Farms from a profile pipe: we calculate and make our own hands. Reliable profile pipe trusses Production of profile pipe trusses

For pitched roofs With large areas metal truss systems are needed. Buildings of this type include production workshops, pavilions, sheds for parking lots and other buildings for industrial and household purposes. Such rafters have the shape of a triangle or a semicircle and look like single or double slope structures with a small slope.

Metal trusses for the workshop

Features of the metal truss system

It is important to understand that the specific density of the metal is greater than that of wood, but the wood will be heavier due to the increase in the cross section of the profile. The section of the profile mainly depends on the load, and this is the wind power and the amount of snow in the area, multiplied by the area.

General concepts of a metal roof truss

Ferro alloy assembly

First of all, you need to understand the definition. A metal truss truss is a structure consisting of rafter legs, struts, crossbars, struts and racks. All these elements are connected (welded) to each other and are in one common plane.

Metal truss device

But to be more precise, such a concept implies a hanging structure of the above elements with an emphasis on racks. The options may differ from each other in the number of jumpers, the slope of the rafter legs and the total length of the assembly.

The choice of trusses primarily depends on the size of the area, roofing material and atmospheric mechanical loads (snow, wind).

Depending on the outlines, farms are divided into four types:

• lean-to;
• with parallel belt
• polygonal design;
• triangular.

The main forms of metal structures

What profile is used for metal trusses

Items for truss systems most often they are made from a paired profile (two semi-farms), where the nodal connections are reinforced with scarves (struts). The upper belt of the truss is made of two non-equilateral corners, which after installation look like Taurus. Between themselves, they are fastened by welding or bolted connection.

With an increased load on the rafter system, paired channels or I-beams are used within the panels. Racks, braces and other jumpers are made in the form of a cruciform T-shaped structure. But in the case when all the nodes on the farm are connected by welding, it is better to use the brand, since this is a solid (more powerful) profile.

Pipe profiles different section

In private construction, a profiled pipe is usually used - hollow materials are much lighter than a brand, an I-beam and a channel.

Another advantage of such a metal structure is its mobility, that is, the farm is very easy to assemble at the construction site. In addition, any design can be made from pipes (round or profiled).

Pipe profiles that are used for such trusses can be either bent (seam) or hot rolled. The wall thickness of more durable hot-rolled pipes is from 1.5 to 5 mm, they are made with a rectangular or square section. The bending power of the pipe is not less than that of the brand, but the mass of the latter is greater.

What to consider for truss systems with different slopes

Regardless of what kind of roof is being built (single-pitched, gable or bent), trusses are distinguished by the angle of their slope. In a general sense, such structures are divided into three categories: with a slope of 22-30ᵒ, 15-22ᵒ and 6-15ᵒ.

Requirements for trusses with a slope of 22-30ᵒ

Shed truss canopy

In cases where the building design provides for a slope slope of 22-30ᵒ, slate, eternite (composite slate) or iron (tin seam) are usually used as roofing material. The height of the triangular truss along the ridge beam should be equated to 1/5 of the span length (with a leg length of 10 m, the height of the ridge will be 10/5 = 2 m or 200 cm minimum).

This design will turn out to be the lightest and atmospheric precipitation will drain faster from it.

For large spans from 14 to 20 m, it is preferable to choose a design with downward braces - it best tolerates snow and wind loads, therefore, it has less weight. The panel in the upper belt here is about 1.75-2.5 m long and in each pair their number should be even. This means that the number of spans at specified dimensions equals 8 (14/1.75=8; 20/2.5=8).

Roof with a slope of 30 degrees

For industrial-type buildings (production workshops, pavilions, and so on), the span reaches 25-30 m, and in this case it is advisable to use Polonso trusses. These are also paired structures that are connected by a puff. Here it is possible to avoid the installation of long braces in the central panels, this significantly reduces total weight construction, and as a result - the amount of material required.

• The upper belt in this case is divided into 12 or 16 compartments of 2-1.85 m each (25/12 = 2.08 m; 30/16 = 1.85 m).
• The lower belt is raised to increase the angle. The load in the belts is reduced, and the support nodes are the simplest. Suspended ceilings for such structures are not used.

Truss construction with slope slope 6-22ᵒ

• If the metal roof truss has a slope of 15-22ᵒ along the slope, then its height along the ridge beam should be equal to 1/7 of the span length. To increase the height by 0.16-0.23 parts of the span length, the lower belt is made of a broken type. This method reduces the weight of a truss with a conventional triangular structure by up to 30%, but the span length here is allowed no more than 20 m. In cases where the span increases more than 20 m, the Polonso design is used.
• If the roof is almost flat and has a slope of no more than 6-15ᵒ, it is best to use trapezoid trusses. Most best option, this is when the skate is at a height of 1/7 or 1/9 of the sum of the total span length. For example, with a leg length of 10 m, the height of the ridge is 10/7 = 1.42 m or 10/9 = 1.11 m.
• If the ceiling suspension is not provided for the rafter system, the braces are installed in the form of a triangular lattice. The number of sections or panels is calculated according to the same principle as for conventional triangular structures.

It is important that attic walls and truss supports are of sufficient height. Otherwise, the roof is designed with a fracture at the supports - this allows you to create the right space.

For suspended panels, their dimensions must correspond to the length of the lower and upper elements. That is, their length is a multiple of 2 along the length of the rafters, but not more than 1.5-2 m. It should be noted that Polonso trusses are most suitable for ceilings of complex shape.

Important nuances of the calculation and installation of metal trusses

Assembly of a paired metal truss (red line indicates the welding seam)

Features of the installation of metal rafters

In cases where the length of the trusses exceeds 10-12 m, the metal roof is calculated as a paired system. That is, rafter legs together with the jumpers, they should be made up of two parts, since it is difficult to transport them as a whole - this is inconvenient, and economically expensive.

It is much easier to divide the truss along the rafter legs into two fragments and later connect them with puffs and welding than to mount such a structure at the construction site. But here it is very important to take into account that the components are not divided into left and right - they must be the same. Otherwise, it threatens confusion at the assembly site.

The connections of the two parts are carried out with the help of pads, which are fixed with bolts and welding at the seams at the joints.

Each option is different from each other, but the more bolted connections, the stronger the knots will be - puffs will help fix the welds of the truss metal structure.

The dependence of the length of the rafters on the slope of the slope

For the correct calculation of a metal roof at home, it is necessary to rely on SNiP P-23-81 and SNiP 2.01.07-85:

1. First of all, choose the appropriate scheme of the truss system, based on the slopes of the slope, the type of roofing material and the purpose of the structure.
2. If typical requirements do not provide for certain contours, then design the structure according to the principle of saving materials.
3. Determine the height of the upper corner by the strength of the coating (the most obtuse upper corner is made for metal tiles, corrugated board or seam roofs).
4. Size panels (sections) according to the slope, as suggested in the three subheadings with different truss angles in this publication.
5. To avoid long and complicated calculations, take as a basis any standard project that fits the size of the building.

Farms from profile pipe in the roof device

Do-it-yourself truss manufacturing and installation

Most often, for the manufacture of metal trusses, do-it-yourself profile pipes are chosen, which are welded together.

• For canopies up to 4 m wide, a pipe with a cross section of 40 × 20 × 2 mm is suitable.
• For a roof with a width of up to 5.5, pipes 40 × 40 × 2 mm are needed.
• With a building width of more than 5.5 m, profiles 40 × 40 × 3 mm, 60 × 30 × 2 mm are recommended.

Work begins at the bottom, and then the workpieces are lifted and welded to the racks. Lifting and holding heavy structures in position will require machinery.

Do-it-yourself canopy roof assembly

The procedure is as follows:

1. Lay longitudinal pipes on the ground and weld them to the support posts.
2. Connect the upper and lower belt with braces and jumpers.
3. Raise the metal structure and weld it to the longitudinal pipes of the uprights
4. After installing all the trusses, connect them with longitudinal jumpers along the slope. The distance should be half a meter. These jumpers will later serve as a support for the installation of roofing sheets. All irregularities must be carefully cleaned, otherwise roofing does not lie flat and without gaps.
5. Clean the surface of the structure, grind the metal, degrease with special compounds, apply a primer layer and paint.

Video: Arched pipe roof

In conclusion, attention should be paid to accuracy - the slightest oversight in the calculations of a metal roof will lead to a skew, which means an error in the entire roof structure. If you do not rely on your mathematical abilities, seek help from specialists.

Farm structure options
Design features
How to calculate steel pipe box
Arched truss - calculation example
Veneer veneer - material requirements
Helpful tips on how to cook

Using profiled pipes for building trusses, it is easy to create a structure that can prevent significant efforts.

Such structures are simple and suitable for building construction, chimney chimney construction, under-roof fixing supports and canopies. The shapes and general sizes of the clusters depend on the purpose of the structure and its use, whether it be a household or an industrial plant.

In this article, we will discuss how to make a correct and accurate slope calculation from a metal profile pipe. If this is not done, it is unlikely that the model will support the required load.

Profile pipe metal structures are typical for large scale work, but are much more economical and simpler than markets built from solid materials.

Profile pipes are obtained from round pipes with hot or cold rolling technology. As a result, there are pipes that look like cross-sections of various geometric shapes, such as rectangle, square, polydr, oval, semi-oval, etc. For stem construction, square pipes are more suitable because they are stronger due to having two identical solid ribs.

The truss is a metal structure characterized by the presence of upper and lower levels, which are connected in the form of a grid.

In addition, compounds cannot be any, and their number is calculated in accordance with this formula.

The lattice solution includes:

• The stand is installed vertically;
• Frames (washers) located at an angle to the workplaces;
• (auxiliary brakes).

Farms are generally designed to connect ranges for different economic purposes.

Due to the presence of elements such as carriers, they carry significant loads without deformation, even if they cover large lengths.

As a rule, the farm is located on the ground or in special production facilities. All frame elements are interconnected by welding or riveting. For the construction of a canopy, a large building project, or other building on a rooftop, ready-to-assemble earth on a truss is mounted and placed on suitable design, which adheres to all sizes.

The connection of the ranges is carried out by various metalworking mills, for example:

• unilateral;
• gable;
• directly;
• arched.

Trusses, similar to a triangle and made of similar pipes, serve as rafters, as well as elements of classic bearings.

Arch trusses are very popular due to their aesthetics as well as their resistance to heavy loads. In this case, vaulted trusses are assembled according to more complex data, so the forces are distributed evenly across all elements of the truss.

Design features

Farm construction for various construction projects depends on expected workload and economic goal.

Depending on the number of lanes:

• Support structures, the elements of which consist of one level;
• which differ in the presence of upper and lower bands.

Structural structures provide for the use of graves with different contours:

• with a parallel belt (most basic version where the same elements are used);
• one-sided triangular (for all support nodes characterized by increased strength, so the structure can withstand significant loads);
• Polygonal (transmits the power of a solid frame, but is difficult to install);
• trapezoidal (have similar data with polygonal, but not so complex in the device);
• triangular chain (used to install steep tiles from a profile pipe, but they have a large source of costs);
• Segmented (suitable for structures where the installation of a transparent roof is difficult, since it is necessary to produce elements with the correct geometry for uniform distribution loads).

Depending on the slope, classic trusses are classified as follows:

1. It is 22 to 30 degrees when the ratio between height and length is 1:5.

   Suitable for the simple construction of conventional profiled pipe ceilings.

To cover the small to medium size range, triangular types of veneer welded from small diameter tubing are used because they are strong and light enough.

If the span exceeds 14 meters, the design provides a downward support attached to the top flange and a panel size of 150-250 cm for a two-zone structure with an integer number of plates.

If the range is more than 20 meters, in order to avoid bending the carrier, it is necessary to provide for the installation of elements of the substructure of the structure, attaching it to the supporting columns.

1. Particular attention should be paid to the Polonso farm, which consists of two triangular structures stacked on top of each other in their own way.

   In this design, there is no need to assemble long supports in the middle part, which allows to reduce the overall weight of the structure.

2. It is 15 to 22 degrees, height to length ratio 1:7. Allows farmers to attach extended lengths up to 20 meters. If you want to increase the height of the farm, you will need to create a lower level.
3. It's less than 15 degrees. Such a frame should contain trapezoidal elements.

   Such a truss has a short pillar, which causes the carrier to have a buckling. For angles of 6-10 degrees, facades should have an asymmetrical design. Determine the height of the truss by dividing the span length by 7, 8, or 9, depending on the characteristics of the project.

How to calculate steel pipe box

The calculation of any metal structure is an important and decisive phase, regardless of the design of which it is planned.

The calculation of the scissors system from a profile pipe is reduced to the following points:

1. Determine the size of the design range to be closed and the configuration of the roof with the effective angle of inclination (skate).
2. Choice optimal contour belts on the farm, taking into account the nature of the structure, the shape and size of the roof, the inclination of the slope, the structural load.
3. Determine the optimal structure height at the center of the range (H) based on the following formula (where L is the length of the rack).

   For parallel, polygonal and trapezoidal strips: H = 1/8 × L. In this case, the height of the upper chord should correspond to 1/8 × L or 1/12 × L. For a triangular truss: H = 1/4 × LH = 1 / 5×L.

4. Specify the conditions for collecting a design depending on its size. If the dimensions of the metal are impressive, it is best to boil it there at the construction site, and only after that with the construction elevator to be fixed in the city, and if the measures are small, the farm is better to cook in the factory room, then deliver it for transportation to the installation site .

   Although the other option is more expensive, it is more reliable, as it is very difficult to work in an unprepared place.

5. Calculation of the size of the panels depending on the structural loads working on the roof during work.
6. Specifies the angle of the lattice mounting beams, which can be in the range of 35-50 degrees, although it is desirable to install them at an angle of 45 degrees.
7. The next step is to determine the distance between the fixing nodes, although the distance is usually equal to the width of the panel.

   In the range of 36 meters or more, it is necessary to calculate the size of the construction elevator - the reverse adjusted curve that it plans during operation.

8. Taking into account all measurements and calculations, a technical drawing is taken with all required dimensions, according to which a metal structure is made from a metal tube.

To avoid significant discrepancies in the calculations, it is better to use a construction calculator.

Based on a specific program, you can calculate any metal structure, including roof shears from a profile pipe.

Arched truss - calculation example

Proper calculations must be made when building a bow-shaped truss for normal crochet.

In this case, which corresponds to the size range of 6 meters, in the gaps between the 1.05 meter high arches, the 1.5 meter construction corresponding to the vaulted truss shows how all the necessary calculations are performed. This plan is designed not only for its strength, but also for aesthetics. the range of lengths of the lower level corresponds to an arc of 1.3 m (F), and the radius of the circle in the lower band is 4.1 m (r).

The angle between the radii is 105.9776º (a).

How to weld pipes from a profile pipe

The length of the profile tube (m) for the location of the lower belt is calculated by the formula:

mh = Pi × R × a / 180, where:

mh is the length of the lower belt profile;

Pi is a constant value (3.14);

R is the radius of the facade of the facade;

a is the angle between the radii;

after all, this should be avoided:

mh = 3.14 × 4.1 × 106/180 = 7.58 m.

Structural hubs are located on the lower sections of the belt at a distance of 55.1 cm.

To facilitate assembly, it is desirable to go around this distance up to 55 cm, while increasing the installation degree of the node is not recommended. Removal between extreme points should be calculated separately.

With a range not exceeding 6 meters, it is allowed not to perform complex calculations and not to use welding.

It is enough to use a single or double beam, bending the structural element with the desired radius.

However, you should generally choose the thickness of the metal elements so that the bow can support all loads.

Veneer veneer - material requirements

The production of working models of trusses, especially large ones, requires certain pipe characteristics.

Therefore, profile tubes are selected:

• based on SNiP 07-85 (influence of snow load on all structural elements);
• based on SNiP R-23-81 (according to the technology of working with profiled steel pipes);
• in accordance with GOST 30245 (coherence of pipe diameter to wall thickness).

All basic data is stored in specific documents that allow you to view information about the availability of pipe profile types and select materials suitable for specific projects.

As a rule, only high-quality metal products are used for the production of agricultural holdings. For example, in solid farms only stainless steel more weather resistant. In this regard, such designs do not require additional protection against corrosion.

After familiarizing yourself with the network mesh technology, it is easy to install a light and strong roof frame or translucent material.

It is advisable to take into account some shades:

• If a strong and reliable construction is required, a square-shaped metal tube is preferred.
• For greater rigidity, the main elements of the carrier are connected using metal corners and levers.
• When mounting media parts in the upper range, it is desirable to use I-shaped wires at different angles that connect the parts on the narrower side.
• Equivalent angles (I-beams) are used to provide details of the bottom band.
• By overlapping the main parts of the metal structure of great length, the upper metal plates are used.

Well, the most important thing is to decide how to weld a box from a profile pipe.

This is especially true if there is a need to do this on a construction site. Such designs are made by welding, and since welding requirements are prescribed for the quality of welding, this cannot be done without a good welding machine and equipment.

The bracket stands are fixed at a right angle, and the brackets at a 45 degree angle. To begin with, it is better to work in the assembly of the main and auxiliary elements of the carrier, cutting the profile tube into cuts in accordance with the dimensions indicated on the working drawings. After that, the structures on the ground begin to weld and constantly control the geometric dimensions.

During the welding process, it is necessary to control the quality of each weld. This is very important because the farm is at a height and has a certain risk to others.

Profile pipe farm

metal markets These are rod systems consisting of belts and gratings. Due to the reinforcement, such structures do not deform even when significant loads are detected.

Depending on the complexity of the form, they can be produced directly at the construction site or in specialized production. A popular material for making cutters is square or rectangular. cross section.

Materials for profile pipes

Various metals and alloys are used to make shaped tubes that can be used in veneer construction:

• in general- carbon steel of ordinary quality;
• for responsible structures- high-quality carbon, low-alloyed, less common - resistant to corrosion;
• work in an aggressive environment- carbon steel coated with a protective layer of zinc (galvanized);
• when it is necessary to create light structures- light and powerful alloys based on aluminum.

Pipes of small cross sections up to 6 m long are for sale, large pipes up to 12 m.

The wall thickness and cross-sectional dimension are selected according to the planned loads:

• for range up to 4.5 m- 40 x 20 mm with a wall thickness of 2 mm;
• 4.5-5.5 m - 40 x 40 mm with a wall thickness of 2 mm;
• over 5.5 m- 40x40x3 mm or 60x30 with a wall of 2-3 mm.

Types of construction of graves from a profile pipe

The structure of the standing positions includes the upper and lower bands and the network that lies between them.

Lattice components:

• pillar- which is located perpendicular to the axis;
• spacer- installed on a slope on the axis;
• the seam- auxiliary circuits.

Agricultural belts can have different contours:

• triangular envelope.

  For a triangular one-sided profile pipe network, it is characterized by a combination of the ability to transmit high loads with a low material capacity.

• Tripartite Sponsor.

  Such structures can be installed on roofs with a high slope of the ridges. Cons: the complexity of the supporting nodes of the device, high material consumption.

  The constructive version is a triangular tip made of a profile pipe.

• segmented.

  It is often used for roof construction with transparent honeycomb or monolithic polycarbonate.

• polygonal. The complexity of the installation varies. The advantage is the ability to withstand heavy loads from heavy flooring and heavy snow cover. An additional advantage is the economical use of the profile.
• With parallel stripes.

  This is the simplest and most economical mounting option and is used with equal sized poles and poles. Parallel belt trusses are easy to assemble due to a single design, a large number of parts of the same size and the fewest connections. Suitable for soft and translucent roofs.

• trapezoidal.

  Similar to polygonal, but has a simplified installation scheme.

• Shape with parallel top and bottom stripes. Arched arches made of profiled pipes are in demand in the construction of furniture for cars, greenhouses, gazebos.

Lattice model options:

• triangular shape. Usually such a scheme is used in frames with parallel stripes, less often in knitted or trapezoidal forms.
• Type Dextrous.

  They are characterized by high intensity and complexity of execution. Variante - sprigelnaya (with additional racks), translucent.

• Individual solutions.

Farm selection depending on the angle of inclination

The choice of design possibilities depends to a large extent on the inclination of the ramp:

• 22-30°. Triangular veneers are usually used to form slopes with an important slope. Their height is the length of the range divided by 5.
• 15-22°.

  The height is assumed to be the span length divided by 7. To increase the height of the carrier structure, use the options with the bottom bar broken.

• Up to 15°. Typically a trapezoidal frame is used with a triangular mesh configuration. The height of the blocks in these cases is determined by dividing the length of the range by a number between 7 and 9.

Calculation of graves from steel profile pipes

overhanging farm- a critical structural element, before doing this, be sure to perform calculations and compile the project.

The implementation of settlements should be entrusted to an expert, since the correct design of a profile pipe truss in several respects determines the functionality of not only the roof, but the entire structure. If you have certain knowledge and the creation of small objects, you can use special computer programs "Autocad", 3D MAX, Arcon.

Design phases

• Determine the size of the structure, the shape of the roof, the slope of the skates.

  At the same time, we will consider the planned roofing materials, snow and wind loads specific to the region, and the type of soil. It also takes into account the likely special loads that a truss made from a pipe profile may experience - storms, hurricanes, earthquakes.

• Select according to the specified parameters. constructive type farms.
• After approximating the dimensions and design, the choice of production is determined - at the factory, assembly of empty seats on site, or the entire cycle of purchase and assembly on the site.

Useful tips for creating your own profiled hose edges

• An additional grid is used to simplify the structures used to build a roof with minimum slope ramps.
• To reduce the weight of the skeleton arranged to organize ramps with a slope range of 15-22°, the bottom strip is made of a polyline.
• With a run length of 20 m, Polonso frames are used, consisting of two triangular structures that connect the screed.

  This setting avoids a large installation.

• The distance between hinged structures should generally not exceed 1.75 m.
• When choosing a hose for difficult conditions operation, it is necessary to take into account the class of steel from which they are made.

  Calculation and production of graves from a profile pipe

  For regions with a cold climate, pipe products are used from low-alloy steels, which demonstrate high resistance to low temperatures. In case of a high risk of corrosion, galvanized products should be used.

The main stages of creating and installing graves from profile pipes

Procurement, installation and installation activities must be carried out by experts with the appropriate knowledge, skills and tools.

It is important to determine which work can be done below and which work will require special construction equipment after the main structure has been raised to the installation site.

The procedure for installing veneers from profile pipes when crocheting and others frame structures includes the following measures:

• Cleaning, leveling and marking the site.
• Installation of metal vertical beams with penetration and concrete.
• Pressing and retrofitting cross ties.
• Installation and welding of blanks of graves from profile pipes in accordance with a pre-planned scheme.
• Lift the assembled façade units to the installation site.
• Welding on built-in lintels with holes designed for mounting roofing material.
• Cleaning the seams, especially on the top edges of the frame.
• Removable elements of metal structures. When using a profile without a galvanized coating, its surface is coated and painted, which can significantly extend the period of operation.

See also:

A variety of metal pipe trusses
Farm drawing from steel profile
How to calculate an arched profile truss
Farm Profile Calculation Guidelines
Practical tips for calculating profiled pipe trusses

At the heart of the overlap of any outbuilding, whether it is a residential building, a hangar, industrial shop or a whole stadium, they lay a special frame - a farm.

The most popular recently began to use farms from a profile pipe. We will talk about the types of trusses from profile pipes, as well as how to make calculations for the manufacture of a particular design, later in the material.

There are a lot of varieties of metal trusses from a profile pipe, and in some cases they even become the basis for chimneys.

But in order for the whole structure to be strong and reliable, it is necessary to correctly execute the drawing according to which the frame will be made.

A variety of metal pipe trusses

As a rule, a metal profile is used to make trusses from a profile pipe. Its shape is oval, round, square, but most often a rectangular profile pipe is used.

According to the structure of the structure from the profile pipe, they are divided into two types: the structural elements of the frame can be fixed in one plane; the truss can be made up of lower and upper chords.

In addition, the classification of rectangular pipe trusses is based on factors such as the level of load on the profile, the angle of inclination of the elements, the overall slope of the structure, the length of individual spans, and the nature of the location of the floors.

Based on these parameters, all typical profile pipe trusses consist of the following groups:

1. Farms, the slope angle of which reaches about 22-30º. For such a design to be stable, its height should be equal to 1/5 of the length of the product or be somewhat less.

   As a rule, this norm is taken as the basis for calculating the required height of the structure, that is, the given length of the product is simply divided by 5. This type of truss is preferable if the structure should be as light as possible.

   If the estimated length of the building is more than 14 meters, then the position of the braces in the truss structure from the profile pipe for the canopy will be vertical. On the upper tier, pieces of a profile 150-250 cm long are fixed. As a result, the entire frame will consist of two belts, with the number of panels a multiple of two. Pay attention to the fact that if the truss is very long - more than 20 meters, you will need additional support posts that will support the truss system and allow you to redistribute the load throughout the structure.

   Often, for the construction of a frame for floors, the Polonso farm scheme is used. It is a triangular structure, the connection in which has the shape of a puff. During its construction, the braces are not very long, which greatly facilitates the mass of the entire farm. Due to this quality, Polonso profile pipe trusses are used quite often.

2. The slope of the roof on the farm reaches 15-22º. This type structures is preferred for buildings whose length does not exceed 20 meters.

   In height, such a structure should not exceed 1/7 of the length of the building. If it is necessary to increase the height of the truss, then its lower belt should consist of broken segments.

3. Frames with a total slope of no more than 15º. As a rule, if we are talking about this kind of farm, then it is made in the form of a trapezoid. Based on the purpose of the building, as well as the angle of laying the roof, the owner determines the height of the structure independently. You should start from indicators between 1/7 and 1/12 of the length of the building.

   A frame for a roof in the form of a trapezoid is made using metal panels, the length of which should be in the range of 1.5-2.5 meters. If the drawing of a truss from a profile pipe does not provide for a false ceiling, then a triangular lattice can be used instead of braces.

According to the shape of the truss from steel profile pipes can be divided into:

• straight;
• arched;
• single-sided and double-sided.

The most popular and frequently used type of steel profile trusses are arched.

Their design is quite durable and efficient, in addition, such a farm can be covered with polycarbonate sheets. However, in order to achieve the most even distribution of the load on the profile of the arched truss, calculations should be carefully carried out.

For the construction of arch-type trusses, both single profile pipes and pre-welded together can be used.

Steel profile truss drawing

Drawing up a drawing and calculation of a truss from a profile pipe is carried out in compliance with the following methodology:

1. First of all, you should deal with the calculations of the planned or actual length of the room, for example, a garage, hangar, barn or summer shed. The received data will be taken into account when calculating the height of the farm from the profile.

   But the length of the steel frame may vary depending on the angle of the roof.

2. The next step is to determine what shape the profile will be used.

   The choice largely depends on the functional purpose of the hangar, the angle of the roof slope, and the type of roofing material.

3. After carrying out all the measurements, it remains to be seen whether it will be possible to transport the truss to the installation site if it is assembled at the construction site.
4. You will also have to take care of equipping the mechanism for the construction lifting of the roof, if the length of the object reaches values ​​in the range of 12-36 meters.
5. Next, the parameters of the panels are calculated based on the level of expected loads to which the building will be subjected permanently or periodically.

   For a triangular profile truss, the slope will be 45º.

6. At the final stage, a step is laid between the nodes and a drawing of the future truss is made from a profile pipe, based on the data obtained.

Note that in order to obtain the most correct calculations when preparing drawings for an arched truss, it is better to use an engineering calculator.

In addition, special computer programs and algorithms have now been developed to help designers, so there is no need to calculate manually.

How to calculate an arched profile truss

In order to analyze the methodology for calculating an arched truss from a profile pipe, we will give an example with specific numbers.

Separate sections of the farm will be placed at a distance of 105 cm, with the maximum load falling on the nodal points.

In this case, the height of the arch will not be more than 3 meters. Moreover, it is desirable to make an arch with a height of 1.5 m, which will make it more durable, safer and quite attractive in appearance. The length of the truss (L) will be 6 meters, and the lower chord boom (f) will be 1.3 meters. In the lower tier, the radius of the circle (r) will be equal to 4.1 meters, and the angle between the radii will be α=105.9776º.

To calculate the length of the profile for the lower tier, we use the formula:

mn=π×Rα/180, where

mn - profile length for the lower tier;

R is the radius of the circle;

π is a constant value.

Thus, we get the following calculation:

mn \u003d 3.14 × 4.1 × 106 / 180 \u003d 7.58 meters.

In this case, in the lower belt, the step between the corner points will be 55.1 cm, but for the extreme segments on both sides in the belt, the step must be determined independently. You can use a rounded value of 55 cm, however, in any case, it is undesirable to increase the step length.

If a profile truss is required for a small-sized construction, then you can limit yourself to the number of spans of 8-16 pieces.

If we take a smaller number of spans, then the panels will reach 95.1 cm in length with a step between the belts within 87-90 cm. With the largest number of segments, the step will be 40-45 cm.

Farm Profile Calculation Guidelines

For the correct choice of profile, especially if it will be used in large structures, one should start from the indicators of SNiP:

• 07-85 - information about the nature of the relationship between the weight of the structural elements of the structure and the impact of snow loads;
• P-23-81 - the sequence of work with steel profile pipes.

Guided by these documents, you can decide which type of truss to choose for a particular type of building, which angle to lay the roof, and also choose the right section and dimensions of the profile pipe for the support pillars.

In particular, the regularity and intensity of precipitation in winter can greatly influence the choice of a profile for a farm. See also: "How to weld a farm from a profile pipe - instructions and recommendations."

For clarity, let's consider a real example of calculations for a single-pitched truss from a profile pipe. A canopy with dimensions of 4.7 × 9 meters will be built. In the front part, it should rest on support pillars, and the back part will be fixed on a residential building. The building will be located in Krasnodar Territory, where the level snow load V winter time is 84 kg/m2.

The overall slope of the structure will be only 8 degrees.

Each of the racks will have a height of 2.2 meters and weigh about 150 kg. In this case, the load on them will reach 1100 kg. In this case, neither round nor oval profile pipes are acceptable. You need to use square 45 mm profiled products with a wall thickness of 4 mm.

Alternatively, the design of the truss can be slightly modified by adding 2 parallel belts with an oblique lattice between them, in which case profiles with a wall of 3 mm and a cross section of 25 mm can be dispensed with. The truss height of 40 cm involves the use of profiled pipes with a cross section of 35 mm and walls of 4 mm.

The ratio of the profile section and wall thickness depending on the load can be found in GOST 30245.

To ensure that the profiles in the arched truss are protected from impact environment and were reliable, they must be made of quality material, preferably alloy steel with sufficient carbon inclusion.

When developing a metal truss project, you should pay attention to a number of nuances:

• to lighten the overall weight of the metal truss, it is possible to install auxiliary gratings during the construction of the hangar - an option is acceptable if the slope of the roof is small enough;
• the broken shape of the lower belt will help to significantly reduce the weight of the structure with an average slope angle;
• Roof strength can be ensured if trusses are placed in increments of no more than 175 cm.

Assembly and welding of profiled trusses metal pipes must be carried out in accordance with the following rules:

1. For a strong connection of all structural parts of the structure, twin corners and tacks are used.
2. In the lower chord, equilateral corners are used for welding elements.
3. For the upper chord of the truss, I-beams are used for welding.

   Farms from a profile pipe: we calculate and make our own hands

   They are fixed end-to-end on the smallest sides, having different lengths.

4. In order for the load to be evenly distributed throughout the structure, paired channels and lining plates are used.

   As a rule, this technique is used when you need to make the canopy longer.

5. All welds must be carefully rechecked upon completion of work. After that, you can clean up.
6. If necessary, then at the end the farm is painted with an anti-corrosion compound.

   If the profile is made of alloy steel, then it does not need to be painted.

Thus, for numerous buildings of economic or industrial use, trusses are often made from profiled pipes. Due to the significant complexity and laboriousness of the calculation process, it is better to entrust the design and creation of a drawing to professionals.

Benefits of using metal rafters
Classification of graves from a profile pipe
How to calculate how to slope
Calculation of a metal bar
Calculation examples
Recommendations for the selection of pipes and the creation of metal structures

Graffs from a profile pipe are often used in various construction industries.

Such farms are structurally composed of metal structures, which consist of individual rods and are shaped like a grid. Since the construction of solid beams, trusses are cheaper and labor intensive. Both welding process and rivets can be used to connect pipe hoses.

Markets for metal profiles are suitable for creating an extension, regardless of their length, but it is possible, the design must be calculated with assembly accuracy.

If the calculation of the metal substrate was correct and all the work on the assembly of the metalwork was done correctly, the finished truss should be lifted and installed on the belt only.

Benefits of using metal rafters

Profile tube cuts have many benefits, including:

• Mass of light design;
• Long service life;
• Excellent power characteristics;
• Ability to create complex configuration structures;
• Permissible cost of metal elements.

Classification of graves from a profile pipe

All metal structures on a truss share a few common parameters that allow the truss to be divided into views.

These options include:

1. number of belts. Metal markets can only have one band and then the whole structure lies in one plane or two bands. In the latter case, the farm will be called hanging.

   The structure of the hanging truss includes two strips - upper and lower.

2. Form. There is a vaulted truss, a straight line, one-way and two-way.
3. Circuit.
4. Like a slope.

Depending on the contours, the following types of metal structures are distinguished:

1. Parallel belt trusses.

   Such structures are most often used as support for roofing roofing. roofing materials. A parallel belt truss is created from the same parts with the same dimensions.

2. fruit farms. Single ramp models are cheap because they have few materials.

   The finished structure is strong enough to ensure the rigidity of the assemblies.

3. polygon farm. These structures have a very good load capacity, but they have to pay for it - polygonal metal structures are very inconvenient to install.
4. three markets.

   As a rule, markets with a triangular contour are used to install roofs that are located at a large slope. Among the shortcomings of such farms, one should note the significant amounts of additional costs associated with the mass of waste in the production process.

How to calculate how to slope

Depending on the angle of the truss, trusses are divided into three categories:

1. 22-30 degrees.

   In this case, the ratio between the length and height of the final structure is 5:1. Trusses with this gradient, which are distinguished by their lighter weight, are excellent for placing short ranges in private construction. As a rule, trusses with such a slope have a triangular contour.

2. 15-22 degrees. In a design of this size, the slope of the length is seven times the height. Such holdings should not have a length of more than 20 m.

   If it is necessary to increase the height of the completed structure, the bottom strap looks broken.

3. 15 or less. The best option in this case would be metal rafters from a profile pipe, connected in the form of a trapezoid - short tables will reduce the effect of longitudinal bending on the structure.

In the case of a span exceeding 14 m, brakes must be used.

The upper belt should be equipped with a panel length of about 150-250 cm. With the same number of panels, a structure consisting of two strips is built.

For distances greater than 20 m, the metal structure must be reinforced with additional support elements that are connected to the support columns.

In order to reduce the weight of the finished metal, you must take care of the Polonso farm. It includes two triangular shaped systems that are tied with tightening. With this scheme, you can do without large brackets in the middle panels.

When you create a truss with a slope of about 6-10 degrees for a roof with roofs, you must remember that the final design does not have to be symmetrical.

Calculation of a metal bar

Calculations must take into account all requirements for metal structures with national standards. In order to create the most efficient and reliable design, at the design stage, quality drawing, showing all elements of the support, their dimensions and connection to the supporting structure.

Before you get your shelter farm, you need to determine the requirements for the final farm, and then start with the economy, avoid unnecessary costs.

The height of the reed is determined by the type of floor, the total weight of the structure and the possibility of further movement. The length of the metal structure depends on the expected slope (for structures longer than 36 m, the construction lift must also be calculated).

Select the panels so that they can handle the loads that will be displayed on the farm.

Races can have different angles, so this parameter should also be taken into account when choosing boards. In the case of triangular gratings, it is 45 degrees and has a tilt angle of 35 degrees.

The calculation of the roof from the hose profile is completed by determining the distance at which the nodes will be built relative to each other. This indicator usually matches the width of the selected inserts.

Optimal step indicator for overall structure is 1.7 m.

When calculating one farm, it should be understood that its throughput will increase as the height of the structure increases.

How to make cutters from profiled pipes - design options, material selection

In addition, if necessary, a truss scheme with several reinforcements should be supplemented, which can strengthen the structure.

Calculation examples

Getting pipes for metal objects should start with the following recommendations:

• When installing objects with a width of less than 4.5 m, pipes with a profile of 40 x 20 mm with a wall thickness of 2 mm are suitable;
• For sizes from 4.5 to 5.5 m, pipes with a profile of 40 mm with a wall of 2 mm are suitable;
• For larger steel structures, the same pipes are suitable as in the previous example, but with a 3 mm wall or a 60 x 30 mm profile pipe with a 2 mm wall.

The last parameter that must be taken into account in the calculations is also the cost of the material.

First of all, you need to consider the cost of the pipe (remember that the price of a pipe is determined by their weight, not their length). Secondly, it is worth asking about the cost of complex work on the manufacture of metal structures.

Recommendations for the selection of pipes and the creation of metal structures

Before you cook farm and choose best materials For future design, it is worth reading the following guidelines:

• When researching the type of pipes available on the market, priority should be given to rectangular or square products - the presence of amplifiers greatly increases their power;
• When choosing a facade faucet, it is best to choose high-quality steel products from high-quality steel (pipe dimensions are determined by the project);
• Potentiometers and double angles are used to secure the main carrier elements;
• In the upper bands to connect the I-beam frame is usually used on different sides, the smaller of which is needed for the connection;
• For the bottom track, corners with the same sides are suitable;
• The main elements of large structures are fixed with the main panels;
• The races are at 45 degrees and the brackets are at 90 degrees.
• When the metal frame for the crown is welded, it is necessary to ensure that each sound is sufficiently safe (see also: "How to weld a truss from a profile pipe - parameters and rules for calculation");
• After welding, the metal components of the structure remain coated with protective compounds and paints.

conclusion

Profile pipe trusses are very flexible and suitable for a wide range tasks.

Production farms cannot be called simply, but if you approach all stages of work with all responsibility, the result will be reliable and of high quality.

This type of knot is used for the design and verification of tubular connections of steel members with round, square and rectangular sections in accordance with the recommendations of Eurocode 3: 2005.

Knot calculation affects the following pipe connections: k, n, kt, T, Y, and X. You can also use I-beams as a chord in connections and use a cantilever side panels), welded on a belt truss (see ,

Take a look at the picture below.

Calculation methods:

Group of efforts to be taken into account when calculating the city:

• longitudinal forces and moments in the truss chord
• longitudinal forces and moments in adjacent bars (slashes)
• longitudinal force and torque on the farm.

Load capacity test

Methods for calculating the load capacity of individual bars in a joint should be selected based on the following guidelines:

• included in European Code 3: EN 1993-1-8: 2005
• CIDECT Publications
  • Design Guide for Connectors on Hollow Structural Sections
  • Guidelines for the preparation of a rectangular hollow section (RHS) under the prevailing static load.

    Fundamentals of calculation and welding of a slot from a profile pipe

Calculation of welds

It is assumed that testing the power of the NRdi node with a brush is equivalent to testing the strength of these connections.

Therefore, when welding, we consider as fillet welds. Joint strength is tested in accordance with Eurocode 3:2005.

It is acceptable

• in the case of assemblies that are made entirely of round tubes or with x-ray strips,
• and brackets and racks - from a tube of round work,

the length of the weld is equal to their actual length.

If the hose is connected at a flat angle

For belts made from rectangular and square pipes, it is assumed that some sections of the welds are ineffective.

K and N compounds

In case there is a distance between the bars, it is assumed that the longitudinal sections of the seams (relative to the axis of the belt) are fully effective and that the effectiveness of the cross sections is different.

Section 3 (inner weld) of the inclined bars of the assembly participates in the transfer of force from one bar to the adjacent section, and section 4 (outer weld) is excluded from participating in large angles of inclination.

Calculated sections of fillet welds:

a) Calculated wire cross-section for θ > 50°

a) design cross-section of the weld for θ ≤ 50 °

reduced length welded joints in compounds K and N is equal to:

The value of l4 in the interval (50 degrees, 60 degrees) must be linearly interpolated.

In connection with the attachment of rods, it is assumed that welds are counted on all four sides of the pipes to be joined, and their lengths are calculated according to the actual dimensions of the coupling.

Weld lengths in K and N joints:

The procedure for calculating the voltage in separate sections welded joints is the same as for joints with a gap between the rods.

See also:

Distribution of forces and stresses in welded joints

T, Y and X connections

Sections 3 are not efficient if b values ​​are small

It is assumed that the length of the weld is effective:

Roof trusses for housing construction are mainly made of wood, which is exposed to the environment. In places where wood comes into contact with other materials, it is necessary to install gaskets that will serve as a moisture barrier on the side of the roof, vapor barrier on the side of the living quarters. Be sure to install ventilated gaps and treat with flame retardants and an antiseptic.

The roof truss bears all the structural loads of the roof, the weight of the roof, battens and resists external influences.

The roof truss of metal structures is the most durable, reliable and high-quality material that suits absolutely all types of buildings, has a wide area of ​​operation in various climatic zones and weather conditions.

MSL Consulting Group offers roof trusses from metal structures of the following types:

Gable roof truss

The truss system made of metal, where the triangle is based, as the most rigid and most economical design, capable of evenly distributing loads on bearing walls at home and become a load-bearing roofing part. It is created on the basis of accurate calculations, based on the requirements for the construction of the roof. There are a number of structural elements, variations, the use of which affects the variety of types of structures of such trusses. There is a difference in the spans between the supports - the hanging rafters rest on the extreme supports, and the inclined ones have additional support on the middle load-bearing wall.

Roof truss scissors

The original truss structure made of metal, where the lower plane consists of two segments (puffs) with a slope. The lower belt of the truss does not fill the under-roof space. In industrial buildings and many design projects interfloor overlap is not provided. This provides a number of aesthetic benefits. But to perform the main function of resisting the stretching of the rafters, it is necessary to ensure that the angle of inclination of the combined puff is no more than 2/3 of the angle of the rafters.

Single slope roof truss

It is used for arranging a shed roof or for a zone-shaped one, where several slopes are mounted at different levels. Desirable location of the lower part on the leeward side. As a rule, the angle of inclination is lower than that of multi-slope. With a rafter leg length of more than 4.5 m, supports (racks, struts) are necessary.

Beam roof truss with parallel chords

They are used on flat or slightly sloping shed roofs, for arranging a soft roof, for attic and interfloor ceilings or for their reinforcement. The lattice system of triangles makes the truss unchangeable under any load. Suitable for floors and large spans, which makes it the most popular in the field of industrial construction.

Triangular frame roof truss with a rectangular shape

It is used as a mansard truss when arranging a gable triangular roof. In this case, part of the truss system is the frame of the attic. metal beams interfloor overlap can serve as a puff. Has mass constructive solutions based on the use of additional struts and runs.

Attic roof truss with straight studs

Used in construction gable roof for arranging part of the under-roof space as a living space, if necessary, creating additional space. The design has two parallel beams-racks and horizontal contractions that form the geometry of the living space. The strut system is made outside of it.

Roof truss scissors. Type T

Scissor truss, the middle segment of the lower plane of which has no slope and is made horizontally. The central post under the ridge run transfers the horizontal stress to the lower chord of the truss, reducing it to zero. Additional racks allow you to increase the width of the run, the struts form all the same angles - the basis of a reliable design and distribute the remaining load. Rafters have two extreme supports.

Mansard roof truss with straight studs

A design with broken slopes for those cases when it is impossible to fit an attic room into a simple triangular roof. When installed on a single-span house, it is necessary to strengthen the contractions of the risers of the lower and upper belts (which serves as an interfloor overlap). If there is additional support from inner wall, it's not obligatory. The living space here is formed by parallel fights and racks. The truss is without a central support, and this leaves room for a free attic layout.

Mansard truss with high tightening position and non-slab forming

Broken slopes form two angles of inclination - gentle and steep, which is ideal for arranging a spacious attic. There is no "deaf" zone. The design feature of the truss is the overhanging rafters, due to which the trusses are supported through the corner struts on the longitudinal walls with a fixed Mauerlat. The complex truss system at the top of the struts and struts that form triangles requires an accurate calculation of stress and load distribution. The high position of the puff connecting the rafter legs causes high requirements for fastenings and for the power of the puff itself, since it reduces the bursting force of the metal rafters.

Types of metal trusses

1. Universal roof trusses 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 roof 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 truss by 4-6%.
3. Triangular roof trusses are used for residential buildings when the roof slope is planned to be quite steep.

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.

Roof truss installation

Before installation, the LSTK roof truss is assembled on the ground and raised to the required height in ready-made, then the structure is fixed on the frame of the building.

Installation is carried out in several stages:

1. Installation of braces of the upper beam on the ground (geometrically aligned with the lines of the runs). Connections are made using self-tapping screws.
2. Fixation by a ground brace of the first truss in a given position.
3. Install all subsequent farms in the same way.
4. Installation of braces and lintels on beams.
5. Fixing linear connections between beams and braces.

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 from arched trusses

Farm types

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).

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:

• lean-to;
• gable;
• straight;
• arched.

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 aesthetic appearance. But arched structures require the most accurate calculations, since the load on the profile must be distributed evenly.

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).

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 a suitable roof configuration, taking into account the dimensions of the structure, the optimal number and angle of inclination of the slopes. It is also necessary to determine which chord 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 correctly calculate the design without the relevant knowledge, therefore it is recommended to find an example of calculating a typical farm of the desired configuration and substitute the necessary values ​​\u200b\u200binto 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.

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 is selected and optimal angle the slope of the slope (or slopes).
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. On next step the distance between the nodes should be determined (usually it corresponds to the width of the panel). If the span length exceeds 36 meters, the calculation of the building lift is required - a back-suppressed bend that 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.

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 on the example of a proposed structure with a span between supporting structures(L) 6 meters, step between arches 1.05 meters, truss height 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°.

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

mn = π×R×α/180, Where:

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:

mn \u003d 3.14 × 4.1 × 106 / 180 \u003d 7.58 m

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

To prefabricated structures ceilings, primarily large-sized ones, withstood 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 the best option, taking into account the configuration of the section and wall thickness of the elements, the design features of the truss.

Farms are recommended to be made of high quality pipe, for arched structures it is desirable 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 alloyed steel do not require additional protective painting.

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 at the construction site. If there are no skills welding work, it is recommended to invite a welder with professional equipment.

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 assembled frame using corners and overlay plates where 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.

In order to assemble a farm from a profile pipe, it is necessary to use lattice rods. The process itself is quite laborious, compared with structures consisting of solid beams, but it is also worth paying attention to their efficiency. It is the paired material that is used to make the truss structure, while the scarves act as a practical and fairly high-quality material using riveting and welding.

Thus, it is possible to block the span of almost any length, but do not forget about the need for serious installation work, which will require a considerable amount of experience and specific knowledge. Without correctly carried out preliminary calculations of the trusses themselves, a lot of errors and subsequent costs will follow from the profile pipe.

If all the previous conditions have been met correctly and the quality of welding work has been performed at the proper level, it is necessary to install the structure at a previously prepared place and carry out installation work aimed at top harness following the predefined markings.

Characteristic advantages of load-bearing trusses from a profile pipe:

• Long service life;
• Significant savings, both personal time and money;
• Fairly insignificant weight;
• The material allows you to build a structure of almost any shape;
• Such a design is designed for significant loads of a constant type;
• Endurance.

The main structure of the truss from a profile pipe

Such structures as trusses from a profile pipe are divided into several types. The subspecies are based on selections of various parameters. One of the main ones is the number of belts.

• Hanging structures, which are based on several belts. Depending on the location, they are called either upper or lower;
• A number of structures whose main components are in a single plane.

According to the form, the structures can be separated:

• Arched type, which is based on an unusual and convex shape;
• They can also be straight;
• gable and shed structures made from a profile pipe.

Based on the variability of the contours, there are:

These types of farms are divided according to the angle of inclination, there are three main groups:

• If the angle equates to 22*-30*. The ratio of length and height is equal to one to five. They are quite popular in domestic construction, as one of the most acceptable ways to cover spans of small height. Relatively insignificant weight can be called one of the undeniable advantages. For other analogues, it is better to use triangular trusses.
• Spans, whose length exceeds the mark of 14 m, it is recommended to additionally use braces installed in the direction from top to bottom. On the topmost layer there will be a panel, the length of which can vary from 150 to 250 cm. As a result, the initial data will be a design, which will include several belts. The number of panels will remain even.
• But if the span is more than 20 m, it is worth using a sub-rafter structure, the auxiliary components of which can be called support columns.

Special attention I would like to pay attention to the design of the Polonso-type truss. With its help, it is possible to eliminate the defect of the so-called long braces, which lead to a decrease in the total weight. The profile pipe truss consists of two or more triangular systems, which are connected to each other by tightening.

• Less than 15*. Practice has shown that in order to achieve maximum efficiency profile pipe trusses, it is better to use trapezoidal rafters made of durable metal. The presence of short racks will help to avoid further formation of a longitudinal bend;
• No more than 22*. Parities of length and height should be equated as seven to one. The maximum length of a truss from a profile pipe should not exceed 20 m. If for any reason this mark needs to be increased, then the lower belt becomes broken.

Pay Special attention!

The asymmetric shape is preserved if the angle of the roof of the truss from the profile pipe fluctuates between 6-10 *.

The very height of the truss can be determined by the formula for splitting the length of the span itself into seven, eight or nine parts, this figure will depend on the design feature you have chosen.

All necessary calculations farms are required to be produced, following established instructions SNiP:

• the basis of any calculation is a correctly performed calculation of the truss itself made of a profile pipe. Preparation of a truss scheme from a profile pipe involves the calculation and further indication of the ratio of the roof slope and the length of the structure.

If the length of the truss is more than 36 m, the level of the construction lift must be additionally taken into account in the calculations.

The size of the selected panels should directly depend on the type and volume of further loads on the structure. It is worth remembering that the angles of the braces will directly depend on the rafters used, but the panel must fully comply with them. For a triangular lattice familiar to everyone, the angle will be equal to 45 *, but for a diagonal one only 35 *.

The final step in calculating the truss from the profile pipe should be an indicator characterizing the gap between the obtained angles. Ideally, it should match overall width panels.

Absolutely all calculations of a truss from a profile pipe must be performed in such a way that, as a result, even the slightest increase in height leads to an increase in the bearing feature of the entire metal structure. If you choose the right angle of inclination, then snow masses will not linger on its surface for a long time. Installing additional stiffeners will help strengthen the truss itself, which is one of the most acceptable ways to increase the efficiency of the structure as a whole.

For precise definitions regarding the dimensions of the device for awnings, you should be guided by the following information:

• For structures, the dimensions of which will be 4.5 m, in this case, components will be used, the dimensions of which will be 40x20x2 mm;
• Over 5.5 m, the dimensions of the products will be 40x40x2 mm;
• For buildings whose dimensions are more than 5.5 m, the most acceptable would be the use of structures whose dimensions are 40x40x3 mm. But it is possible to use 60x30x2 mm.

When it comes to measuring the step, the maximum allowable length from the canopy to one of the supports is 1.7 m. If this principle is not followed, such indicators as the reliability and strength of the structure will remain in question.

Calculation of a truss from a profile pipe can be made using our online calculator.

After obtaining all the quantities, using special devices and the previously mentioned formulas, one can obtain ready scheme future farm from a profile pipe. Subsequently, you should think about further carrying out the necessary welding work in order to weld the truss from the profile pipe correctly.

How to do right choice and make a farm from a profile pipe correctly:

• When choosing a certain size according to the established types, for a start it is better to opt for square or rectangular trusses from a profile pipe, which have several stiffeners, which in turn will provide maximum stability;
• Worth using exclusively quality products and products purchased from trusted suppliers. Such structures are not prone to corrosion and are sufficiently resistant to various climatic factors. The dimensions and wall thickness are made based on the data laid down in the initial project. Only by carrying out all these manipulations can the necessary bearing capacity of the rafters themselves be ensured;
• Versatile I-type corners are used for the upper belt. Docking is performed in the direction based on the smaller wall;
• As a pairing, it is customary to use paired corners and special tacks;
• In order to fasten the parts located in the lower belt, equilateral corners are used;
• The remaining parts can be connected using overhead plates of different diameters.

The braces must be installed at an angle of 45 *, but the racks are exclusively at a right angle. After finishing initial stage farm assembly from a profile pipe, you can proceed to the farm.

Each of the formed seams is checked for quality separately, since only they can guarantee required level reliability of the entire structure of the future building or structure. After completion of welding work, the rafters are treated with a substance with an anti-corrosion composition and opened with paint.