Metal structures consisting of lattice rods and profile pipe are called farms. Used for production paired material, connected by special scarves. To assemble such a structure, welding is mainly used, but riveting is sometimes used.

The truss helps to cover any span. Length has no of great importance. But in order to correctly perform such installation, competent calculation is required. If the welding work is completed efficiently and the plan is made without errors, all that remains is to deliver the pipe assemblies to the top. Then install them according to top harness, strictly according to the markings.

Canopies can be made from a variety of materials:

Tree;
Concrete;
Aluminum;
Plastics.

However, in most cases, the truss frame is made of a special profile pipe. This hollow structure differs from others in its high strength and simultaneous lightness. The cross-section of such a pipe can be:

Rectangle;
Square;
Oval;
Polyhedron.

For welding, trusses most often use a rectangular or square cross-section. This profile is less labor-intensive to process.

The maximum loads that a pipe can withstand depend on several factors:

Wall thickness;
Type of steel;
Preparation method.

Profile metal pipes made from special structural steel (1-3ps/sp, 1-2ps(sp)). Sometimes, when certain circumstances arise, galvanized steel or low-alloy alloys are used.

Pipes with a small cross-section are available in lengths of 6 meters. The length of large sections reaches 12 meters. The diameter of the pipe can be very different. The following are considered minimal:

10x10x1 mm;
15x15x1.5 mm.

The thicker the wall, the higher the strength of the profile. For example, products with very large dimensions (300x300x12 mm) are mainly used for construction industrial buildings.

Dimensions of frame parts

Small-sized canopies, the width of which is less than 4.5 meters, are made of profile pipe with dimensions 40x20x2 mm.

With a width of about 5.5 m, craftsmen advise installing a pipe with a cross-section of 40x40x2 mm.

If the length of the canopy is large, it is recommended to use pipes:

40x40x3 mm;
60x30x2 mm.

What to pay attention to when calculating

Before you start calculating the cross-section of the pipe, you need to determine the optimal type of roof. The choice is influenced by its dimensions, the angle of the roof and the contour of the belts.

These above components depend on several conditions:

Functionality of the building;
What material are the floors made of?
Roof slope angle.

Then the dimensions of the pipe are determined. Depending on the angle of inclination, the length is selected. Determination of the height is influenced by the brand of material from which the ceiling will be made.

The dimensions of the pipe also depend on the method of transportation and the total weight of the entire metal structure.

In the case where the calculation of a truss made from a profile pipe has determined that the length will exceed 36 meters, it is necessary to additionally calculate the construction lift.

Then the dimensions of the panels are determined. All calculations are based on the load that the structure must withstand. For a triangular roof, the slope should reach 45 degrees.

The calculation is completed by determining the exact distance between the elements of the metal structure from the profile pipe.

It is quite difficult to accurately plan everything in numbers without special knowledge. Therefore, it is better to turn to professionals who will carry it out on a computer. They always guarantee the high quality of their services.

Before starting construction, it is worth checking all calculations again, taking into account the maximum load that the structure can experience.

In addition to the calculations made, the quality of installation depends on the correctness and accuracy of the plan drawings.

Free calculation programs

The website http://rama.sopromat.org/2009/?gmini=off offers to calculate the truss using an online program using the finite element method. This calculator can be used by students and engineers. The program has a clear interface that will help you quickly perform the necessary actions. The calculation can also be done partially free program on the website http://sopromatguru.ru/raschet-balki.php

In what sequence are the works performed?

To assemble the frame, you must use the services of an experienced welder. Assembling a farm is considered a very responsible task. You must be able to cook competently and understand truss welding technology.

It is very important to know exactly which units are best assembled at the bottom, and then lifted and secured to supports. To work with a heavy structure, you will have to use special equipment.

First, the area is marked;
Embedded parts are mounted;
Vertical supports are being installed.

Quite often, metal pipes are lowered into a trench and then filled with concrete. A plumb line is used to check the verticality of the installation. To control parallelism, a cord is pulled between the last posts. All others are set according to the received line.

By welding, longitudinal pipes are welded to the supports.

The truss parts are welded on the ground. The belts of the structure are connected by jumpers and special braces. Then the finished blocks are raised to a certain height. They are welded to the laid pipes in the places where vertical supports are installed.

Longitudinal jumpers are welded between the trusses directly along the slope so that the roofing material can be fixed. Mounting holes are made in advance in the jumpers.

The connecting areas are well cleaned. This is especially true for the upper part of the frame, on which the roof will then be applied. Then the surface of the profiles is processed. Performed:

Cleaning;
Degreasing;
Primer;
Coloring.

Entrance door and canopy

To calculate the dimensions of the cantilever canopy, you need to take into account the size of the porch. According to established standards, the size of the upper platform must necessarily exceed the width of the door (1.5 times). With a blade width of 900 mm, it turns out: 900 x 1.5 = 1350 mm. This should be the depth of the roof located above the entrance. In this case, the width of the canopy must exceed the width of the steps by 300 millimeters on both sides.

Cantilever awnings are most often installed over the entire area of the porch. They should cover the steps. The number of steps affects the size of the roof depth. The average value is determined according to the established SNiP standards: 250-320 mm. The size of the upper platform is added to this size. Moreover, the width of the canopy has a regulated value. The width of the steps is taken within the range (800-1200 millimeters), and 300 mm is added to it on two opposite sides.

We calculate the dimensions:

Standard cantilever visor – 900-1350 mm by 1400-1800 mm.
Cantilever-supported canopy over the porch, example of calculation for 3 steps and a platform: depth (900/1350 + 3*250/320) = 1650 – 2410 mm, width 800/1200 + 300 + 300 = 1400-1500 mm.

How are verandas calculated?

Typically such structures are located along the wall of a building. Several types of structures remain relevant for them:

Beam-supported;
Console.

The smallest depth is 1200 mm. 2000 mm is considered ideal. This distance corresponds to the location of the support pillar.

The calculation of the roof according to the perpendicular will look like 2000+300 mm. However, flat roofing is more suitable for areas where rainfall is minimal.

If the slope angle = 30 o. the leg adjacent to it (perpendicular depth of the canopy roof) is 2300 mm, the second angle is 60 degrees. Let's take the 2nd leg as X, it lies opposite the angle of 30 degrees. and according to the theorem is equal to half the hypotenuse, hence the hypotenuse is equal to 2*X, we substitute the data into the formula:

(2*X) 2 = 2300 2 + X 2

4*X 2 - X 2 = 5290000

X 2 (4-1) = 5290000

3*X 2 = 5290000

X 2 = 5290000.3

X 2 = 1763333, (3)

X = √1763333, (3) = 1327 mm – leg that will be adjacent to the wall of the house.

Calculation of the hypotenuse (roof length with slope):

C 2 = 1327 2 + 2300 2 = 1763333 + 5290000 = 7053333

C = √7053333 = 2656 mm, we check: the leg lying opposite the angle of 30 o is equal to half the hypotenuse = 1327*2 = 2654, therefore, the calculation is correct.

From here we calculate overall height canopy: 2000-2400 mm - this is the minimum ergonomic height, we calculate it taking into account the slope: 2000/2400 + 1327 = 3327/3737 mm - the height of the canopy wall near the house.

How to calculate parking

Typically, beam structures are installed. To make a canopy for your car with your own hands, you must first make a drawing, which should take into account the class of the car. The width of the parking lot should be equal to the size of the car, plus one meter on both sides. If two cars are parked, it is necessary to take into account the distance between them - 0.8 meters.

An example of calculating a canopy for a middle-class car, width – 1600-1750 mm, length – 4200-4500 mm:

1600/1750 + 1000 + 1000 = 3600/3750 mm – canopy width;

4200/4500 + 300 +300 = 4800/5100 mm – ergonomic length so that precipitation does not flood the site.

Calculation of the width of the canopy for two cars:

3600/3750 + 800 = 4400/4550 mm.

Gazebos

Typically, such a canopy is made in the depths of a personal plot. These structures are installed on a foundation, which can be:

Pile;
Columnar;
Tape;
Tiled.

The choice of foundation type is influenced by the size of the building, as well as the nature of the soil. These values must be shown on the drawing. The installed gazebo can have several sizes:

3x4 meters;
4x4 meters;
4x6 meters.

To independently calculate such a structure, to design a drawing, you need to take into account several parameters.

For one person to relax comfortably, 1.6-2 square meters is required. meter of floor area.

When installing a barbecue directly under a canopy, the recreation area should be separated from it by a free area. Its width is 1000-1500 mm.

The width of a comfortable seat is 400-450 mm.

Table dimensions 800x1200. The calculation is per person (600 -800 mm). For a large number of people, the size can reach 1200x2400 mm.

Trusses made from profile pipes have many advantages. With their help, nowadays they build residential buildings of any configuration, garages, as well as some household structures. They are also used to create greenhouses. In terms of their cost, farms are not at all expensive for land owners. They are quickly constructed and attached to load-bearing elements. To securely fasten this structure you will need a high-quality profile, a welding machine, an angle grinder and care in the design.

Anyone who decides to use this type of construction on their building should have a clear plan consisting of:

Choosing the right profile;
Clear calculation of the farm;
Correct placement of jumpers;
Reliable installation.

At its core, a truss is a unique structure that connects supporting elements and, as a result, forms a finished frame. Among experts, it is considered a simple architectural metal structure. This configuration has many advantages:

The strength of the entire frame and separately the truss itself;
High performance characteristics;
Reasonable cost taking into account the prices of pipes and consumables;
Excellent resistance to external influences, deformation.

Trusses made from profile pipes have gained great popularity due to the fact that they are ideal for creating strong supports for any type of roof. Moreover, these indicators are not affected by the weight of roofing materials.

Roof trusses can have completely different shapes structures and arbitrary braces. For example, for garden buildings they use a lean-to form. It is easy to install, and this configuration can withstand the most various loads. Gable samples are more suitable for garages and houses.

An arched truss is also distinguished by its shape. It has a convex shape and is considered one of the most durable.

For correct calculation farms must follow certain rules.

Making trusses will not take much time. It all starts with choosing quality material. It will determine the durability of the entire structure. All metal parts are connected using tacks, as well as special paired corners.

Corners with equal sides are mounted only in case of mating parts.

The racks are attached at an angle of 90 degrees, and the braces - 45 degrees.

Example of a finished truss design

Requirements for calculating a profile pipe for the construction of a farm

Primary requirements:

Calculations are made using all measurements of the length of the structure and the angle of inclination of the roofing material. Farm preparation should begin only after clear measurements of indicators have been taken.
The exact dimensions depend on many factors. A certain type of structure will be determined based on the weight of the entire product, the load, the height of the roofing material, as well as the methods of its movement. Only the length of the workpiece determines the angle of the roof.
It is initially necessary to include supports in the calculations and clearly define their belts. Length matters. The contours also depend on the slope and type of structure.

This is mainly responsible for two legislative documents that determine the calculation procedure. One contains information about exposure standards and permissible loads, and the other will help determine the type of steel structure. With their help, the calculation of a truss from a profile pipe can be carried out quickly and as correctly as possible.

The most important thing to take into account is that the calculation is made on the principle of economy. After determining the span height, length and angle of inclination of the entire structure, the calculation ends with the last point - establishing optimal distance between all components. The span load affects the amount of material and its location.

Calculation of an arched truss from a profile pipe

Define optimal values structures can be found at specific example arched truss. The length of the structure is 600 cm. Each section is located at a distance of 105 cm from each other. The height of the arched ceiling is 300 cm. The boom of the lower belt in such a product will be equal to 130 cm. The radius of the circle at the bottom will be 410 cm. According to the calculation conditions, the angle between the radii is 105.9776˚.

Designations:

mn – the length of the profile that is necessary for laying the lower tier;

π – constant value;

R – radius.

To calculate the required indicator, experts use a certain formula:

The result is the following calculation:

mn=3.14×4.1×106/180 = 758 cm.

It should be noted that the step between the points at the corners will be 55 cm.

A clear example demonstrates that trusses made from profile pipes are calculated quite simply and quickly.

Calculation example

Training video with calculation rules.

Features of the design of a truss made of profile pipes

The profile pipes from which the trusses are made are durable and therefore have distinctive characteristics. The features of all designs are divided into several main factors.

The number of belts and the load indicator are considered critical indicators.

According to these characteristics, farms are divided into:

A type of configuration in which all elements are located in the same plane;
A type in which individual parts of the span are located in two or more tiers.

Both design features are stable and can withstand extreme loads, while the angle of inclination can be arbitrary. But to ensure a longer service life for the structure, it is recommended to use the second type. It's more reliable.

Trusses made from profile pipes are also designed depending on the contours and their shapes. As mentioned earlier, according to the last criterion, structures are divided into single-pitch, gable, straight, and also in the shape of an arch. Each of the samples is used for different purposes.

For example, products with a parallel belt are ideal for soft roofing. The support is quite simple and all its parts are identical. It is the easiest to install, since this process does not require special knowledge.

Single pitch metal trusses the best way suitable for fastening a rigid roof at the required height.

W-truss

Types of profile pipe trusses

There are many different types of trusses that allow you to implement a wide variety of design solutions.

The first and most common variety is the triangular shapes of metal structures. This is a classic type of workpiece, suitable for structures of various types. In order to select the optimal cross-section of pipes in such a sample, it is necessary to take into account the characteristics of the further operation of the structure and its nominal weight. Length is also taken into account. The advantages of such products are strength, ease of installation and constant supply. natural light through triangular frames.
The second most popular type is polygonal trusses from a profile pipe. This configuration is indispensable in large rooms. When to design large building or a canopy, it is polygonal products that meet all the requirements. The only disadvantage of such structures is the difficulty in welding them. Despite the usual angle of inclination, it is necessary to use a certain welding principle and technique. And this is not suitable for lightweight structures.
In terms of strength characteristics, the truss, which has parallel belts. A distinctive feature of this metal structure is that all the rods, gratings and belts are of the same length. It is considered the easiest to calculate.
Also a reliable type of farm - single slope trapezoidal shape. Such trusses rest on columns. In terms of its rigidity characteristics, this type has no equal.

Types of farms

The main structure of a truss made from a profile pipe

Experienced specialists can assemble trusses from profile pipes quickly. To do this, it is necessary to provide exact dimensions and drawings of the metal structure. But, if the goal is to save the construction budget, you can do the installation yourself. To do this, you first need to assemble the main structure.

In order to create it, they use mainly rectangular or square hardware. They allow the entire workpiece to remain strong throughout its entire service life. In addition to this, the main structure of square profile easier to attach to the base.

The first stage, using drawings and calculations, is to weld all the metal parts of the truss itself. This is done on the ground or in a prepared room with smooth floors. The length and width of the product are checked.

This is followed by the stage of installing and fixing the supporting elements located vertically. Their correct installation determines the reliability of the entire metal structure. You can use a plumb line to check. It will show how accurately the load-bearing supports were secured.

How to weld trusses from a profile pipe

As soon as the supports are ready, longitudinally located pipes are welded to the posts. They are attached for reliable coupling of the elements. They give the entire structure stability.

When the base is ready, it is time to attach a truss from a profile pipe to it. The pre-prepared configuration with gratings is lifted and installed on top. You should immediately check the correct assembly, including the braces. All corners must be in place and fit snugly to the base. When all dimensions and location of the structure have been checked, metal elements welded to each other. Don't forget about potholders.

Connection example

Ultimately, it is necessary to clean all connecting places where the welding machine was used and carefully paint all parts of the metal structure.

As a result, correct calculations, quality materials and attentive welding work allows you to create the perfect overlap.

Video explaining the welding process of the structure:

Sooner or later, the owners of a private house need to build a carport or summer holiday, a gazebo, a small fence with a roof for pets, a canopy over the woodpile. In order for the roof over such a structure to be securely fastened, it is necessary to correctly design and install metal supporting structures.

We welcome our dear reader and offer him an article about what profile pipe trusses are, how to correctly calculate and install them.

A truss is a structure of rectilinear elements connected to each other at nodes into a durable system of unchangeable geometric shape. Most common flat designs, but in large loaded structures, volumetric (spatial) trusses are used. Almost in private houses, farms are made of wood and metal. Small structures of rafters, canopies, and gazebos are made from wood. But durable and high-tech metal is an almost ideal material for load-bearing metal structures.

For the manufacture of complex structures Solid rolled products and pipes are used. Profile pipes (square, rectangle) have greater resistance to crushing and bending; small structures for the house are mounted without welding, therefore, for manor buildings, a profile pipe is most often used.

Structural features of trusses

Components of the truss structure:

Belt.
Stand – vertical element, connecting the upper and lower belt.
Brace (brace).
Sprengel - support brace.
Grills, overlays, gussets, rivets, bolts - all kinds of auxiliary and fastening materials.

The height of the truss is calculated from the lowest point of the lower chord to the highest point. Span - the distance between supports. Rise is the ratio of the height of the truss to the span. The panel is the distance between the nodes of the belt.

Types of trusses from professional pipes

Farms are divided according to the outline of the belts. There are two-band and three-band varieties. In small structures, simpler two-belt trusses are used. Each variety has a certain slope and height depending on the length of the span and the shape of the truss.

Types of trusses according to the outlines of the chords: beams with parallel chords (rectangular), triangular (gable and single-pitch), trapezoidal (gable and single-pitch), segmental (parabolic), polygonal (polygonal), cantilever; with a broken raised or concave lower belt and a varied shape of the upper belt; arched with horizontal and arched lower belt; complex combined forms.

Trusses are also distinguished by types of gratings - see in the figure. In private buildings, triangular and diagonal grilles are most often found - simpler and less metal-intensive. Triangular gratings are usually used in rectangular and trapezoidal structures, while diagonal gratings are used in triangular ones.

Before erecting any structure, you should decide on the choice of material. At the time of buying metal profile or pipes, you should carefully inspect the workpieces to see if there are any cracks, cavities, sagging, inconsistencies along the seam, or a large number of dented and bent workpieces. When purchasing galvanized materials, it is advisable to check the quality of the coating - whether there are any peelings or sagging.

When purchasing, you must request a copy of the certificate and a receipt. It is imperative to ensure that the pipe wall thickness corresponds to that stated in the documents. You can’t make pipes in a garage on your knees, and there are no fakes, but you can come across poor quality material, so it’s better to buy in fairly large stores.

What material to choose for the frame

In most cases, steel is chosen for the frame of manor buildings or the roof of a house. For very small structures, aluminum is sometimes used, usually in purchased products (awnings, rocking chairs). For the construction of metal structures, you can use pipes of hollow section and solid section profiles (circle, strip, square, channel, I-beam).

A huge advantage of rectangular and square pipes compared to a profile of the same weight is their high resistance to crushing and other deformations. Therefore, solid profiles can be replaced with much lighter corrugated pipes - this greatly simplifies (2 times or more) and reduces the cost of a tubular type design.

The cross-sectional dimensions of the pipes are selected depending on the span length and the distance between the supports and trusses. In private estates, sheds and other structures are not very large, and you can take the advice of experts or find ready-made drawings on the Internet.

With a distance between supports of up to 2 m, for small canopies with spans up to 4 m long, profiles of 40x20x2 mm are suitable, for spans of up to 5 m - 40x40x3, 60x30x3 mm; spans longer than 5 m – 60×40x3, 60×60x3 mm. If you are planning a carport for two cars with a width of 8-10 m, then a profile will be required from 60x60 to 100x100 with a wall thickness of 3-4 mm. The profile dimensions depend on the distance between the trusses.

Corrugated pipes are sold in lengths of 6 and 12 m. With a length of 12 m, metal is consumed more economically, but transporting such pipes requires a long length. Before purchasing materials, you should think about how you will cut the blanks and how many of them will fit in a pipe 6 m or 12 m long, and calculate how many sections of corrugated pipe you will need.

You cannot rely on the nominal weight - the weight is 1 m.p. in a particular batch will differ from the nominal one, and most likely upward (it is more profitable for sellers to produce products with a thicker wall - the price is per ton). When purchasing by weight, the material will have to be purchased and transported - and this is an extra expense.

Advantages and disadvantages of different metals

In practice, the following types of steel are used for structural profile pipes: carbon of ordinary quality and high-quality, structural, alloyed. Pipes come with a protective zinc coating. Aluminum is also used - but rarely, for small, often seasonal structures. Aluminum profiles used for small structures.

Traditionally, for small structures in a private estate, carbon steel St3sp, St3ps, and sometimes galvanized, is used for the construction of steel structures with trusses. This steel has sufficient strength to ensure the reliability of the structure; there is practically no difference in corrosion resistance between all three types of steel.

If structures are exposed to precipitation, sooner or later both structural and alloy steel products will rust. A small amount of alloying elements does not protect against corrosion (for structures, low-alloy steels such as 30KhGSA, 30KhGSN, 38KhA can be used - the content of alloying elements in them is 2-4%, and this amount does not affect corrosion resistance).

In terms of strength, structural and alloy steels should be slightly more durable than carbon steels - they are more resistant to cyclic loads. But this quality in steels manifests itself after heat treatment - and quenching and tempering can warp pipes, and usually no one does such heat treatment on finished products. On seamless pipes annealing can be carried out - after annealing, residual stresses in the metal are removed (hardening), but it becomes softer.

Structural steels (20A, 45, 40, 30A) have a higher quality and a higher price. Alloy steels are even more expensive (and there is a chance that they will sell you pipes made from steel 3 instead of alloy steel). Therefore, when installing structures less than 20 m wide, it does not make sense to buy professional pipes made of alloy or structural steel. It definitely makes sense to use galvanized corrugated pipe if the installation will be carried out using crab systems.

If installation is carried out by welding, the welds will rust as quickly as ordinary uncoated metal. But if you carefully monitor the seams and regularly carry out anti-corrosion treatment (cleaning, priming, painting), then a galvanized pipe is preferable. If you need a temporary shed for 10 years for building materials, and then you will demolish the shed, don’t bother, buy ordinary carbon steel pipes without coating.

If you plan to build on a plot of very large canopy or a hangar with a long span, it is worth contacting professional builders and make a project - they will determine which steel you should choose.

Make it yourself or order it

Trusses for a carport or gazebo roof have small sizes and a simple design - most often triangular with several struts and racks. You can complete such a design yourself if you have at least basic welding skills and are not afraid to learn new jobs.

But making trusses requires accuracy, an assistant, a very flat area on the estate for laying out and welding structures, a welding machine and time. You can order ready-made structures from a factory or construction company and install them yourself.

Requirements for calculating a profile pipe for the construction of a farm

When calculating the dimensions and wall thickness of profile pipes required for the construction of your metal structures; the following conditions are taken into account:

Dimensions of the metal structure, and in particular, length, support spacing - the distance between supports.
Height of supports and trusses.
Farm shape.
Possible features of geological conditions (seismic activity, possibility of landslides).
Coating weight.

What happens if you calculate incorrectly

If the calculations are incorrect, the following consequences are possible:

Farm structures will deform under the weight of snow and wet leaves.
In the worst case, the structures will deform under their own weight.
The entire structure may collapse in strong winds.
Deformation will sooner or later lead to the destruction of the truss and the entire structure, which is dangerous for humans and can damage objects located under the canopy - a car, for example.
A fragile and movable structure will lead to the destruction of the roof laid on the truss.
When using a profile that is too powerful and heavy, the costs of materials and work during the construction of metal structures increase unjustifiably.

We design a farm and its elements

A complete and accurate calculation of the load on a truss along with diagrams is complex, and to perform it you should contact specialists.

When designing large canopies, hangars, and garages made of metal structures, an accurate calculation of the required profile is necessary, but for the construction of not too large canopies or gazebos in a private estate, you can use the well-known recommendations of experts.

For very small structures (a canopy in an animal enclosure, a canopy over a firewood store), it is enough to use pipes measuring 40x20 mm with a wall thickness of 2 mm; for gazebos and canopies over tables, barbecues or recreation areas - 40x40 mm with a wall thickness of 3 mm; canopy over a place for a car - from 60x40 to 100x100 mm with a wall thickness of 3-4 mm.

If the canopy has several trusses and supports and the support spacing is less than 2 m, you can take a thinner pipe; if there are only 4 supports and two trusses and the span length is 6-8 m or more, you can take a thicker one.

Permissible loads on trusses are given in the table:

Span width, m Pipe size per wall thickness, mm	1	2	3	4	5	6
For profile pipe
40×40x2	709	173	72	35	16	5
40×40x3	949	231	96	46	21	6
50×50x2	1165	286	120	61	31	14
50×60x3	1615	396	167	84	43	19
60×60x2	1714	422	180	93	50	26
60×60x3	2393	589	250	129	69	35
80×80x3	4492	1110	478	252	144	82
100×100x3	7473	1851	803	430	253	152
100×100x4	9217	2283	990	529	310	185
120×120x4	113726	3339	1484	801	478	296
140×140x4	19062	4736	2069	1125	679	429
For a rectangular pipe (with the larger side vertical)
50×25x2	684	167	69	34	16	6
60×40x2	1255	308	130	66	35	17
80×40x2	1911	471	202	105	58	31
80×40x3	2672	658	281	146	81	43
80×60x3	3583	884	380	199	112	62
100×50x4	5489	1357	585	309	176	101
120×80x3	7854	1947	846	455	269	164

Drawings and diagrams

When manufacturing metal structures, drawing with exact dimensions is mandatory! This will allow you to purchase required quantity material, will save time when assembling and preparing workpieces, and will allow you to easily control the dimensions of the metal structure during installation and the finished structure. IN in this case The safety of you and your household depends on the accuracy of the assembly - a structure that collapses due to snow or wind can bring a lot of trouble.

Truss Calculation Basics

The types of trusses depend on the shape of the roof, and the shape of the roof of a structure on an estate is chosen depending on the purpose and location of the metal structures. Cantilever trusses and farms adjacent to the house are usually made with single-pitched triangular ones, free-standing canopies - with polygonal, triangular, segmental structures and arches. Gazebos can have a six- or eight-slope roof or a fantasy roof with trusses of a non-standard design.

To calculate the trusses, it is necessary to calculate the load on the roof and on one truss. The calculations take into account the load of snow cover, roofing, sheathing, and the weight of the structures themselves. Accurate calculations are a task for a professional builder. The basis for the calculation is SP 20.13330.2016 “Loads and impacts. Updated version of SNiP 2.01.07-85" and SP 16.13330.2011 " Steel structures. Updated edition of SNiP II-23-81".

For calculations, the cutting method is used: cutting out nodes (areas where the rods are hingedly connected); Ritter method; Henneberg rod replacement method. In modern computer programs The method of cutting out knots is more often used.

It's better to use a ready-made one standard project or our recommendations for choosing profiles. Assembling a truss of a simple trapezoidal or triangular structure is not too difficult, and if you have experience in welding and installing metal structures self-installation awnings and gazebos are quite possible. If you want to build a large shed with a truss length of 10 m or more, you need to complete the project with specialists.

Influence of inclination angle

The design of the truss is primarily affected by the angle of inclination of the ramps (ramp). The angle of inclination is selected primarily depending on the shape of the roof and the placement of the metal structure. Sheds adjacent to buildings should have a larger roof angle to allow snow sliding off the roof to roll off more quickly and flowing water to drain away.

For single structures, the roof slope may be less. The angle of inclination also depends on the amount of precipitation that falls in your region - the more precipitation, the greater the angle of inclination of the roof should be. The steeper the roof, the less precipitation it retains.

A slight slope of the slope - up to 15° - is used on small free-standing sheds. The height of the slope is approximately equal to 1/7-1/9 of the span length. Trapezoidal trusses are used.

Slope from 15° to 22° - the height of the slope is 1/7 of the span length.

Slope from 22° to 30°-35° - the height of the slope is equal to 1/5 of the span length; with this slope, triangular structures are usually used, sometimes with a broken lower chord to make the structure lighter.

Base Angle Options

To correctly calculate the number and lengths of individual elements of a corrugated pipe truss, it is necessary to determine the base angles between the elements. In general, the lower chord is perpendicular to the supports, the upper chord is inclined to the horizontal depending on the angle of the roof. The optimal angle of inclination of the braces to the horizontal/vertical is 45°, the racks must be strictly vertical.

The exact angle of inclination of the roof is either specified by the project, or is found according to the relationships given above ( for a slope of up to 15° - the height of the slope is approximately equal to 1/7-1/9 of the span length; for a slope from 15° to 22° - 1/7 of the span length; for a slope from 22° to 30° - 35° - the height of the slope is equal to 1/5 of the span length).

Having determined the exact angle of inclination of the roof, the lengths of the blanks for making the truss are determined - this information will be required when performing the work.

Significant factors for site selection

If you have a choice, you should choose to install metal structures flat area, not subject to landslides and waterlogging. But in small personal plots Most often there is no choice - a carport is placed right behind the gate, a veranda near the house, a gazebo in the depths of the site. The area may need to be leveled and sometimes drained.

If there is a danger of soil layers sliding, or you live in an earthquake-prone area, the design of any structure above a dog kennel should be left to professionals to ensure your safety.

How to calculate the load

Snow load per 1 m² of roof is calculated according to SP 20.13330.2017 “Loads and impacts. Updated version of SNiP 2.01.07-85" depending on the region. When calculating, it is not the roof area that is taken, but the area of the roof projection onto the horizontal. The weight of the sheathing and roofing is calculated in the same way. According to the drawing, the weight of one truss is calculated and multiplied by their number.

The load on one truss is calculated by dividing the sum of the total load on the roof of snow, the weight of the sheathing and covering, the weight of the structures themselves, by the number of trusses.

Entrance door and canopy

Visors over front door They are small in size and cantilevered.

The width of the canopy should be equal to the width of the porch + 300 mm on each side. The depth of the canopy should cover the steps. The length of the canopy is equal to the sum of the length of the platform and steps. The length of the upper platform should be one and a half times wider than the door, that is, 0.9 × 1.5 = 1.35 m. Plus 250 mm for each step.

For example:

for a porch with two steps and a width of 1200 mm, the dimensions of the covered area (horizontal projection of the canopy) are equal to:

length (visor depth) = 1.35 + 2×0.25 = 1.85 m;

width = 1.2 + 0.3×2 = 1.8 m.

Free calculation programs

On the site http://sopromatguru.ru/raschet-balki.php.
On the site http://rama.sopromat.org/2009/?gmini=off.

Calculation example

An example of calculating the truss of a free-standing carport for a middle-class car (D):

The width of the car is 1.73 m, length 4.6 m.

Minimum truss width between supports:

1.73 + 1 = 2.73 m, for ease of opening doors we take a width of 3.5 m.

Truss width including roof overhangs:

3.5 + 2×0.3 = 4.1 m.

Canopy length:

4.6 + 1 = 5.6 m, take a length of 6 m.

With this length it is possible to install supports every 2 m or less. To lighten the load-bearing structures, we take the distance between the supports to be 1.5 m.

We adopt a triangular gable roof shape - it is the easiest to manufacture and at the same time economical in terms of material consumption. We take the roof inclination angle to be 30° - at this inclination angle, snow and fallen leaves will not linger on the roof.

The height of the truss in the center (central post) will be equal to:

Total: the length of the lower chord of the truss is 4.1 m; the upper belt - two halves of 2.355 m each, total length 4.71 m, the stand in the center has a height of 1.16 m.

For such short trusses it is quite enough to use square pipe 40×40 mm with a wall thickness of 3 mm.

The main stages of work on the manufacture and installation of trusses with your own hands

Before installing the trusses, work is carried out on site planning, installation of supports, concreting of support foundations, welding of side braces or side trusses. Then the transverse trusses are installed.

The procedure for performing work on the manufacture and installation of trusses:

Trusses are welded on a flat surface.
The trusses are treated with an anti-corrosion primer and painted twice. Do not paint areas where trusses are welded to supports. This work can be done after the trusses are installed, but painting at height is inconvenient.
They lift the trusses, install them on supports, check the angles and horizontality, and weld them to the supports. This work is performed by a team of several people.
Paint over the welding areas.
The sheathing is installed and the roofing is laid.

How to weld trusses

The trusses are assembled on a level area. Before assembly, the workpieces are cut, cleaned of rust, and burrs on the cuts are sanded off. The truss elements are fastened with clamps, the dimensions, angles, and flatness are checked. Weld the structure on one side, let it cool, and turn it over to the other side. Remove the clamps and boil the other side. Then the bead on the seam is sanded off. You can see the features of welding trusses in our video:

If you have limited skills as a welder and installer, you can order the manufacture of a truss from a specialized organization or team.

Conclusion

Construction of a canopy and installation of trusses is complex, skilled work. Small canopies and gazebos can be made independently with the help of family members.

It is better to entrust the installation of large metal structures to a team of professionals. But professionals also need supervision. We say goodbye to our dear reader and hope that our article will help you understand the types of trusses, the choice of design, material and the procedure for constructing canopies and gazebos on your site. Subscribe to our website newsletter, bring friends, share interesting information with interlocutors on social networks.

Roof trusses for house construction are made mainly of wood, which is exposed to environment. In places where wood comes into contact with other materials, it is necessary to install gaskets that will serve as moisture insulation on the roof side and vapor barrier on the residential side. It is necessary to install ventilated gaps and treat them with fire retardants and antiseptics.

The roof truss carries all the structural loads of the roof, the weight of the roof, sheathing and resists external influences.

Roof truss made of metal structures is the most durable, reliable and quality material, which is suitable for absolutely all types of buildings, have a wide range of operation in various climatic zones and weather conditions.

The MSL Consulting Group company offers you roofing trusses made of metal structures of the following types:

Gable roof truss

A rafter system made of metal, based on a triangle, is the most rigid and maximum economical design, capable of evenly distributing loads across load-bearing walls home and become a load-bearing roofing part. It is created on the basis of accurate calculations based on the requirements for roof construction. There are a number structural elements, variations, the use of which affect the variety of types of structures of such trusses. There is a difference in the intersupport spans - hanging rafters rest on the outer supports, while inclined rafters have additional support on the middle load-bearing wall.

Roofing truss scissors

Original truss structure made of metal, where the lower plane consists of two segments (puffs) having a slope. The lower chord 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 advantages. 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 prefabricated tightening is no more than 2/3 of the angle of the rafters.

Single pitch roof truss

Used for arrangement pitched roof or for a zone-like one, where several slopes are mounted at different levels. The desired location of the lower part is on the leeward side. As a rule, the angle of inclination is lower than that of multi-slope roofs. When the length of the rafter leg is more than 4.5 m, supports (stands, struts) are required.

Beam roof truss with parallel chords

They are used on flat or slightly sloping single-pitched roofs, for arranging soft roofs, for attic and interfloor ceilings, or to strengthen them. The triangle system lattice makes the truss unchangeable under any load. Suitable for ceilings and large spans, which makes it most popular in the field of industrial construction.

Triangular frame roof truss with rectangular outline

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

Straight Post Attic Roof Truss

They are used in the construction of a gable roof to equip part of the under-roof space as a living space, creating additional space if necessary. The structure has two parallel beams and horizontal braces that form the geometry of the living space. The strut system is made outside it.

Roofing truss scissors. Type T

A scissor-shaped truss, the middle segment of the lower plane of which has no slope and is made horizontally. The central post under the ridge girder transfers horizontal stress to the lower chord of the truss, reducing it to zero. Additional racks allow you to increase the width of the purlin, the struts form the same angles - the basis of a reliable structure and distribute the remaining load. The rafters have two outer supports.

Attic roof truss with straight posts

Design with broken slopes for those cases when it is impossible to fit attic room into a simple triangular roof. When installed on a single-bay house, it is necessary to strengthen the contractions of the risers of the lower and upper chords (which serves as an interfloor ceiling). If there is additional support from the internal wall, this is not necessary. The living space here is formed by parallel contractions and racks. The truss has no central support and this gives room for an open loft layout.

Attic truss with a high tightening position and does not form a ceiling

The broken slopes form two angles of inclination - gentle and steep, which is ideal for arranging a spacious attic. There is no “dead” zone. Design feature trusses are overhanging rafters, due to which the trusses rest through corner struts on longitudinal walls with a fixed Mauerlat. The complex truss system at the top of the posts and struts that form the triangles requires precise calculation of the stress and load distribution. The high position of the tightening connecting the rafter legs places high demands on the fastenings and on the power of the tightening itself, since it reduces the bursting force of the metal rafters.

Types of metal trusses

Universal roofing trusses for industrial buildings: single-pitched and double-pitched. The spans for them are unified, they are taken as multiples of 3 m, and can be 18, 24, 30 meters. The angle of inclination of the braces is usually 45-50°, general shape provides structural rigidity and the ability to withstand heavy loads.
Metal roof trusses with additional trusses are used in non-girder 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%.
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 shape of the belts, spans, sizes, and manufacturing patterns. Thus, static trusses can be frame, beam, cable-stayed, arched. Beams in this case are distinguished by more economical consumption of materials, lighter weight than others, they can be used for the manufacture of structures that require resistance to large, constant loads. Arched roofs are used to create unusual, attractive roof shapes, but their construction requires building materials somewhat enlarged.

In addition, combined patterns are used, polygonal, segmented, triangular, trapezoidal, with parallel belts. All of them are distinguished by great strength, low weight, and stability. High quality installation of the rafter system is ensured by the fact that any calculation for such a structure is carried out using special programs.

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

Roof truss installation

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

Installation is carried out in several stages:

Installation of the top beam braces on the ground (geometrically aligned with the purlin lines). Connections are made using self-tapping screws.
Fixing the first truss in a given position with a ground brace.
Installation of all subsequent trusses in a similar way.
Installation of braces and lintels on beams.
Fastening linear connections between beams and braces.

In various branches of construction, trusses made of profile pipes are often used. Such trusses are structurally metal structures consisting of individual rods and having a lattice shape. From designs from solid beams farms are less expensive and more labor intensive. To connect profile pipes, both the welding method and rivets can be used.

Metal profile trusses are suitable for creating any spans, regardless of their length - but for this to be possible, the structure must be calculated with extreme accuracy before assembly. If the calculation of the metal truss was correct, and all the work on assembling the metal structures was carried out correctly, then the finished truss will only need to be lifted and installed on the prepared harness.

Advantages of using metal rafters

Trusses made from profile pipes have many advantages, including:

Low weight of the structure;
Long service life;
Excellent strength properties;
Ability to create structures of complex configuration;
Reasonable cost of metal elements.

Classification of profile pipe trusses

All metal constructions farms have several common parameters, which ensure the division of farms into types.

These options include:

Number of belts. Metal trusses can have only one belt, and then the entire structure will lie in one plane, or two belts. In the latter case, the truss will be called a hanging truss. The design of a hanging truss includes two chords - upper and lower.
Form. There is an arched truss, straight, single-slope and double-slope.
Circuit.
Tilt angle.

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

Parallel belt trusses. Such structures are most often used as a support for arranging a roof made of soft roofing materials. A truss with a parallel belt is created from identical parts with identical dimensions.
Lean farms. Single slope designs are inexpensive because they require few materials to make. The finished structure is quite durable, which is ensured by the rigidity of the nodes.
Polygonal trusses. These structures have very good load-bearing capacity, but you have to pay for it - polygonal metal structures are very inconvenient to install.
Triangular trusses. As a rule, trusses with a triangular contour are used to install roofs located at a large slope. Among the disadvantages of such farms, it is worth noting the large number of unnecessary costs associated with the mass of waste during production.

How to calculate the angle of inclination

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

22-30 degrees. In this case, the ratio of the length and height of the finished structure is 5:1. Trusses with such a slope, being light in weight, are excellent for arranging short spans in private construction. As a rule, trusses with such a slope have a triangular outline.
15-22 degrees. In a design with such a slope, the length exceeds the height by seven times. Trusses of this type cannot be more than 20 m in length. If it is necessary to increase the height of the finished structure, the lower chord is given a broken shape.
15 or less. The best option in this case, there will be metal rafters from a profile pipe, connected in the shape of a trapezoid - short racks will reduce the impact of longitudinal bending on the structure.

In the case of spans whose length exceeds 14 m, it is necessary to use braces. The upper belt must be equipped with a panel about 150-250 cm long. When even number panels will result in a structure consisting of two belts. For spans longer than 20 m, the metal structure must be reinforced with additional supporting elements connected by support columns.

If you need to reduce the weight of the finished metal structure, you should pay attention to the Polonceau truss. It includes two triangular-shaped systems that are connected by tightening. Using this scheme, you can do without large-sized braces in the middle panels.

When creating trusses with a slope of about 6-10 degrees for pitched roofs, you need to remember that the finished structure should not be symmetrical in shape.

Calculation of a metal truss

When making calculations, it is necessary to take into account all the requirements for metal structures state standards. To create the most efficient and reliable design, it is necessary to prepare a high-quality drawing at the design stage, which will display all the elements of the truss, their dimensions and features of connection with the supporting structure.

Before you calculate a farm for a canopy, you should decide on the requirements for the finished farm, and then start from savings, avoiding unnecessary costs. The height of the truss is determined by the type of floor, the total weight of the structure and the possibility of its further displacement. The length of the metal structure depends on the expected slope (for structures longer than 36 m, a construction lift calculation will also be required).

The panels must be selected in such a way that they can withstand the loads that will be placed on the farm. Braces may have different sizes corners, so when choosing panels you need to take this parameter into account. In the case of triangular grilles, the angle is 45 degrees, and in the case of slanted grilles, it is 35 degrees.

The calculation of a roof from a profile pipe ends with determining the distance at which the nodes will be created relative to each other. As a rule, this indicator is equal to the width of the selected panels. The optimal pitch for the supports of the entire structure is 1.7 m.

When calculating a single-pitch truss, you need to understand that as the height of the structure increases, its load bearing capacity. In addition, if necessary, it is worth supplementing the truss diagram with several stiffening ribs that can strengthen the structure.

Calculation examples

When selecting pipes for metal trusses, you should consider the following recommendations:

For arranging structures less than 4.5 m wide, pipes with a cross section of 40x20 mm and a wall thickness of 2 mm are suitable;
For a structure width of 4.5 to 5.5 m, 40 mm square profile pipes with a 2 mm wall are suitable;
For metal structures bigger size the same pipes as in the previous case, but with a 3 mm wall, or pipes with a cross section of 60x30 mm with a 2 mm wall are suitable.

The last parameter that should also be paid attention to when calculating is the cost of materials. First, you need to consider the cost of the pipes (remembering that the price of pipes is determined by their weight, not their length). Secondly, it’s worth asking about the cost complex works for the production of metal structures.

Recommendations for choosing pipes and manufacturing metal structures

Before cooking farms and picking optimal materials for future design, it is worth familiarizing yourself with the following recommendations:

When studying the range of pipes available on the market, you should give preference to rectangular or square products - the presence of stiffeners significantly increases their strength;
When selecting pipes for a rafter system, it would be best to opt for stainless steel products made of high-quality steel (pipe sizes are determined by the project);
When installing the main elements of the truss, tacks and double corners are used;
In the upper chords, I-angles with different sides, the smaller of which is necessary for docking;
For mounting the lower belt, corners with equal sides are quite suitable;
The main elements of large-sized structures are attached to each other with overhead plates;
The braces are mounted at an angle of 45 degrees, and the racks are mounted at a 90-degree angle.
When a metal truss for a canopy is welded, it is worth making sure that each weld is sufficiently reliable (read also: " ");
After welding work, the metal elements of the structure remain to be coated protective compounds and paint.

Conclusion

Trusses made from profile pipes are quite versatile and suitable for solving a wide range of problems. Making trusses cannot be called simple, but if you approach all stages of work with full responsibility, the result will be a reliable and high-quality structure.