Shed roof: necessary calculations. Do-it-yourself shed roof - step by step with a photo - for a house, barn, garage Farm for a shed roof span 6 meters

Using a profile pipe for mounting trusses, you can create structures designed for high loads. Light metal structures are suitable for the construction of structures, the arrangement of frames for chimneys, the installation of roof supports and canopies. The type and dimensions of farms are determined depending on the specifics of use, whether it is a household or an industrial sector. It is important to correctly calculate the truss from the profile pipe, otherwise the structure may not withstand the operational loads.

Canopy of arched trusses

Pipe-rolled metal trusses are labor-intensive to install, but they are more economical and lighter than solid beam structures. A profiled pipe, which is made from a round pipe by hot or cold working, in cross section has the form of a rectangle, square, polyhedron, oval, semi-oval or flat-oval shape. It is most convenient to mount trusses from square pipes.

The farm is a metal structure, which includes the upper and lower belts, as well as the grate between them. The lattice elements are:

• stand - located perpendicular to the axis;
• brace (strut) - installed at an angle to the axis;
• sprengel (auxiliary strut).

Structural elements of a metal truss

Trusses are primarily designed to cover spans. Due to the stiffening ribs, they do not deform even when using long structures on structures with large spans.

The manufacture of metal trusses is carried out on the ground or in production conditions. Elements from shaped pipes are usually fastened together using a welding machine or riveting; scarves and paired materials can be used. To mount the frame of the canopy, visor, roof of a capital building, the finished trusses are lifted and attached to the upper trim according to the markings.

To cover the spans, various options for metal trusses are used. The design can be:

Triangular trusses made of a profile pipe are used as rafters, including for mounting a simple shed canopy. Metal structures in the form of arches are popular due to their aesthetics. appearance. But arched structures require the most accurate calculations, since the load on the profile must be distributed evenly.

Triangular truss for single slope construction

Design features

The choice of the design of canopy trusses from a profile pipe, canopies, truss systems under the roof depends on the calculated operational loads. The number of belts differ:

• supports, the components of which form one plane;
• suspended structures, which include the upper and lower belt.

In construction, trusses with various contours can be used:

• with a parallel belt (the simplest and most economical option, assembled from identical elements);
• single-pitched triangular (each support node is characterized by increased rigidity, due to which the structure withstands serious external loads, the material consumption of trusses is small);
• polygonal (withstand loads from heavy flooring, but are difficult to install);
• trapezoidal (similar in characteristics to polygonal trusses, but this option is simpler in design);
• gable triangular (used for constructing a roof with steep slopes, characterized by high material consumption, there is a lot of waste during installation);
• segmental (suitable for structures with a translucent polycarbonate roof, installation is complicated due to the need to make arched elements with ideal geometry for even distribution of loads).

Outlines of truss belts

In accordance with the angle of inclination, typical farms are divided into the following types:

Calculation basics

Before calculating the farm, it is necessary to choose the appropriate roof configuration, taking into account the dimensions of the structure, the optimal number and angle of inclination of the slopes. You should also determine which belt contour is suitable for the selected roof option - this takes into account all operational loads on the roof, including precipitation, wind load, the weight of people performing work on the arrangement and maintenance of a canopy from a profile pipe or roof, installation and repair of equipment on the roof.

To calculate a truss from a profile pipe, it is necessary to determine the length and height of the metal structure. The length corresponds to the distance that the structure should cover, while the height depends on the designed angle of inclination of the slope and the selected contour of the metal structure.

The calculation of the canopy ultimately boils down to determining the optimal gaps between the nodes of the farm. To do this, it is required to calculate the load on the metal structure, to calculate the profile pipe.

Incorrectly calculated roof frames pose a threat to human life and health, since thin or insufficiently rigid metal structures may not withstand loads and collapse. Therefore, it is recommended to entrust the calculation of a metal truss to professionals familiar with specialized programs.

If it is decided to perform the calculations on your own, you must use the reference data, including the resistance of the pipe to bending, be guided by SNiP. It is difficult to calculate the design correctly without the relevant knowledge, so it is recommended to find an example of calculating a typical farm of the desired configuration and substitute the necessary values ​​\u200b\u200bin the formula.

At the design stage, a drawing of a truss from a profile pipe is drawn up. Prepared drawings indicating the dimensions of all elements will simplify and speed up the manufacture of metal structures.

Dimensional Drawing

We calculate the farm from a steel profile pipe

1. The size of the span of the building to be covered is determined, the shape of the roof and the optimal angle of inclination of the slope (or slopes) are selected.
2. Suitable contours of the metal structure belts are selected, taking into account the purpose of the building, the shape and size of the roof, the angle of inclination, and the expected loads.
3. Having calculated the approximate dimensions of the truss, it should be determined whether it is possible to manufacture metal structures in the factory and deliver them to the site by road, or welding of trusses from a profile pipe will be performed directly on the construction site due to the large length and height of the structures.
4. Next, you need to calculate the dimensions of the panels, based on the indicators of loads during the operation of the roof - constant and periodic.
5. To determine the optimal height of the structure in the middle of the span (H), the following formulas are used, where L is the length of the truss:
   • for parallel, polygonal and trapezoidal belts: H=1/8×L, while the slope of the upper belt should be approximately 1/8×L or 1/12×L;
   • for triangular metal structures: H=1/4×L or H=1/5×L.
6. The angle of installation of the lattice braces is from 35° to 50°, the recommended value is 45°.
7. The next step is to determine the distance between the nodes (usually it corresponds to the width of the panel). If the span length exceeds 36 meters, the calculation of the building lift is required - the back-suppressed bend, which acts on the metal structure under loads.
8. Based on measurements and calculations, a scheme is being prepared, according to which trusses will be manufactured from a profile pipe.

Making a structure from a profile pipe To ensure the necessary accuracy of calculations, use a construction calculator - a suitable special program. This way you can compare your own and software calculations in order to avoid a big size discrepancy!

Arched structures: calculation example

In order to weld a truss for a canopy in the form of an arch using a profile pipe, it is necessary to correctly calculate the design. Consider the principles of calculation using the example of a proposed structure with a span between supporting structures (L) of 6 meters, a step between arches of 1.05 meters, a truss height of 1.5 meters - such an arched truss looks aesthetically pleasing and is able to withstand high loads. In this case, the length of the arrow of the lower level of the arched truss is 1.3 meters (f), and the radius of the circle in the lower chord will be 4.1 meters (r). The value of the angle between the radii: a=105.9776°.

Scheme with the dimensions of the arched canopy

For the lower belt, the profile length (mn) is calculated by the formula:

mn is the length of the profile from the lower belt;

π is a constant value (3.14);

R is the radius of the circle;

α is the angle between the radii.

As a result, we get:

The nodes of the structure are located in the sections of the lower belt with a step of 55.1 cm - it is allowed to round the value up to 55 cm to simplify the assembly of the structure, but the parameter should not be increased. The distances between the extreme sections must be calculated individually.

If the span is less than 6 meters, instead of welding complex metal structures, you can use a single or double beam by bending the metal element under the selected radius. In this case, the calculation of arched trusses is not required, but it is important to choose the right cross-section of the material so that the structure can withstand the loads.

Profile pipe for mounting trusses: calculation requirements

In order for finished floor structures, primarily large-sized ones, to withstand the strength test throughout the entire service life, pipe rolling for the manufacture of trusses is selected on the basis of:

• SNiP 07-85 (interaction of snow load and weight of structural elements);
• SNiP P-23-81 (on the principles of working with profiled steel pipes);
• GOST 30245 (correspondence of the section of profile pipes and wall thickness).

Data from these sources will allow you to get acquainted with the types of profile pipes and choose best option taking into account the configuration of the section and the thickness of the walls of the elements, the design features of the truss.

Canopy for a car from a pipe

Farms are recommended to be made from high quality pipe; for arched structures, it is advisable to choose alloy steel. In order for metal structures to be resistant to corrosion, the alloy must include a large percentage of carbon. Metal structures made of alloy steel do not need additional protective painting.

Useful tips for installation

Knowing how to make a lattice truss, you can mount a reliable frame under a translucent canopy or roof. It is important to take into account a number of nuances.

• The most durable structures are mounted from a metal profile with a section in the form of a square or rectangle due to the presence of two stiffeners.
• The main components of the metal structure are fastened together using twin corners and tacks.
• When joining frame parts in the upper chord, it is required to use I-beam versatile corners, while joining should be done on the smaller side.
• The conjugation of the parts of the lower belt is fixed with the installation of equilateral corners.
• When joining the main parts of metal structures of great length, overhead plates are used.

It is important to understand how to weld a truss from a profile pipe if the metal structure needs to be assembled directly on construction site. If there are no welding skills, it is recommended to invite a welder with professional equipment.

Truss elements welding

Racks of metal structures are mounted at a right angle, braces - at an inclination of 45 °. At the first stage, we cut elements from the profile pipe in accordance with the dimensions indicated on the drawing. We assemble the main structure on the ground, check its geometry. Then we cook the assembled frame, using corners and overlay plates where they are required.

Be sure to check the strength of each weld. The strength and reliability of welded metal structures, their bearing capacity depend on their quality and the accuracy of the location of the elements. The finished trusses are lifted up and attached to the harness, observing the installation step according to the project.

Farms from a profile pipe: manufacturing, how to calculate and weld

Production of farms from a profile pipe. How to correctly calculate the design and weld. The main types of forms outlines of farms.

Metal supporting roof structure

The farm is hanging structure, which consists of the upper and lower belts, braces and racks, which is part of the general rafter system of the roof of the house. Today it can be made from different material, but metal structures are becoming increasingly popular.

The truss truss can be made of various materials, but metal structures are becoming increasingly popular.

The construction of a metal roof is carried out according to modern technology, which today is considered optimal for a wide variety of buildings. frame houses made of lightweight metal structures are resistant to various external conditions, they are durable and reliable.

The calculation of such truss systems is carried out using special programs that take into account numerous factors, which makes the entire structure very reliable.

Benefits of using metal trusses

Metal trusses used to be used wherever high structural strength was needed, today the advantage of using just such structures is also used for private construction, and not only during the construction industrial enterprises. Today, metal trusses are in demand, which can be divided into two groups: spatial and flat.

Flat structures are distinguished by the fact that each metal rod is located in only one plane. Spatial structures form bars that perfectly withstand loads from all sides. This is similar to the device of a tower crane, which is resistant to fairly strong, continuous loads during use.

The main elements of a metal truss are a rafter belt and gratings, the belt accounts for longitudinal force and the moment, on the lattice - the transverse force. The space that is located between them is called the panel, the free gap between the trusses is the span, the space between the axes of the belts is the height.

Types of metal trusses.

The metal trusses used today can be very different, which greatly distinguishes them from others. They differ in the form of belts, spans, sizes, manufacturing schemes. So, static trusses can be frame, beam, cable-stayed, arched. Beams in this case are distinguished by a more economical consumption of materials, less weight than the rest, they can be used for the manufacture of structures that need resistance to large, constant loads. Arched ones are used to create unusual attractive roof shapes, but during their construction, the consumption of building materials is slightly increased.

In addition, combined schemes are used, polygonal, segmented, triangular, trapezoidal, with parallel belts. All of them are distinguished by high strength, low weight, stability. The high quality of the installation of the truss system is ensured by the fact that any calculation for such a design is carried out using special programs.

As materials for the manufacture of metal trusses, lightweight galvanized metal profiles (the so-called LSTK, that is, light steel thin-walled structures) are used, fastened with self-tapping screws and special bolts, or special steel beams for which welded joints are used.

Features of the calculation of metal structures

Calculating metal roof trusses is a procedure that requires special knowledge. Typically, such calculations are performed by designers using special programs, taking into account numerous factors. This calculation makes metal structures as reliable as possible. When calculating the truss system, it is necessary to take into account the following factors:

• constant loads on the roof (the weight of the roofing material and the truss system itself);
• additional loads (wind, snow, the weight of people who rise to the roof surface for repairs, etc.);
• periodic and special loads (presence of hurricanes, seismic loads, other random factors).

The scheme of snow load on the roof.

Snow load is calculated by the formula: N= Q*k

Q is the amount of precipitation per square meter in winter period;

k is the slope angle coefficient.

Wind loads should also be taken into account, which include data on the maximum wind speed in the area, the number of storeys of the building, design features roofs, its areas.

The exact calculation of metal trusses can only be done by a specialist, you should not try to do it yourself!

Types of metal trusses

1. Universal for industrial buildings: single-pitched and double-pitched. The spans for them are unified, they are taken as multiples of 3 m, they can be 18, 24, 30 meters. The angle of inclination of the braces is usually 45-50°, the overall shape ensures the rigidity of the structure, the ability to withstand heavy loads.
2. Metal trusses with additional trusses are used in non-purlin structures for large-panel reinforced concrete slabs with a width of 1.5 m. This makes it possible to reduce the weight of the farm by 4-6%.
3. Triangular trusses are used for residential buildings when the roof slope is planned to be quite steep.

Rafter metal structure: installation work

Installation of metal roof trusses should be carried out only by professionals. All fastenings are carried out only according to the project. These are bolted and welded fasteners (for various types material). Installation rules depend not only on the type of structure, but also on its specification; with a span of more than 4.5 m, it is recommended to pre-install additional supports for any type of truss.

The choice of coating for depending on the angle of the roof

All metal rafters, or rather their appearance and design, depend largely on the angle of the roof slope. Consider the options for the device truss systems:

1. The slope is 22-30 degrees. When installing a roof with a slope of 22-30 °, you can use coating options such as eternite, iron or slate. Farms at the same time make a triangular shape, their height should be one third of the span length. The weight of such a truss will be relatively small, for supports you can use the outer walls, which are erected at a low height for the attic. If the span is 14-20 m, then each half of the truss should have an even number of panels, the panel length should be 1.5-2.5 m. For the specified span, the optimal number of panels is eight;

For large buildings, where the span is from 20 to 35 meters, it is necessary to use the so-called Polonso trusses, that is, a metal structure that consists of two triangular trusses connected by puffs. This makes it possible to remove the long braces for the middle panels to reduce weight. The upper belt in this case must be divided into 12-16 panels with a length of 2-2.75 meters for each. The calculation for filing the ceiling should take into account the presence of a tightening of 4-6 panels, which is attached to the nodes of the upper belt.

1. Slope 15-22°. With such a roof slope, the calculation of metal trusses provides for a structure height of 1/7 of the span length, while the lower chord is made broken, which makes it possible to reduce weight by 30% compared to a conventional triangular truss. The length of one span should not be more than 20 meters;
2. Slope from 6 to 15°. For roofs with a slight slope, trapezoidal trusses are used with a height of 1/7 to 1/9. In the case when the ceiling is not suspended, you can use braces made in the form of a triangular lattice. The walls of the attic for the installation of such a system must have the proper height, or a roof is designed that has fractures at the supports. In this case, the panels of the lower chord must be equal to the size of the panels of the upper chord. The calculation is carried out taking into account the fact that the length itself should be 1.5-2.5 m, racks are added to all braces. In order for the structure not to be heavy, a lattice is used.

The use of metal for the manufacture of truss systems is not such a novelty. Such structures have been known since the end of the 19th century, although they were used extremely rarely, mainly for the construction of palaces and temples. Today, metal has gained a second life; reliable and very durable buildings, residential buildings, and industrial facilities are made from it.

The calculation of such structures should be carried out only by specialists, for this there are special programs. The fastenings of metal trusses can be different, as well as the material of manufacture: these are welded steel structures, lightweight galvanized, which are fastened with self-tapping screws and bolts. The type of trusses themselves and the dimensions largely depend on what slope of the roof will be made, what loads are expected.

Metal roof truss

The metal roof truss is used not only in the construction of industrial buildings, but also in private houses. It has long established itself as a reliable roofing structure.

Metal roof trusses: roof support structure

Trusses are structural elements that, having perceived the load in the span, transfer it to the supports. Metal roof trusses have the form of a lattice through structure, made of rectangular rods, "assembled" with each other into nodes. The choice of their design for a particular roof determines the location attic floor, roof slope and required span.

Metal roof trusses are mainly made from steel profiles, more often from a corner. For heavier structures, the profile has a T-section or an I-section, and for hydraulic structures - a round one, profile pipe. Steel truss truss is widely used in structures for covering and overlapping buildings, often with a span width of more than 24 m.

Metal structure

The strength and rigidity of these elements of the supporting structure is provided by their shape. Classic variant a metal truss consists of rods - two parallel and another between them, welded in a zigzag manner. Thanks to this arrangement, even with a relatively small consumption of material, the resistance of the metal structure is increased.

Main structural elements:

• belts, upper and lower, forming a contour;
• lattice assembled from braces and racks.

Nodal connection of elements is performed by direct adjoining one to the other. The lattice rods are fixed to the belts either by welding or by means of shaped elements. In addition to rafters, there can also be rafters. They are used as supports for load-bearing structures and floors, if the distance between the columns exceeds the step of the beams or the columns have an unequal step.

Types: by belts and lattices

They are classified according to the geometry of the belts and the type of lattice.

According to the belt

• with parallel belts - have enough design advantages. The greatest repeatability of parts, associated with equal lengths of rods for chords and gratings, the same scheme of nodes, a minimum number of chord joints, makes it possible to unify designs, which makes it possible to industrialize their production. They are optimal for soft roofs.

• trapezoidal (single-pitched) - in conjunction with columns, it makes it possible to arrange rigid frame assemblies that increase the rigidity of the building. In the middle of the span, there are no long rods on the lattice of these trusses. They do not require large slopes.
• polygonal - suitable for heavy structures used for large spans, while they provide significant savings in steel. The polygonal outline for light options is irrational, since the slight savings are not commensurate with the complexity of the design.

• triangular - they are usually used for steep roofs or, based on the operating conditions of the building or the type of roofing material. Although they are simple in execution, they have certain design flaws, for example, the complexity of a sharp support unit, increased consumption of materials in the manufacture of too long rods in the central part of the lattice. The use of triangular systems is mandatory in some cases, for example, in buildings where it is necessary to ensure, on the one hand, a significant and uniform influx of natural light.

Lattice systems

• triangular - the most effective in the case of parallel belts and a trapezoidal outline, it is possible to use them in a system with a triangular outline;
• diagonal - braces, the longest elements, should be stretched, while the racks, on the contrary, should be compressed. Such a lattice, compared with a triangular one, is more laborious and has a greater consumption of material;
• special - trussed, cross and others.

Calculation of a triangular farm and its features

The calculation takes into account the requirements of SNiP for "Steel structures" and "Loads and impacts". Competently calculate truss systems from metal is possible only with special knowledge. This takes into account numerous factors, so designers, as a rule, turn to the help of special programs when calculating.

What is the basis of calculations triangular truss: example

Trusses are under the constant influence of loads such as the weight of the roof, lanterns, hanging drainage systems, fans, own weight of the supporting structure and others. The temporary loads include the pressure of wind, snow, the weight of people on the roof, suspended transport.

Special or periodic loads are also taken into account, such as seismic, hurricane, etc.

Fabrication and connection of elements

• Assembly. They are assembled in stages from parts on tacks.

• A bunch of belts is produced using one or two paired corners:

• the upper belts are made of unequal two corners having a tee section, docking is carried out on the smaller sides;
• for the lower belts, respectively, isosceles corners are used.

• If the element is long, use connecting and patch plates. In the case of loads formed within the boundaries of its panels, paired channels are used.
• The angle of installation of the braces is 45°, and the racks are 90°. For their manufacture, isosceles corners are used, fastening the elements by means of plates. The corners in the section are either cruciform or tee.
• Fully welded systems are made using brands.

• Welding. When the assembly on tacks is completed manually or semi-automatically, welding is performed, after which each seam is cleaned.
• Coloring. At the final stage, holes are drilled in the truss structure and coated with anti-corrosion compounds.

Some device rules

The type and design of metal rafters largely depends on the slope of the roof. Consider the relationship between the roof slope and the arrangement of truss systems:

• 6–15° – trapezoidal truss, height 1/7–1/9 of its length. To equip the attic, either its walls must have an appropriate height, or the projected roof must have fractures at the supports. The size of the panels of the lower and upper chords must be the same. To make it easier, use a grid.
• 15–22 ° - the height of the metal structure is equal to 1/7 of the length, the lower belt should be broken - this allows you to reduce weight compared to the usual triangular order of 30%. In this case, one span in length should not exceed 20 m.
• 22–30° – triangular system, height 1/3 of length. Since its weight is relatively small, external walls erected to a small height can serve as a support.

Series 1.263.2-4. Issue 1. Trusses with spans of 18, 21 and 24 m from rolling corners. KM drawings(7.1 MiB, 368 hits)

1.263-2-4.1KM-4 Truss diagrams with node marking. Breakdown of farms into shipping marks

1.263-2-4.1KM-5 Diagrams of the arrangement of trusses with a span of 18 m and connections

1.263-2-4.1KM-6 Diagrams of the arrangement of trusses with a span of 21 m and connections

1.263-2-4.1KM-7 Layout diagrams of trusses with a span of 24 m and ties

1.263-2-4.1KM-8 Scheme of trusses with marking of elements

1.263-2-4.1KM-9 Truss assortment with span L=18 m and H=1.2 m

1.263-2-4.1KM-10 Truss assortment with span L=18 m and H=1.8 m

1.263-2-4.1KM-11 Truss assortment with span L=21 m and H=1.8 m

1.263-2-4.1KM-12 Truss assortment with span L=24 m and H=1.8 m

1.263-2-4.1KM-13 Schemes of vertical connections B-1, B-2

1.263-2-4.1KM-14 Node 1

1.263-2-4.1KM-15 Knot 2.3

1.263-2-4.1KM-16 Node 4

1.263-2-4.1KM-17 Knot 5

1.263-2-4.1KM-18 Node 6

1.263-2-4.1KM-19 Node 7

1.263-2-4.1KM-20 Knot 8

1.263-2-4.1KM-21 Node 9

1.263-2-4.1KM-22 Knot 10

1.263-2-4.1KM-23 Node 11

1.263-2-4.1KM-24 Knot 12-15

1.263-2-4.1KM-25 Instructions for the calculation of welded joints of truss units

1.263-2-4.1KM-26 Marking holes along the upper chords of trusses for fastening ties

1.263-2-4.1KM-27 Layout of reinforced concrete slabs and details of their welding to truss belts

1.263-2-4.1KM-28 Specification of steel trusses with a span of 18 m

1.263-2-4.1KM-29 Specification for steel trusses with a span of 21 m

1.263-2-4.1KM-30 Specification of steel trusses with a span of 24 m

Approved: State Committee for Civil Engineering and Architecture under Gosstroy of the USSR 10/13/1982

Series 1.263.2-4. Issue 2. Farms with a span of 27, 30 and 36 m from rolling corners. KM drawings(8.8 MiB, 129 hits)

1.263-2-4.2KM-2 Truss schemes with node marking. Breakdown of farms into shipping marks

1.263-2-4.2KM-3 Layout of trusses with a span of 27 m and connections

1.263-2-4.2KM-4 Diagram of the arrangement of trusses with a span of 30 m and connections

1.263-2-4.2KM-5 Layout of trusses with a span of 36 m and connections

1.263-2-4.2KM-6 Truss diagrams with element marking

1.263-2-4.2KM-7 Assortment of trusses with span L=27 m; H=1.8 m

1.263-2-4.2KM-8 Truss assortment with span L=27 m; H=2.1 m

1.263-2-4.2KM-9 Truss assortment with span L=30 m; H=1.8 m

1.263-2-4.2KM-10 Truss assortment with span L=30 m; H=2.1 m

1.263-2-4.2KM-11 Truss assortment with span L=36 m; H=2.1 m

1.263-2-4.2KM-12 Truss assortment with span L=36 m; H=2.4 m

1.263-2-4.2KM-13 Schemes of vertical connections B-1, B-2; B-3

1.263-2-4.2KM-14 Node 1

1.263-2-4.2KM-15 Knot 2.3

1.263-2-4.2KM-16 Node 4

1.263-2-4.2KM-17 Node 5

1.263-2-4.2KM-18 Node 6

1.263-2-4.2KM-19 Node 7

1.263-2-4.2KM-20 Knot 8

1.263-2-4.2KM-21 Knot 9

1.263-2-4.2KM-22 Knot 10-13

1.263-2-4.2KM-23 Instructions for the calculation of welds in truss nodes

1.263-2-4.2KM-24 Marking holes along the upper chords of trusses for fastening ties

1.263-2-4.2KM-25 Layout of reinforced concrete slabs and details of their welding to truss belts

1.263-2-4.2KM-26 Specification of steel trusses with span L=27 m; H=1.8 m

1.263-2-4.2KM-27 Specification of steel trusses with span L=27 m; H=2.1 m

1.263-2-4.2KM-28 Specification of steel trusses with span L=30 m; H=1.8 m

1.263-2-4.2KM-29 Specification of steel trusses with span L=30 m; H=2.1 m

1.263-2-4.2KM-30 Specification of steel trusses with span L=36 m; H=2.1 m

1.263-2-4.2KM-31 Specification of steel trusses with span L=36 m; H=2.4 m

Accepted: MADI of the Ministry of Higher Education of the USSR (Moscow Automobile and Road Institute)

Accepted: President of Russian Federation

Accepted: CITP Gosstroy of the USSR

Approved: State Committee for Civil Engineering and Architecture under the Gosstroy of the USSR 01/04/1983

Series 1.263.2-4. Issue 3(11.6 MiB, 80 hits)

1.263-2-4.1KM-2 Truss diagrams with node marking. Breakdown of farms into shipping marks

1.263-2-4.1KM-3 Layout of trusses with a span of 18 m, purlins and ties

1.263-2-4.1KM-4 Layout of trusses with a span of 21 m, girders and ties

1.263-2-4.1KM-5 Layout diagrams of trusses with a span of 24 m, purlins and ties

1.263-2-4.1KM-6 Layout diagrams of trusses with a span of 27 m, purlins and ties

1.263-2-4.1KM-7 Layout diagrams of trusses with a span of 30 m, runs and ties

1.263-2-4.1KM-8 Layout diagrams of trusses with a span of 36 m, purlins and ties

1.263-2-4.1KM-9 Scheme of trusses with marking of elements

1.263-2-4.1KM-10 Truss assortment with span L=18 m; H=1.2 m

1.263-2-4.1KM-11 Truss assortment with span L=18 m; H=1.8 m

1.263-2-4.1KM-12 Truss assortment with span L=21 m; H=1.8 m

1.263-2-4.1KM-13 Truss assortment with span L=24 m; H=1.8 m

1.263-2-4.1KM-14 Truss assortment with span L=27 m; H=1.8 m

1.263-2-4.1KM-15 Truss assortment with span L=27 m; H=2.1 m

1.263-2-4.1KM-16 Truss assortment with span L=30 m; H=1.8 m

1.263-2-4.1KM-17 Truss assortment with span L=30 m; H=2.1 m

1.263-2-4.1KM-18 Truss assortment with span L=36 m; H=2.1 m

1.263-2-4.1KM-19 Truss assortment with span L=36 m; H=2.4 m

1.263-2-4.1KM-20 Schemes of vertical connections V-1…V-4

1.263-2-4.1KM-21 Node 1

1.263-2-4.1KM-22 Knot 2.3

1.263-2-4.1KM-23 Node 4

1.263-2-4.1KM-24 Node 5

1.263-2-4.1KM-25 Node 6

1.263-2-4.1KM-26 Node 7

1.263-2-4.1KM-27 Knot 8

1.263-2-4.1KM-28 Node 9

1.263-2-4.1KM-29 Knot 10

1.263-2-4.1KM-30 Node 11

1.263-2-4.1KM-31 Knot 12-15

1.263-2-4.1KM-32 Instructions for the calculation of welded joints of truss units

1.263-2-4.1KM-33 Marking holes along the upper chords of trusses L = 18-24 m for fastening ties

1.263-2-4.1KM-34 Marking holes along the upper chords of trusses L = 27-36 m for fastening ties

1.263-2-4.1KM-35 Tables for the selection of grades of purlins and the profile of the dimensions of the flooring

1.263-2-4.1KM-36 Specification of steel trusses with span L=18 m; H=1.2 m; H=1.8 m

1.263-2-4.1KM-37 Specification of steel trusses with span L=27 m; L=24 m; H=1.8 m

1.263-2-4.1KM-38 Specification of steel trusses with span L=27 m; H=1.8 m; H=2.7 m

1.263-2-4.1KM-39 Specification of steel trusses with span L=30 m; H=1.8 m; H=2.1 m

1.263-2-4.1KM-40 Specification of steel trusses with span L=36 m; H=2.1 m

1.263-2-4.1KM-41 Specification of steel trusses with span L=36 m; H=2.4 m

Approved: State Committee for Civil Engineering and Architecture under Gosstroy of the USSR 05/06/1983

Series 1.263.2-4. Issue-4. Farms with a span of 15, 18, 21, 24, 27 and 30 m from welded bent-closed profiles (with reduced height)(6.8 MiB, 139 hits)

1.263-2-4.4-01KM Truss schemes with node marking. Breakdown of farms into starting marks

1.263-2-4.4-02KM Plans of arrangement of trusses with a span of 15.18 m and ties

1.263-2-4.4-03КМ Plans of arrangement of trusses with a span of 21.24 m and connections

1.263-2-4.4-04КМ Plans of arrangement of trusses with a span of 27.30 m and connections

1.263-2-4.4-05KM Truss schemes with element marking

1.263-2-4.4-06KM Assortment of trusses with a span of 15.18.21 m

1.263-2-4.4-07KM Assortment of trusses with a span of 24 m

1.263-2-4.4-08KM Assortment of trusses with a span of 27 m

1.263-2-4.4-09KM Assortment of trusses with a span of 30 m

1.263-2-4.4-10KM

1.263-2-4.4-11KM Node 1.2

1.263-2-4.4-12KM Node 3…8

1.263-2-4.4-13KM Truss support units (options)

1.263-2-4.4-14КМ Fragments of the flooring plan with the location of fasteners

1.263-2-4.4-15KM Permissible design load on decking

1.263-2-4.4-16KM

1.263-2-4.4-17KM Truss welds

1.263-2-4.4-18KM Parts D-1…D-3

1.263-2-4.4-19KM Specification of steel trusses with a span of 15,18,21 and 24 m

1.263-2-4.4-20KM Specification of truss steel with a span of 27 and 30 m

1.263-2-4.4-21KM Bill of materials consumption

Approved: State Committee for Civil Engineering and Architecture under Gosstroy of the USSR 03/29/1984

Metal roof trusses: design calculation, manufacturing

Metal roof trusses are a lightweight metal structure with special strength. Unlike beams, solid in design, they are lattice.

Shed roof is one of the simplest designs. It is often used in the construction of various outbuildings.

The main advantages of a roof with one slope are the ease of its construction and the minimum consumption. building material.

To truss system pitched roof was reliable and durable, it is necessary to take into account all the nuances in its construction.

The developed project should reflect:

• Section, pitch and dimensions of elements;

• Schemes for the manufacture of nodes of the roof structure.

If there are difficulties in performing the calculations, it is advisable to seek the advice of specialists.

Installation of a roof truss system

The construction of a single-pitched roof truss system consists of several stages. Each of them will be considered separately.

Laying mauerlat beam

The first step is to lay the Mauerlat beam on the long walls of the building. It will evenly distribute the load from the roof to the walls of the building. The greater the angle of the roof slope, the more massive the Mauerlat should be.

If a metal tile is used as a roofing material, then a load-bearing beam with a cross section of 100 × 100 mm is used. When using corrugated board, it is possible to lay a Mauerlat beam with a cross section of 80 × 80 millimeters.

Mauerlat is made from a flat, dry timber impregnated with an antiseptic solution. A layer of roofing material is laid on the load-bearing wall, and then the Mauerlat beam itself is mounted. The installation of the beam is carried out strictly according to the level by means of anchor bolts. The distance between the anchors should be between 80 and 100 cm.

Mauerlat processing

The overhang of the rafter over the roof overhang should be 30 to 40 centimeters on each side. Its value depends on the angle of inclination. The greater the slope angle, the greater the overhang from the upper side of the roof and less from the bottom. The step of the rafters of a pitched roof under corrugated board and metal tiles is 120 centimeters.

This value is reduced to 100 centimeters if the width of the roof is more than six meters. In order for the rafter structure to be strong, it is necessary to cut the rafter board into a fixed Mauerlat beam. All cutouts must be the same size. They should slightly exceed the width of the rafters.

You can also immediately note the size and location of the cuts on the Mauerlat. Notches are best done with a hand saw. In this case, they will be accurate and accurate. The wood in the grooves formed between the cutouts must be removed with a hammer and chisel.

Rafter installation

When installing the rafters of a pitched roof, you must first cut them to size and treat with an antiseptic. Then they are laid in the extreme grooves on both sides of the roof. Several strings are pulled between the laid rafters.

With the help of these strings, the constancy of the slope is assessed, and only after that the extreme rafter legs are fixed. To fix the rafters, carpenter's nails with wide hats are used. One or two nails should be used for each joint. When installing the remaining rafters, they are guided by stretched twine.

If the span is large, then the middle of the rafters must be reinforced with triangular slopes or additional supports. After installing the rafters of a shed roof, you can begin to manufacture the crate and lay the selected roofing material.

In this article I want to tell you how a simple shed roof is built. Why did I call it simple? Just because her truss truss consists only of rafters. No racks, struts, braces, etc. there is no. This type of roof is most often used in the construction of small garages, sometimes baths, various outbuildings to the house, any outbuildings, etc.

In general, when you read about shed roofs in literature or the Internet, you usually see such a statement - they are supposedly the cheapest, easiest to build and reliable.

Regarding cheapness and simplicity, I absolutely agree, but about reliability, I’m ready to argue.

Of course, maybe I live in the wrong climate zone, but in my practice I have never seen a roof that has two or more slopes (for example, hip, tent, etc.) collapse on a private low-rise building. All the collapses that have ever occurred have been on shed roofs. The reason for them is almost always snow loads plus the weight of people who work on the roof (for example, throw off the same snow).

So why is this happening. I think everything is simple here. Often, developers do not take a very serious and deliberate approach to the construction of a pitched roof. Basically, one of three mistakes is made, or several at once:

An unacceptably small slope angle is made;

As rafters, boards with an unsuitable section are used;

Too much step is taken between the rafters.

How to avoid these mistakes, we will now understand using the example of building a shed roof over a garage.

Let's say we have a box of foam concrete blocks with a wall thickness of 30 cm. Its dimensions are shown in Fig. 1.

Picture 1

Having started laying blocks, we must already decide on the angle of inclination of the roof slope. What should be followed here?

I think many people know that for each roofing there is a minimum angle of inclination of the slope at which it can be used. These values ​​are presented in table 1., compiled on the basis of SNiP II-26-76 * (“Roofs” - updated version of 2010):

Table 1.

I am sure some of you who have already studied similar tables on the Internet will be a little embarrassed when you see such numbers. I want to tell them about a little confusion that has arisen on various construction sites due to the banal inattention of their authors. Often, when compiling such a plate, they take the numbers from the above-mentioned SNiP II-26-76 *, but do not notice that in this document the angles are indicated in percentages (%), and not in degrees, as we used to measure them from school. I will not now explain how to convert percentages to degrees. There is this information on the network (there are also formulas, there are also tablets). Basically, we don't need it.

Now another note. Each manufacturer of any roofing (whether it be metal or bituminous tiles, etc.) sets the minimum angle of inclination of the roof for its products. It is indicated in the installation instructions. For example, for different manufacturers of metal tiles, you can see numbers at 14 °, and at 16 °, etc. Often these numbers are higher than those determined by SNiP and indicated in Table 1.

But that's not all. All the figures given above characterize the angle of inclination of the roof, at which this roofing will not overflow water between adjacent elements under certain weather conditions. And these conditions in our country are very, very diverse. So snow loads differ significantly in different climatic zones. And wind turbines in general may differ within one locality, depending on the location of your building relative to others.

Snow loads affect the possible deflection of the truss system, which changes the geometry of the roofing. In addition, with a large amount of snow, the so-called “snow bag” often forms on the roof (see Fig. 2):

Figure 2

Strong winds can also push rain water through the joints of the roof elements.

I have looked at many various sources, but nowhere did he find a specific dependence of the minimum angle of inclination of the roofing on the climatic conditions in the region. As I understand it, no one brought it out. Everyone uses values ​​based on previous years of experience. I can say that for shed roofs, in middle lane In Russia, it is usually not recommended to make the slope angle less than 20 °. We will also build on this value.

So, let on our garage (Fig. 1) we decided to make the angle of inclination of the ramp equal to 20 °. We will cover with corrugated board. Now we need to decide how high the walls need to be laid out. In this case, we make a low wall with a height of 2.4 meters. This value is chosen in each case individually, depending on your personal preferences and the features of your building. The height of the opposite wall is determined by a simple formula:

H in \u003d H n + V × tg α,

where H in - the height of the high wall;

H n - the height of the low wall;

B - the width of the building (garage);

α is the angle of inclination of the slope.

In our case, H in \u003d 2.4 + 4.8 × tg 20 ° \u003d 4.2 m. (Slightly rounded up).

Now you can start laying the foot of the garage. Please note that the last row is not laid at the high wall. Why will become clear later.

STEP 1: We begin the construction of the roof with the installation of a Mauerlat. As a Mauerlat, we use a bar 100x150 mm (Fig. 3). It is placed flush with the interior walls. Notice how the sloping wall is laid out.

Figure 3

Also, instead of a beam, you can use two 50x150 mm boards sewn together with nails. I wrote about such an example in an article about installing a Mauerlat. It describes several ways to fix the Mauerlat on the wall. In addition to them, I want to show you one more, which we sometimes use when building a roof on gas and foam concrete walls, when the customer does not want to make an armored belt (Fig. 4):

Figure 4

A reinforced roofing corner 90x90 is used here. We fasten it to aerated concrete using two ʺGBʺ dowels with a diameter of 14 mm. They keep great. We put such corners on the Mauerlat after about 80-100 cm.

Please note that a roofing material must be placed under the Mauerlat so that there is no contact between wood and aerated concrete and metal. In all subsequent figures, the roofing material is simply not shown, but its presence is mandatory.

STEP 2: We begin the installation of rafters. To do this, first of all, we need to decide on their cross section and the step between them. In this we will again be helped by the program described in the article “Rafter system. Calculation of rafters and floor beamsʺ ().

I want to clarify again. I am not the author of this program. But I always use it, for lack of anything else (more or less understandable). I have full confidence in the strength of the roofs that we have already built. This confidence comes during the construction process, when you climb the rafters yourself and when you inspect the rafter system a few years after the construction of the house (I have such opportunities).

The program is certainly not perfect and sometimes you have to make some assumptions yourself. Therefore, do not judge strictly. The main thing is that all these assumptions work towards increasing the margin of safety of rafters and beams.

Let's go back to our garage. Let's take the Moscow region as an example. The sum of snow and wind loads will be 196 kg/m 2 . Where this figure comes from, I described in detail in the article (link above). I think it makes no sense to repeat. By the way, just here I make one assumption in the calculation. In the program, when entering the initial data, the value of only the snow load is requested (Fig. 5). There is no column for entering the wind load at all. Therefore, I simply add it to the snow one, although I know that it acts in the other direction (snow - from above, wind - from the side).

Figure 5

We entered the pitch of the rafters 0.5 meters. The calculation result (in the Sling.1 tab) is shown in Figure 6. Boards with a section of 50x200 mm were selected for the rafters. Of course, the step is small, but where to go. If we take it equal to 0.6 meters, then this section does not pass the calculation. Of course, you can take, for example, a bar 150x100 as a rafter, then the minimum step will change. Here you can already improvise. I am used to working with boards of either 50x150 or 50x200 mm.

Figure 6

By the way, in the figure, the distance between the supports (4.2 meters) is the internal width of our garage.

Having determined the cross section, we mark the cuts of the rafters. We take a board 50x200 mm of a suitable length and put it on the Mauerlat (see Fig. 7). It should hang from the walls with a margin (we got 53 cm), so that after the final trimming, the cornices will turn out to be 40-50 cm wide.

Figure 7

Now, using either a square or a tape measure with a small level, we mark the lower and upper cuts. In this case, we make the width of the cut equal to the width of the Mauerlat - 150 mm. The depth of the gash in this case will be 48 mm (see Fig. 8). Such exact values ​​are given to me by the program in which I draw a three-dimensional model of the roof (Google SketchUp). IN real work, of course, there will not be such accuracy to the millimeter, but it is not particularly needed there.

In other articles, when considering roofs with large slope angles, such cuts are made not based on the width of the mauerlat, but based on the maximum allowable cut depth. It is usually 1/3 of the height of the rafter section. Now we have 1/3 of 200 mm - this is 66 mm. We fit into this value. And making the width washed down more than the width of the Mauerlat makes absolutely no sense.

Figure 8

So, we got a template according to which we make all subsequent rafters and install them (see Fig. 9):

Figure 9

The end rafters do not touch the sloping walls. You can see this in the figure above. The gap is about 5 cm.

STEP 3: We manufacture and install cornice fillies (see Fig. 10):

Figure 10

We make them from boards of the same section as the rafters. On an inclined wall, before installing the filly, we roll out the roofing material. It is not shown in the figure.

The sequence is like this. First, we put two extreme fillies and pull the lace between them (see Fig. 11):

Figure 11

Then, with a step of about 0.8-1 m, we install the rest (see Fig. 12).

Figure 12

It is enough to fix the filly with 2 nails (120 mm) hammered into the end through the rafters. The end caps can be fastened with roof angles directly to the sloping wall.

STEP 4: We install end (wind) boards (see Fig. 13):

Figure 13

We use inch boards 25x200 mm.

Also, we need to lay the Mauerlat on a high wall (see Fig. 14). This can be done either with aerated concrete or ordinary brick. Again, the tree must be separated from other material by a layer of roofing material.

Figure 14

STEP 5: We hem the cornices from below. This is done depending on final finishing roofs. The cornices are either sewn up completely, or, as in our case, only belts are hemmed for subsequent siding trim (see Fig. 15):

Figure 15

It is enough to use boards 25x100 mm as belts.

STEP 6: Now we make a crate (see Fig. 16):

Figure 16

The required section of the boards of the crate can be determined in the program that is used to calculate the rafters and beams (see Fig. 5). In our example, boards with a section of 25x100 mm are taken, their pitch is 350 mm. In the figure we see the inscription - "The bearing capacity of the crate is provided".

As a base for the corrugated board with which we want to cover this roof, in order to save money, you can use unedged inch boards. But you need to take only the so-called "second board" (see Fig. 17):

Figure 17

The price of such material is almost 2 times lower than that of edged material. There is just one very important note. Before laying the boards on the roof, it is imperative to clean off the bark from them. Beetle larvae (bark beetle) often live under it, which first eat the bark, and then proceed to the wood itself. Getting rid of them afterwards is quite difficult. Some say it's not possible at all.

STEP 7: Well, the truss system is ready. Now we cover the roof with corrugated board and sheathe the cornices with siding (see Fig. 18):

Figure 18

Thus, we made a non-insulated shed roof. It is clear that this design is only suitable for cold rooms. If we are going to heat the room, then the roof will need to be insulated. Let's see what additional work needs to be done for this.

We do the first five steps in the same way as described above. Then we expose the plugs for laying the insulation (see Fig. 19). We make them from inches (board 25 mm thick).

Figure 19

Now we put the heater. From below to the rafters must be hemmed vapor barrier film. It is not shown in the figure.

• Shed roof truss system in terms of assembly complexity, it is one of the simplest options, and also the most economical in terms of material consumption. Therefore, this design is most often used for the roof of utility rooms: garages, outbuildings, workshops and others. But, also this type of truss frame is also used for residential buildings.

  However, despite the ease of assembly, in the design of shed roofs, and even more so during their construction, it is imperative to comply with all the rules and requirements in accordance with SNiP. Why is it necessary to take seriously the assembly of such a simple truss system, and what should be considered in the process of work?

  What are the advantages of shed roof types

  As mentioned in the introduction, a single-pitched roof is superior to dual-pitched counterparts in terms of ease of construction. Such a roof can be cocked even alone, and in a shorter time. In addition, there are many other positive aspects due to which it is worth choosing a similar option.

  1

  Significantly lower consumption of materials:

  2 Easy installation. All the work can be done by one person, because there is no need to collect truss pairs, and even more so to carry out the lifting of heavy parts to the place of assembly of the truss frame. 3 Less weight of the structure. Due to the use of a small amount of materials, weight is reduced, which allows you to lay a lighter foundation for the entire structure. 4 Reduced wind load. Due to the lower silhouette, the shed roof is not so prone to windage, and this does not create wind resistance. 5 It is allowed to equip a residential attic (mansard). With the appropriate design of the building, it is quite possible to create an attic under a pitched roof. 6 The possibility of creating an exploitable roof.

  However, despite many advantages, similar designs they also have negative qualities that do not always allow the use of such types of roofs. The main negative properties of shed types of roof structures are as follows:

  • Undesirable use in regions with high rainfall during the winter. In other parts of the country, an accurate calculation is required, with a careful selection of the section of lumber.

  It is worth considering that such designs of truss systems are more appropriate to use in southern regions with low rainfall and constant winds. To the north, you should not build a roof with a slope angle of less than 45 degrees.

  • Higher requirements for waterproofing.
  • A shed roof does not always go well with the style and design of the house.

  Despite the shortcomings, shed roof options current version especially in low-rise private construction.

  Shed roof design. What to consider

  

  When planning the assembly of a shed roof, it is necessary to take into account and calculate many factors: the scheme of the truss system, the angle of inclination, loads, and select the appropriate materials. The result should be a drawing with complete information about the future roof.

  The classic scheme of a single-pitched truss system, these are beams laid across the structure with fastening, to, installed along bearing walls. This is the so-called shed roof with simple layered rafters. But this option is possible only for spans with a length of not more than 4500 mm. But, it is allowed to use shed roofs with a greater length.

  

  • With a span width of 5000-6000 mm, the layered rafters must be reinforced with struts, which are supported by a load-bearing wall with an additional Mauerlat.
  • If the width of the spans reaches 6000-7500 mm, you will need to assemble a more complex version - with an emphasis on the trussed truss. A headstock is added to the structure, supporting an additional beam on which the rafter rests. Naturally, the racks (headstock) are additionally reinforced with struts.

  In addition to choosing a truss system layout, at the project stage, you will need to plan the step between the beams, as well as their cross section. Such parameters also depend on the width of the span and the length of the rafters used between the bearing walls. General recommendations the following:

  

  • With a rafter length of up to 3000 mm, its cross section is selected within 80 × 100 or 90 × 160 mm. The step between the individual elements should be from 1100 to 2100 mm (depending on the section!).
  • If the rafter is 6500 mm long, in this case, a beam section of 120 × 220 mm is selected with a step between parts of 1100-1400 mm.

  But, in addition to choosing the appropriate section of the rafters, and the assembly scheme, a very important factor is the angle of inclination of the future roof.

  The choice of the angle of inclination of the slope

  

  The future functioning of the roof, as well as its strength, depends on the angle of inclination of the assembled slope. The optimal slope should ensure the removal of precipitation from the plane (especially snow), a low wind load, as well as stable fastening of the roof deck.

  The calculation of the angles of inclination of all roof structures must be carried out in strict accordance with SNiP 2.01.07-85 "Loads and effects". These building codes provide all the information on a particular region of the country.

  It is also worth considering the type of roofing material used, which is also recommended for use at different slope angles. For example, you can use the data from the table below.
  

  Do not forget that in regions with high rainfall in winter, the most optimal location of the slopes is 45 °.

  When choosing slope angles and roofing material, it should be taken into account that planes with slight slopes will have to be cleared of accumulated masses of snow, so it is best to choose a flooring that can withstand the weight of a person without subsequent deformations.

  Assembly of various options for roof truss systems

  Shed types of roof structures are most often used to cover utility buildings: garages, sheds and outbuildings. How is assembly work carried out?

  Shed garage roof

  Usually the width of the span at garages rarely exceeds 4000 mm, therefore, above this building, you can use the simplest circuit truss frame. Assembly is carried out in stages as follows:

  
  

  • Mauerlat is made from a bar with a section of at least 100 × 150 mm. To the outer edge, the part should not move closer than 50 mm. The element is fastened to the studs pre-embedded in the masonry. If the building is made of wood, then the upper crown of the walls performs the function of the Mauerlat.
  • Under the rafters, it is best to prepare a template of the appropriate length in advance. Moreover, it is desirable that initially the beam was a little more (by 50-100 mm from each edge) from the planned length. The required overhang of the cornices is formed after the installation of the rafters, cutting off the excess edges. Typically, roof overhangs are made in the range of 400-500 mm on each side.
  • Along the entire length of the Mauerlat, markings are made for a cut for rafters. Step between them according to the project. Wood is sampled to a depth not exceeding 1/3 of the timber thickness.

  

  • The manufactured rafters are installed in their places and connected to the Mauerlat in the chosen way (nails, staples, corners, etc.).
  • At the end of the installation, the rafters are trimmed to the required length, and closed with a stuffed wind board.
  • To form the roof overhangs in front and behind the garage, you can use two methods.

1. Mauerlat is taken out to the required length beyond the walls of the building.
2. Additional elements are attached to the extreme rafters - filly.

On a note

Accordingly, then the crate for the roofing is already being made!

Formation of the rafter system of the extension

Extensions to the house can have different parameters, and with a span width of less than 4000 mm, you can apply classical scheme with rafter support on two bearing points. However, with wider buildings (˃4000 mm) it will be necessary to install braces that abut against the wall of the building.

• A mauerlat made of 100 × 150 mm timber is laid on the outer wall of the extension. The fastening of the part is carried out in the chosen way (on studs, anchors), in a wooden structure the part is not mounted using the upper crown of the wall as a support for the rafters.
• In the opposite wall of the house, under the rafters, you need to prepare nests for the size of the rafters in the thickness of the wall (such grooves can be made even at the masonry stage).

• For struts, you can use a board 50 × 150 mm. They must be mounted at an angle of no more than 45 degrees to the supporting wall.
• The rafters are laid on the Mauerlat, leading the opposite ends into the prepared grooves. The beam is connected to the wall with mounting corners, and on the opposite side with nails or staples.
• Grooves are also prepared for the struts, having previously calculated the angle of inclination. The connection of elements with rafters can be done by driving staples or nails.

IN wooden houses fastening of the rafters to the wall is carried out by installing brackets (U-shaped for rafters) under the heels of the part from below.

After installation, the rafters are shortened, forming the overhangs of the cornices, and wind boards are stuffed. The next step is to mount the crate under the roofing.

When creating a truss system for a shed or utility block, the assembly scheme is chosen depending on the length of the future rafters, if the value exceeds 4000 mm, additional elements will need to be installed: struts, trusses and others.

Compliance with all the basic requirements will allow you to operate such a roof for 15-25 years, and with preventive inspections and restoration work much longer.

For small buildings, such as a barn or garage, a shed roof is often used. Simple in device, it is easily manufactured without the involvement of professional builders and looks very attractive. For the arrangement of residential buildings, such a solution is used less often: the power of tradition and the little experience of its design and construction for our places often work. It is time to evaluate the advantages of such a design.

Features: pros and cons

Shed roof is a rectangular absolutely flat shape, located at an angle with respect to the box of the building. The magnitude of its inclination may be different depending on the architectural design, climatic conditions and the surrounding landscape. When using high-quality materials, it lasts at least 20-30 years.

Such a roofing device is considered the most stable, including external natural influences, if the location of the structure is unmistakable in relation to the wind rose.

Snow falls on the surface in an even layer, which makes the load even and safe.

A sloping shed is better than a gable, although it does not allow for a comfortable attic space. But it’s easier with the ventilation system: aerators and a ventilated ridge are simply not needed.

The benefits also include:

• Small load on the supporting structures due to the relatively low weight.
• The lowest consumption of building materials compared to other types of roofs.
• Modest financial costs.
• A simple and quick way of erection, available for do-it-yourself.
• There are no restrictions in the choice of roofing materials and rafter system.
• Affordable planning and installation of drainage systems and chimneys.

Harmonious beautiful project requires compliance with many conditions, sometimes to the detriment of functional needs.

There are fewer disadvantages than advantages, but still, they are.

• To equip the living space of the attic, a significant width of the house and a high angle of inclination of the roof are required.
• A low bevel can cause poor thermal insulation.
• A reinforced gutter structure with a wider pipe diameter is required, since all the water flows in one direction. Recommended metal systems with fixing brackets at a distance of at least 40 cm.
• When the slope is less than 45 degrees, in order to reduce the load, in winter you will have to constantly clear the roof of snow.

Roof device

Like the structure of any roof, the qualitative composition of the elements of a shed depends on finish coat. The number of basic elements is small, but requires attention.

armored belt

Reduces the bursting load of the rafters and contributes to an even distribution of the weight of the entire structure. Required without fail for buildings made of aerated concrete, expanded clay concrete and brick walls if construction is carried out in an earthquake-prone region.

Mauerlat

It is located on the upper parts of the walls in the form of bars. It is connected to the armored belt or, in the case of a brick structure, it is fixed through anchors already hammered or walled up in the walls with a strong wire - at least 6 mm in diameter. The anchors themselves should be at a distance of 30 cm from the end of the wall. If the house is wooden, from a double mini-beam, then the role of the Mauerlat is performed by the upper trim

Gable

Rarely found in the construction of pitched roofs. Its presence is determined depending on the difference in height between the two load-bearing walls.

Rafter system

It serves as the basis for laying the roof, it is the main load. It is important to ensure that it is distributed evenly around the perimeter of the upper part of the entire building, and the pressure on the nodes does not exceed the permissible values. To create, wooden beams are used, the cross section of which depends on the area of ​​\u200b\u200bthe roof and the number of support elements.

supports

They are selected after calculating the weight of the structure and determining the finish coating. The quantity is determined by the angle of inclination and the length of the span.

crate

Necessary for laying and fixing roofing and increasing bearing capacity so that the frame can withstand its own weight and withstand additional loads: snow, the weight of a person during repair work.

For bituminous tiles, a continuous crate is performed. For these purposes, boards are used - edged or not edged, MDF panels can be used. The slope can protrude beyond the boundaries of the pediment, forming a visor for a veranda or terrace.

Insulation

Provides protection against moisture and freezing. It is laid from the side of the attic between the rafters and fixed on the crate.

insulation

It consists of rolled tile materials that are laid from the inside on the crate.

vapor barrier

Film coatings that are laid on top of the insulation and fixed with a construction stapler.

skate plank

Serves as a protection for the top rib of the roof, preventing moisture from entering and rotting the internal elements of the pie.

Fasteners

Rigel

View of a horizontal support for elements of load-bearing structures. The element distributes the load of the rafters between other beams.

Spacers

Supports that are placed in spans and increase the stability of the entire frame.

Struts

Kinds

Shed structures are popular in many countries and are used in the construction of both budget and trendy luxury housing. With a high slope of the roof, abandoning attic space, it is possible to optimize the layout. At low - there will be an increase in the volume of residential premises.

A flat roof often acts in tandem with other types, as an element of a multi-level system. This is a great addition for broken, semicircular and other varieties of roofs with different slopes.

Beautifully look two-level versions of "odnoskatok" with different angles of inclination, directed in opposite directions. Simple designs can decorate canopies that serve as part of a veranda or protruding attic.

According to the type of ventilation, 2 types are distinguished:

• ventilated - bevel from 5 to 20 degrees, holes are located in the cranked wall;
• non-ventilated roofs - the angle of inclination is from 3 to 6.

truss system

The creation of the project and the construction of the system depends on the scale of the construction and is determined by:

• climatic zone and wind rose;
• linear dimensions of the base - affects the number of rafter legs, the number of additional supports and the distance between them;
• angle of inclination - determines the presence of a pediment and the method of attachment to the supports;
• type of roofing material - dictates the choice of characteristics of the building material and the structure of the crate.

The pitch of the rafters also depends on their length and cross section:

• with a length of 3 m, the step is from 1100 to 2150 mm, the cross section is from 80 x 100 to 90 x 160 mm;
• at 6.5 m, distance - from 1100 to 1400 mm, cross section - at least 120 x 220 mm.

Often, for large buildings, a beam longer than 7–8 m is needed. To build it up, it is sewn together, and the joints are reinforced and fastened with planks or metal plates. The larger the elements of the rafters, there is less distance between them.

To ensure the rigidity of the structure, the following are provided:

• racks, crossbars and struts with a minimum section - 50 x 100 mm;
• beds and pads made of timber - 100 x 150 mm.

Classification of systems by width:

• Up to 4.5 meters. The simplest unsupported structures - the roof is fixed on a mauerlat of two logs or boards that are fixed to the walls.
• From 4.5 to 6 m. The structure is reinforced
  • lying down - at the height of the ceiling;
  • rafter leg - it serves as a support for the beam in the center of the base; the slope of the leg is determined by the width of the house and the height of the bed above the ceiling.

• From 6 to 9 m. There are two struts that are installed on both sides of the rafter leg.
• From 9 to 12 m. Another support is definitely needed, which can be part of a protruding inner wall or an additional cantilever-purlin structure, which is held by struts.
• More than 12 meters. The number of rafter legs increases significantly. An increase to the end of the roof overhangs leads to the build-up of beams along the edges with special elements - fillies. Fastening is done with overlays - at least 60 cm, which are fixed with bolts or nails, sometimes with mounting plates.

In addition, truss systems are distinguished by the type of supports.

slanted

The system of racks and struts rests on a Mauerlat beam, which is fixed on outer walls, and in some cases with inside. The distance between the rafters is from 600 to 1400 mm. The value depends on the weight of the roofing and the characteristics of the tree. Such simple designs available for roof slopes up to 26 degrees and spans up to 5 m. Most often used for outbuildings: sheds, workshops, garages.

For exploited roofs, that is, the angle of inclination of which tends to zero, the rafter legs abut:

• on the one hand - to a higher load-bearing wall;
• on the other - in the Mauerlat.

hanging rafters

They are used when it is impossible to install additional supports between the side posts. In this case, structures of any size are assembled on the ground or in a workshop, and ready-made trusses are delivered in stages to the construction site.

Possible materials:

• metal;
• reinforced concrete;
• tree (pine), section for rafters - 50 x 150 mm, for lathing - 50 x 50 mm.

sliding systems

Necessary for arranging the roof in buildings with significant shrinkage in the first period after construction. These include houses built from timber or logs - uneven subsidence up to 10%. For wooden structures the method of attaching the rafter legs is also very important.

The principles of the device are easy to learn:

• Installation of rafters is carried out on a ridge log.
• The legs can be connected end-to-end or overlapped (on nails, bolts and steel plates).

• The step and selection of the thickness of the wood for the rafters is determined by the weight of the roofing. With a top layer thickness of 50 mm, select edged board 200 mm wide.
• The attachment to the Mauerlat is special - slightly loose, without rigidity. This provides a kind of sliding, which avoids deformation of the roof during shrinkage and reduces the bursting load of the walls. As fasteners, special brackets made of steel, 2 mm thick, with a corner are used.

Tilt angle

The larger the angle, the higher the windage. Therefore, the roof slope should always be directed towards the most frequent winds. This reduces the load during a big storm. It is important to take into account the climatic zone in the calculations.

A slight slope can cause a lot of snow to accumulate. If it is not removed in time, wait for the formation of ice, the roof under its considerable weight will bend at best, and at worst, break through.

The natural descent of precipitation along the roof is an equally important reason when taking into account the surface and strength of covering materials. Rough types are best suited for dry regions, smooth - for places famous for heavy rains and snowy winters.

Optimal values for tiles:

• metal, ceramic and cement-sand - at least 6 degrees;
• bituminous - not less than 12.

Limit values ​​for sheet roofing:

• slate, corrugated board, ondulin - at least 6 degrees;
• copper, galvanized sheets (zinc-titanium) - from 17;
• asbestos cement slabs - from 27.

When choosing roofing materials, it is worth double-checking the information. Sometimes the declared slope values ​​for the coating specified by the manufacturer do not coincide with GOST. It is better to entrust the calculation itself to professionals, because there are many nuances, especially for large buildings.

After determining the slope, one of the load-bearing walls is brought to a level that will ensure the implementation of the project.

The necessary calculations to determine the length of the rafters, excluding overhangs, are made according to the rules of a right triangle.

To ensure the flow of water and protect the walls from getting wet, the roof is taken out by an average of 600 mm. For technical buildings, the minimum for the overhang is - by 20–25, for two-story residential cottages and mansions - up to 1200 mm.

The aesthetics of the entire building is also important. To determine your own preferences, before creating a project, you can use computer programs. This will allow you to see not only the entire roof, but also its harmonious combination with the house.

materials

The quality of building materials determines the strength and durability of the entire building, so roofing should be chosen carefully, taking into account the characteristics of both the building frame and the capabilities of the future truss system.

Wood

For the frame, wood of 1-3 grades is selected with a frequency of knots per meter - no more than 3, and their height should not exceed 3 cm. Cracks may be present, but shallow and of small length - not exceeding half the length of the board.

1. Bearing beams must have a thickness of 50 mm or more.
2. Board length:
   • from conifers - up to 650 mm;
   • from hardwood - up to 450 mm.
3. Additional elements - runs, Mauerlat, pillows - are made only from hardwood and treated with an antiseptic.

Roof

The modern range of roof coverings is very diverse, so it’s easy to choose suitable material by color, shape, required strength and price.

Ceramic tiles

The material can be of different types: flat tape, slot, one- or two-wave. It is well suited for roof slopes from 25 to 60 degrees for houses made of stone, brick or wood. At lower bevel values, it is necessary to strengthen ventilation and waterproofing, at large values, it will be necessary to additionally strengthen the nodes, install additional fasteners, because the tile is a very heavy material.

The weight of one fragment of 30 x 30 cm can vary from 2 to 4.5 kg, that is, 1 m2 can pull 50 kg. For comparison, a metal tile weighs 10 times less - 5 kg / m2. Therefore, the pitch of the rafters for ceramics requires a minimum and a wooden crate with small cells. But the tile has excellent sound insulation, beautiful colour and invoice. The strength of one element is small, but the service life of the entire roof exceeds the average life expectancy of a person and reaches 150 years.

metal tile

These are corrugated galvanized steel sheets, which have a polymer coating on the outside. Quantity protective layers, as well as the method of attaching elements to each other, varies depending on the manufacturer. There are both glossy and matte. Various sizes, thickness - from 0.4 mm, weight of 1 m2 - from 3 to 5 kg.

Assembly is carried out on the crate, fastening with nails or self-tapping screws, overlapping - in one wave. The recommended slope is from 15 degrees. If it does not exceed 20, then precipitation may drain too slowly, so the joints of the flooring are additionally sealed.

In general, metal roofing is quite strong and durable. The warranty period is from 5 to 15 years, but the wear of the polymer layer is not always taken into account. Of the shortcomings, only poor sound insulation and a large amount of waste.

Soft tiles

It is also called bituminous. The basis of the material is polyester, fiberglass and cellulose. They are applied to bituminous elements, and covered with a coloring matter on top. A special feature is adhesion, gluing elements under the influence of sunlight. Available in the form of rectangles or semicircular sheets. Service life is determined by manufacturers within 15–20 years without taking into account color fastness.

Parameters:

• length - 100 mm;
• width - from 300 mm;
• weight per 1 m2 - 8–12 kg.

A versatile material with good insulation, it is equally suitable for residential and commercial buildings. The recommended angle of inclination is from 12 degrees. The technology provides for a waterproofing substrate or lining layer. The role of such a carpet can be played by an old bituminous coating. Among the shortcomings are combustibility, instability to ultraviolet radiation and installation only in the warm season.

Decking

It is produced in the form of corrugated galvanized steel sheets of various sizes. The waves provide rigidity and strength to the coating, their height and shape depend on the specific model. There are trapezoidal, sinus-shaped or rounded.

Some manufacturers outside covered with a durable polymer film.

To ensure waterproofing, a glassine pad is used when laying. Fastening to the crate is carried out with self-tapping screws, the joints are treated with a bitumen composition. The recommended slope of the roof with corrugated board is from 10 degrees.

Like all metal roofs, the material has little sound insulation, so it is more often used for industrial facilities and sheds. The warranty period of operation is 15–20 years.

Ondulin

Universal covering material that can be used even for house cladding. It is based on cellulose, which is impregnated with refined bitumen with the addition of resins and pigments. The color is durable. Standard sizes sheet - 2000 x 950 mm, weight - 6.5 kg / m2, which is 4 times lighter than traditional slate.

The positive properties include:

• ease;
• strength;
• moisture resistance;
• excellent sound insulation;
• high resistance to temperature changes;
• resistance to chemical agents.

Although the minimum allowable slope level is 6 degrees, ondulin is not recommended for roofs with a slight bevel: it is not possible to hold snow for a long time. With higher values ​​and proper operation, the service life will be about half a century, the guarantee of water tightness is 15 years.

Slate

Corrugated sheets from composite material based on Portland cement and asbestos fiber. The shape of a corrugated sheet is always rectangular - 120 x 70 mm, weight - from 10 to 15 kg / m2. The level of the roof slope is from 12 to 60 degrees. The technology during installation provides for a lining layer of roofing felt or glassine.

The slate is overlapped to the crate with nails through soft hermetic gaskets.

The beam for the frame is selected:

• for a standard sheet - 50 x 50 mm, rafter step - from 500 to 550 mm;
• for reinforced - 75 x 75 mm, step length - from 750 to 800 mm.

Ruberoid

One of the popular budget options. Represents the roofing cardboard impregnated and covered with bitumen. To avoid sticking, a coarse powder is applied to the upper part.

The modern variety is euroroofing material, which consists of fiberglass or polyester impregnated with bitumen. There is a polymer layer on top. This elastic and waterproof material is often covered with small areas of the roof with a complex shape. The main disadvantage is rapid flammability, therefore, full installation can only be carried out at technical facilities.