofing system over several spans should include expansion and layered roof trusses. In places with intermediate supports, layered rafters are mounted, and where they are not, hanging ones.

Features of the arrangement of rafters on different roofs

Gable roof

Gable roof according to building codes, has an angle of inclination up to 90°. The choice of slope is largely determined by the weather conditions of the area. In areas where heavy rainfall prevails, it is better to install steep slopes, and where strong winds- sloping roofs to minimize the pressure on the structure.

Common variant gable roof- design with a tilt angle of 35-45°. Experts call such parameters the “golden mean” of consumption. building materials and load distribution along the perimeter of the building. However, in this case, the attic will be cold and it will not be possible to equip the living room here.

For a gable roof, a layered and hanging truss system is used.

hipped roof

All roof slopes have the same area and the same angle of inclination. There is no ridge run here, and the rafters are connected at one point, so the installation of such a structure is quite complicated.

It is advisable to install a hipped roof when two conditions are met:

• the base of the building is square;
• in the center of the structure there is a bearing support or wall on which it will be possible to fix a rack supporting the junction of the rafter legs.

It is possible to create a hipped roof without a rack, but at the same time, the structure must be strengthened with additional modules - rack puffs.

hip roof

The traditional design of the hip roof suggests the presence rafters(diagonal) directed to the corners of the building. The angle of inclination of the slope of such a roof does not exceed 40 °. Diagonal runs are usually done with reinforcement, since they account for a significant part of the load. Such elements are made from a double board and a durable beam.

The joints of the elements are necessarily supported by a rack, which increases the reliability of the structure. The support is located at a distance of ¼ of the length of the large rafters from the ridge. In place of the gable roof gables, shortened rafters are installed.

The truss structure of a hipped roof may include very long diagonal elements (more than 7 m). In this case, a vertical rack must be mounted under the rafters, which will rest on the floor beam. Sprengel can be used as a support - the beam is located in the corner of the roof and is fixed on adjacent walls. The sprengel farm is reinforced with struts.

broken roof

Sloping roofs are usually created to equip a larger attic. The installation of rafters with this version of the roof can be divided into three stages:

1. Installation of a U-shaped structure - supports for purlins that hold the rafter legs. The base of the structure is floor beams.
2. At least 3 runs are installed: two elements pass through the corners of the U-shaped frame, and one (ridge run) is mounted in the center of the attic floor.
3. Installation of rafter legs.

Gable roof: do-it-yourself installation of rafters

Calculation of the angle of inclination and loads

Of course, the calculation of a gable roof can be done independently, but it is still better to entrust it to professionals in order to eliminate errors and be sure of the reliability of the structure.

When choosing the angle of inclination, it is necessary to take into account that:

• an angle of 5-15 ° is not suitable for all roofing materials, so first choose the type of coating, and then make the calculation of the truss system;
• at an angle of inclination over 45 ° - material costs for the purchase of the components of the "roofing pie" increase.

Snow load limits range from 80 to 320 kg/m2. The design coefficient for roofs with a slope of less than 25° is 1, for a roof with a slope of 25° to 60° - 0.7. This means that if 140 kg of snow cover falls on 1 m2, then the load on the roof with a slope at an angle of 40 ° will be: 140 * 0.7 = 98 kg / m2.

To calculate the wind load, the coefficient of aerodynamic influence and wind pressure fluctuations are taken. The value of the constant load is determined by summing the weight of all components of the "roofing cake" per m2 (on average - 40-50 kg/m2).

Based on the results obtained, we find out the total load on the roof and determine the number of rafter legs, their size and cross section.

Installation of Mauerlat and rafters

Do-it-yourself installation of rafters begins with the installation of a Mauerlat, which is fixed with anchor bolts to the longitudinal walls.

Further construction of the structure is carried out in the following sequence:

Installation of rafters: video

Ways to connect the elements of the truss structure: video

Roof structure

Any low-rise residential building is built in such a way as to obtain a long service life and maximum usable space with minimal material costs. From this point of view, of particular interest are attic spaces, which allow doubling the usable area without any additional changes. On the other hand, the design of roofs, the truss systems of which are designed to create a residential attic, will be more complex.

Today during construction country houses several types of roofs are used:

• Shed. This is the easiest option, since here you can often do without a ridge beam and even without a number of other elements that are required in other cases. Typically, such solutions are used in the construction of utility rooms, outbuildings and garages, but they are also suitable for residential buildings with a small area.

Roofs of this type are among the most economical. They require a minimum amount of roofing material and wood, which is used for roof structures.

• Gable. This is the second most difficult type of roof to create, since only two slopes are required here, and the truss system, as a rule, is no different. Roofs of this type are among the most popular in modern suburban construction, because, despite their simplicity, they do an excellent job with wind and snow loads, and are also suitable for creating an attic.
• Four-slope. This category includes hip, hipped and broken roofs. In the latter case, it is worth mentioning that we are talking about a type of gable roof, which received four slopes due to a break. Such structures are more complicated than the two previous options, however, the aesthetics of the building along with them are higher.
• Gable and multi-slope. Complex rafter attachment points, special device technology and the need for careful calculation are the reasons why such roofs are erected only by professionals. Of course, you can try to build something like this on your own, but only if you are an expert in this field.

The choice of roof type depends on the climate in the region and the wind load. The second point is the angle of inclination of the slopes, which depends on the location of the building, the presence of nearby arrays of buildings or trees, and the climate.

Slope angle

An ideal option for any roof is a design that will require minimal attention from the owner. As a rule, self-cleaning roofs are attractive, as they allow you not to worry about a large amount of snow accumulating.

The accumulation of snow cannot be neglected, since its mass after an intense snowfall can be up to 200 kg per m2, which means that only very strong rafters can withstand such a weight.

An alternative is the construction of the original roof of the type of alpine houses, which have a very large slope of the slopes, often descending almost to the ground. It should be noted that to obtain the effect of snow removal, an angle of 45 degrees is required. In this case, precipitation will roll down the pavement under its own weight.
On the other hand, an increase in the slope of the slopes leads to an increased consumption of roofing and building materials. Moreover, if it is planned to build an attic, then the insulation will be expensive, because the greater the height of the ridge, the higher the consumption of this material. In addition to the cost of a pitched roof, its type also affects the choice of slope. For non-exploited roofs, it is not necessary to use a large amount of insulation, however, increasing the angle of inclination does not always justify itself.

The main feature of an unused roof is a different scheme of the truss system and the absence of a gap between the ceiling and the external protective structure. Usually this flat roofs or those that have a very slight slope. Their main drawback is that during heavy snowfalls, snowdrifts can form, which will not only create a load on the ceiling, but also arrange a “flood” during the thaw.

The type of roofing material will need to be determined in advance, since it must be taken into account when calculating the angle of inclination of the rafters. Typically, flexible materials and bituminous coatings are selected for multi-gable designs. For example, metal tiles, corrugated board or galvanized iron. Other options, such as slate or shingles, are better for roofs that have a simple configuration.

Classical tiles are rarely used today, since they require a fairly large slope angle, ranging from 30 to 60 degrees.

Bituminous materials can be used even at small angles of inclination (from 8 degrees), and the limit value for them is 18 degrees. Metal tiles and asbestos-cement sheets are used at angles from 14 to 60 degrees. We will not dwell on the consideration of roofing materials, since this issue has already been covered on our website.

Spacer and non-spacer layered rafters

These are two types of rafters, one of which is chosen taking into account the shape of the house, the roof and the dimensions of the future structure. Rafter rafters are an option suitable for single or double pitched roofs. Their main feature is that two points of support are used. On the one hand, the rafter leg rests on the roof ridge, and on the other, on the wall of the house.
Non-expanding layered rafters are mounted in such a way as to avoid bursting pressure on the wall of the house. Usually roof structures Roofs are created using one of the following options:

• The rafter leg rests on the Mauerlat. It is hemmed with a bar and fixed by cutting with a tooth. In addition, additional wire insurance is performed. The upper part of the beam is mounted on a ridge run. Fastening is carried out using the sliding support principle.
• The bottom of the rafter is attached through the use of a movable joint. As a mounting point, not only Mauerlat, but also piece bars can be used. The upper part is fixed with a bolt, nails or in another way after it is laid on the ridge run.
• The third option involves the installation of layered rafters with rigid attachment to the run. Nails, studs or other fasteners can be used here.

If the thickness of the rafters, which was initially chosen, turns out to be insufficient, then during the work, supports can be used that are mounted under too long elements in those places where maximum deflection is expected.

Spacer rafters

Laminated rafters are spacer. In this case, it is planned to create such a structure, where a bursting force will be transmitted to the walls of the house. The installation method in this case is the same as in the previous one, however, the fastening of the rafter legs is fixed, so the whole system will receive internal stress. It is worth saying that such an option is a transitional scheme that separates non-thrust layered rafters and hanging ones.

hanging rafters

Such a design of the rafter system will be ideal when it is necessary to cover large spans, the length of which exceeds 7 m. In such a situation, there is only one point of support for the rafter leg - the wall. The upper part of the beam is connected to the counter element located on another slope. There are several options for joints: half a tree, a slotted spike, metal plates.
In order for the rafter legs to be securely fixed, it is necessary to connect them with a puff. Usually it is a strong beam that is attached to the bottom of these elements. Of course, it can be placed higher, but in this case the load will increase, which means that the weight of the beam will also need to be increased. In such a situation, one of the following mounting options for rafter legs can be used:

• The rafter leg is connected to the Mauerlat with the help of an additional gash and is securely held with nails. The second option involves using metal corners. Then the upper parts of the rafters are joined end-to-end, and the lower ones are held by a puff. In this case, the top of the rafter legs can also be pressed against the ridge run, which will rest on the headstock.
• The puffs are set so that the heels of the rafter legs rest with a cut-out tooth on the edges of the puffs, which, in turn, are attached to the Mauerlat. The tops of the rafters are held up with wooden braces.
• Floor beams can be selected for the role of puffs. In this case, their ends should extend beyond the walls by at least 55 cm. The cutting of the socket for the tooth is carried out no closer than 25-40 cm from the edge of the wall.
• In log houses, the rafter leg is fastened to the upper crown through a spike-nest connection. Special metal fasteners, such as sliders, sleds, etc., may also be used. The latter option will allow the structural elements to move and avoid the occurrence of additional stresses.

The puffs themselves can be solid beams or composite elements. Splicing of the bars is carried out in any convenient way, for example, with an oblique tooth, overlapping, etc. Installation of puffs can be performed not only at the level of the heels of the rafters, but also in any other place.

If roof rafters are used, the dimensions of which are more than eight meters, then we recommend creating a structure from a headstock and struts, as well as using racks and crossbars, which help to increase the reliability of the rafter system.

Rafters for different types of roofs

Most simple option is the design shed roof, the rafters of which rest against the walls of the building. The length of these elements cannot exceed 4.5 meters, but there is also a solution for covering large areas. In this case, it is recommended to use props or racks that will hold the extended structure.
Most gable roofs look like twins, but they internal structure can be very different. Today there are four options:

1. A ridge run is used, on which the legs of the rafters rest. The slopes are reinforced by the use of rafter legs, and the run is held by racks. The racks themselves are installed on the bed. The width of this type of roof can reach 10 m.
2. The second option involves the use of rafter legs, the lower parts of which rest against the rack of the ridge run, and the upper parts against the fight (puff) connecting the rafter legs closer to the ridge. In this case, the width of the roof increases to 14 m.
3. There is no ridge run. It is replaced by a beam located under one of the slopes. In addition, a puff, rafter legs and a stand resting on a bed are used. The angles of inclination of the rafter legs vary from 45 to 53 degrees. This option, compared with the previous one, does not give much gain in the width of the roof, however, it is suitable when the supporting wall is not located in the center of the building, but is shifted to the side.
4. In the case when it is required to cover wide buildings, symmetrical structures can be used using two runs located in parallel under the rafter legs of the slopes. Such gable roofs involve the use of two puffs, the upper of which connects the rafters, and the lower one connects the racks and rafter legs. The width of the structure in this case can reach 16 m.

The distance between the rafters is selected taking into account their length and cross section. For example, for a section of 40x150 mm, a step of 60 cm is required, for 50x150 - 90 cm, and for 100x150 - 215 cm.

The hip roof is another option that is common today, which has proven itself well for country houses. It differs in that it does not have pediments, the place of which is occupied by additional slopes - hips. In the general case, the design assumes the presence of a run, and ordinary rafters on the main slopes and hip rafters on the side ones. Hip rafters rest on long diagonal elements where they meet with the upper parts of ordinary rafter legs. For such roofs, it is recommended to use reinforced strapping.
The sloping roof completes the list, as it has a rather complex design. Here, a method is used that involves the creation of a frame for rafter legs, consisting of a horizontal bar and vertical racks, after which the remaining elements are installed. The upper crossbar of the U-shaped frame acts as an attic floor, but the ridge stand also rests on it.

The distance between the rafters of the truss system in this case should be chosen taking into account the load acting on the roof, the thickness of the beam used and the angle of inclination of the slopes.

The main issues related to the construction of the truss system for various kinds roofs, so this material can be used as a short guide to quickly understand the issues of roof construction.

At any pitched roof there is a system with inclined planes (slopes). The selection and calculation of the truss system must be done taking into account the supports necessary for it, as well as the type of roof, dimensions and shapes of the structures to be covered. Having calculated the truss system of a gable roof, you can choose right size rafter legs, as well as provide high strength of the roof.

Types and arrangement of the gable roof truss system

This system should be chosen from the conditions and the number of supports, as well as the distance between them.

For example, layered types of rafters will be supported bearing walls structures (from the outside), as well as on additional. supports inside, if suddenly there will be more than four and a half meters between the main ones. In the lower part, the rafter leg rests on beams that transfer weight between the roof and the wall of the structure. As for the upper end, it is connected to the ridge type of run, as well as to another rafter foot.

The hanging truss system of a gable roof has a puff located at the level where the lower support nodes are located, and maybe higher than they are. There are no intermediate supports. As for the distance between the carriers from the outside, it should be up to six and a half meters. This option refers to a triangular farm, and between them the distance according to the plan is from 1.3 to 1.8 meters.

Coatings

Eternite types of roofing - fibrous or flat asbestos cement sheets. They are cheap and easy to install.

Slate refers to slate roof options, they are made from natural materials layered shales. Slate also includes ondulin and euroslate.

Metal coatings are used to cover residential buildings. They will reliably protect against the effects of the atmosphere, are lightweight and simple in terms of installation work. These include aluzinc, galvanized and corrugated board.

Roll type refers to a soft roof. It has the property of not allowing moisture to pass through, and is very resistant to negative influences environment. They are also easy to install. This includes roofing material, bito-polymer material, membrane roofing.

Some use wood roofing. But very rarely, because they are difficult in terms of installation.

Roof options that transmit light are made of glass, polymer.

We crate

It is the crate - the foundation of the roofs. Made from timber or wooden planks. If a wooden, metal, tiled roof is being equipped, a beam is selected, the cross section of which is:

5 by 5 cm, if the distance between the rafters in the range of one meter is 1.1m).

5 by 6 cm, if the rafter pitch is from 1.2 to 1.3 meters.

6 by 6 if the step is 1.4 or 1.5 meters.

In other cases, boards can be up to 2.5 cm thick.

From wood, log options are used, which are cut down literally on one edge. In order to make layered rafters, a section of a round log with a diameter of 12 to 20 cm is more suitable.

How to calculate the desktop rafter leg?

Between the legs there can be a distance from a meter to one and a half. Their cross section must be determined in accordance with the calculations. For this, the strength and rigidity of structures are recognized. Therefore, you need to find out what is the constant load on the rafters, which includes regular loads and snow, per linear meter.

To carry out calculations, you need to know such data as:

• The step with which the rafter legs are installed
• What is the angle of the roof
• What are the dimensions of the roof

What parameters will be chosen and, in general, many coefficients, depends on the chosen material for the roof and its detailed composition.

It should be borne in mind that there must be a reliable pairing between the runs and the rafter legs. Thanks to this, the walls of structures will not be destructively torn open. If you have wooden structures, they need to be inspected periodically.

Variants of gable roofs are quite common today. But having properly equipped the roof, you will have a strong, beautiful and very durable housing!

To install a gable roof yourself, average carpentry skills and an understanding of its manufacturing technology are enough. All this is easy to understand. It is also necessary to involve an intelligent assistant in the process, because many operations cannot be performed by one person alone. Therefore, many without a doubt take up this work and successfully cope with it.

Do-it-yourself gable roof device

building country house is associated with significant costs. Therefore, many people are looking for options to reduce the cost of this process by using modern materials and technologies. Currently, frame buildings with gable roofs have become very popular. This happens largely for the reason that even a person with minimal knowledge of the construction business, with appropriate preliminary preparation, can carry out such a design.

A gable roof is formed by triangular trusses connected to each other by a longitudinal upper beam (ridge run) and a crate

However, the construction of the roof is a crucial moment that requires a serious attitude. Need to calculate:

• correct angle of inclination;
• rafter length;
• the distance between them;
• ways to connect different parts to each other.

Without experience in the production of such work, you should not take on complex structures, but build small house with a simple gable roof, do it yourself.

Design features of gable roofs

Such a roof consists of two inclined planes located at a certain angle. Gables are arranged along the end walls, which are a vertical continuation of the walls. In shape, they are isosceles or arbitrary triangles, if the slopes are arranged at different angles to the horizontal. In the case of a gable sloping roof, the gables are trapezoid-shaped.

When building a roof, a rafter system is created, which is the supporting element of the roofing pie. The rafter system can be made in the form of hanging rafters if there are no capital partitions inside the building box. If available, a floor frame is arranged when the span is supported by three or more points.

Depending on the configuration of the building, a gable roof can be built according to different schemes.

How to make a gable roof yourself

Depending on the design of the truss system, its main elements may be different, but the main details are present in all options:

1. Rafters are the main load-bearing element of the structure, on which roofing material is mounted through the crate.
2. The ridge run - also called the spinal beam, combines all the rafter legs into a single whole, evenly distributes the load on the Mauerlat.
3. Rack - used in floor structures as an additional support on a major internal partition.
4. Lying - a horizontal bar on which the racks rest, serves to evenly distribute the loads on the Mauerlat.
5. Mauerlat - a support beam between the walls and the upper structure of the building, intended for attaching rafters.
6. Sheathing - flooring from a board 25 millimeters thick for fixing the roof finish.

Regardless of the type of truss system, there are always several basic elements in it.

Roof design

In the process of designing the truss system, it is necessary to optimally place all the elements of the frame in order to ensure a uniform load on the roof over its entire area. The main types of load are:

1. Snowy - occurs under the action of a layer of snow lingering on the roof. At high rates for the construction region, the angle of inclination of the roof is increased so that the snow comes off it as it accumulates.
2. Wind - associated with the force of the impact of the wind. In open, blown places, it is higher. The means of counteracting wind loads is to reduce the angle of inclination of the roof.

Thus, it is necessary to find best option combinations of these indicators with simultaneous exposure to wind and snow. Data on specific loads for the construction region can be found on the Internet.

Gable roofs with a simple design give the house an elegant and holiday look.

Photo gallery: projects of houses with gable roofs

A gable roof allows you to arrange a small attic room on the second floor. The angle of inclination of a gable roof is selected based on the intensity of winds and the average snow load in the construction area.

Calculation of the parameters of a gable roof

Determination of the main characteristics of the roof is necessary already at the stage of designing the foundation to calculate the effect of the total weight of the building on the support base.

Area calculation

With a symmetrical gable roof, it is enough to determine the area of ​​​​one slope and double the result.

The height of the roof depends on the chosen angle of inclination of the slope. Usually it is in the range of 30-45 degrees. In the first case, the height will be half the distance from the projection of the ridge to the Mauerlat axis. Using the Pythagorean theorem and after doing the calculations, we get that the length of the slope for a building of 10x9 m will be 5.05 meters. The slope area is defined as 5.05 x 10 = 50.5 square meters. And the total roof area will be 50.5 x 2 \u003d 101 m 2.

In cases where a gable roof has a non-equilibrium roof, i.e., the axis of the ridge is offset from the axis of the building, the area of ​​\u200b\u200beach slope separately is calculated using the same method and the results are summarized.

However, this calculation does not take into account the area of ​​the roof overhangs. Usually they are 0.5–0.6 meters. For one slope, the overhang area will be 0.5 x 5.05 x 2 + 0.5 x 10 \u003d 4.1 + 5 \u003d 9.1 m 2.

The total roof area will be 101 + 9.1 x 2 = 119.2 m 2.

Most rafter calculations are done according to the Pythagorean theorem, reducing the design to a set of rigid figures - triangles

Calculation of the section of the rafters

The size of the cross section of the rafters depends on several factors:

• the magnitude of the load on them;
• the type of materials used for rafters: log, timber - homogeneous or glued;
• rafter leg length;
• types of wood;
• the distance between the axes of the rafter legs.

All these parameters have long been calculated, and to determine the cross section of the rafter legs, you can use the data below.

Table: rafter section size

With an increase in the installation step of the rafters, the load on each of them increases, which leads to the need to increase the cross section.

Common sizes of the main parts of the truss system:

Determining the angle of inclination

The angle of inclination of the roof slope is determined by the requirements of its finishing coating:

One of the reasons for reducing the angle of inclination is the desire to make the attic or attic space as large as possible. This intention is also the reason for the installation of a sloping roof.

Calculation of the distance between the rafters

This parameter depends on the type of finish coating, or rather, its weight. For the heaviest material, the distance should be minimal, from 80 centimeters. In case of application soft roof, having a small weight, the distance can be increased to 150 centimeters. The calculation of the number of rafters and translations is carried out as follows:

1. The length of the building (10 meters) must be divided by the distance between the rafters, presumably 120 centimeters: 1000 / 120 = 8.3 (pieces). We add 1 to the result, we get 9.3.
2. Since the number of rafters cannot be fractional, the result is rounded up to an integer - 9.
3. The distance between the rafters is finally set: 1000/9 = 111 centimeters.

With this distance, all rafters will be equidistant, and the load from the roof will be distributed evenly.

The length of the rafters is calculated according to the Pythagorean theorem, as already shown above.

Do-it-yourself installation of a gable roof

Work on the installation of the truss system begins with the installation of the Mauerlat.

Mounting the carrier on the wall

Mauerlat is made from high strength wood - oak, larch, etc. In the absence of such materials, pine can be used.

The bar is of standard length - 4 or 6 meters. Therefore, the connection of several parts along the length is inevitable. It is made with a gash of the connected ends “half a tree”, for example, for a bar with a section of 150x150 millimeters, a sample of 75x150 with a length of 300 mm is made. The ends are overlapped. Fastening is carried out with two or four screws M12 or M14 with the installation of washers of large diameter. By the same principle, the bars are connected at the corners. Finished construction is a regular rectangle, which is installed on the upper plane of the wall around the perimeter.

Two beams are spliced ​​by sampling wood on each of them. Then they are bolted together.

The Mauerlat installation technology provides for its placement strictly along the axis of the wall or with an offset in any direction. In this case, you can not place the support beam closer than 5 centimeters from the edge. To increase the service life, the Mauerlat should be installed with waterproofing on the wall surface. Most often, ruberoid is used for this.

Methods for attaching the Mauerlat to the wall

1. Anchor bolt installation. Ideal for monolithic walls. Threaded studs are immured into the wall when it is cast.
2. Wood dowels. They are hammered into the drilled hole. With such fixation, additional metal fasteners are used.
3. Forged staples. They are used with pre-installed embedded parts made of wood.
4. Stud or armature. The pins are immured during the laying of the wall and are removed through the support beam along drilled holes. The diameter of the fasteners should be 12–14 millimeters, the protrusion above the surface of the timber should be 10–14 centimeters.
5. Steel wire. A bundle of two or four wire strands is installed when laying the wall 2–3 rows before its completion. The Mauerlat is tightened using a crowbar. Often used as an additional fastening of the support beam.
6. When constructing a reinforcing belt, fastening to studs or anchor bolts is also used.

The mounting points should be located approximately in the middle between the rafter legs.

Video: installing a Mauerlat on an armored belt

Photo gallery: ways to mount the Mauerlat on the wall

The studs are immured into the wall during its pouring, then a Mauerlat is put on them and fixed with bolts. The wire is also installed at the stage of laying the wall. wall blocks wooden plugs are inserted, in which the staples are then strengthened

Types of roof systems and their installation

The choice of roof truss design is determined by the configuration of the building. If there are no internal capital partitions, a hanging truss system is constructed.

In the presence of capital partitions, it is necessary to use a floor mounting scheme.

Manufacturing of truss pairs

This is the name of a pair of rafter legs connected in an arch with the installation of a spacer element in the form of a puff for a hinged system or a crossbar for a flooring system.

Installation of truss pairs is carried out in three ways:

1. Assembly is done at the top after the translations are installed. They are covered with a flooring made of wood, nailed.
2. The formation of truss pairs is performed on the ground in the immediate vicinity of the house. Only blanks are assembled, which are a rigid triangular structure. The lifting of products is carried out when the rafter pairs for the entire system are ready. For this, it is possible to use lifting devices in the form of a manual or powered winch, which presents certain inconveniences and additional costs. On the other hand, assembly on the ground is much easier and more accurate.
3. The assembly of the roof directly at the installation site is carried out in detail.

With any option, the rafter legs are mounted according to the template, which is the first truss. For higher assembly accuracy of the parts of the next pair, it is desirable to fix them to the previous one with clamps.

When assembling roof systems on the ground, all structures are made according to the template, which is the first manufactured truss. This makes installation more accurate.

The procedure for installing the truss system

Prefabricated roof elements are installed in the following sequence:

Fastening parts of the truss system

For reliable connection of the elements of the roof frame, various auxiliary elements made of galvanized steel up to 1.5 mm thick.

The use of additional fasteners ensures a solid assembly of the truss system

When assembling with the use of additional connectors, labor productivity increases and the strength characteristics of the structure increase.

To connect the elements of the roof of wooden buildings, special fasteners are used. So, the upper joint of the rafters is often connected using a hinge. This is due to the frequent movements of the building, including seasonal ones.

The swivel joint avoids high stresses at the junction of the rafters during seasonal movements of the log house

For the same purpose, sliding fasteners are used on houses made of this material.

Reliable sliding connection of rafters with Mauerlat relieves this node from stress during structural deformations

Video: quick rafters

Before installing the crate, the roof is insulated. For this:

1. The inner crate is stuffed from the side of the attic or attic.
2. The vapor barrier film is stretched.
3. The heater is installed.
4. A moisture-proof film or membrane with one-sided permeability is laid.

Thus, in addition to warming, it creates ventilation system roof space. It starts to work after the installation of the coating.

It is more convenient to lay a layer of insulation from the outside on the inner crate with a vapor barrier coating

Under certain conditions, roof insulation can be done from the inside, it is not so convenient, but you can safely work in all weather conditions. The formation of the roofing cake is carried out in the reverse order. Each layer of insulation as the flooring needs to be strengthened in the openings between the rafters.

Creating a frame gable

Before proceeding with the design of the pediment, you need to arrange the crate and lay the finish coating of the roof.

When forming the crate, the type of future is taken into account roofing. It is made from edged boards with a thickness of 25 millimeters. The crate happens:

1. Solid - boards are stuffed at a distance of 2-4 centimeters from one another. It is applied when using a tile or a soft roof.
2. Sparse - the distance between the boards is 15–25 centimeters. Such a crate is arranged under a metal tile, corrugated board, slate and other similar materials.
3. Rare - the distance between the boards is from 0.6 to 1.2 meters. It is used when the length of the coating sheets is equal to the length of the slope with an overhang. This cover is only made to order.

The crate should be taken out of the gable rafters for the overhang device.

On the front rafter trusses, a frame is mounted for fastening the material of the front finish

Roofing installation

Before laying the crate, the roof is insulated and a moisture-proof layer is laid. Further:

1. Roof covering is being laid. The installation sequence is from bottom to top in order. The straightness of the first row is controlled by a stretched cord.
2. Fastening roofing sheets produced by self-tapping screws using shock-absorbing pads.

When installing a roof finish, you can not save on fasteners, the protective layer must be durable, able to withstand wind and snow loads.

Sheets of metal tiles are laid from the bottom up, starting from the corner of the roof

Installation of gables

The crate of the frame gables is made based on the characteristics of the material intended for the front finish. For this, the following products can be used:

After installing the crate, it is necessary to lay a moisture protection from a polyethylene film 200 microns thick. It can be fixed with building brackets. This work is done outside. On the film, you can sheathe the outer surface with the selected finishing material.

Gables need to be insulated with rolled or tiled heaters. The thickness of the protective layer should be at least 10 cm, and for areas with a cold climate - at least 15 cm. An internal moisture-proof film layer is stretched over the insulation.

On top of it, a crate for the front finish is stuffed, for which bars measuring 50x50 millimeters are used. Finishing of the entire building is carried out simultaneously, after the insulation of the roof.

In the process of facing the pediment, windows are installed if they are provided for by the project, and in some cases doors.

Gable wooden house with a gable roof is most often finished with clapboard

Registration of overhangs

Roof overhangs, both gable and cornice, except for a purely decorative function, are designed to protect walls and foundations from water or snow. Their sizes are usually 50-60 centimeters. Overhangs are made various materials:

• planed board, installed end-to-end or overlapped;
• grooved lining;
• lining block house;
• sheet plastic;
• sheet profiled or smooth metal;
• finished products made of metal or plastic - soffits.

There are several ways to arrange overhangs:

Ventilation holes must be made along the lining. They can be of any size, but large ones must be covered with a fine mesh of any material. This avoids the penetration of birds and harmful insects into the under-roof space. Soffits are sold with ready-made ventilation grilles.

Ventilation is arranged only on cornice overhangs; it is not needed for gable ledges.

When finishing with soffits, the ventilation holes do not need to be drilled - they are already made at the factory

Video: do-it-yourself gable roof device

With the modern abundance of building materials and their quality, you can install a gable roof yourself. The cost savings will be quite significant. But it can also turn into losses if you do not carefully consider every step you take during construction. I wish you success!