Shed roof truss 6 meters. Farm for a shed roof from a profile pipe. Installation of a roof truss system

Today, profile pipe trusses are considered to be the ideal solution for building a garage, a residential building and outbuildings. Robust and durable, these designs are inexpensive, quick to build, and anyone with a modicum of math and cutting and welding skills can handle them. And how to choose the right profile, calculate the farm, make jumpers in it and install, we will now tell you in detail. To do this, we have prepared for you detailed workshops for making such farms, video tutorials and valuable tips from our experts!

Stage I. We design the farm and its elements

So what is a farm? This is a structure that ties the supports together into one single whole. In other words, the farm belongs to simple architectural structures, among the valuable advantages of which we highlight the following: high strength, excellent performance, low cost and good resistance to deformations and external loads.

Due to the fact that such trusses have a high bearing capacity, they are placed under any roofing materials, regardless of their weight.

The use in the construction of metal trusses from new or rectangular closed profiles is considered one of the most rational and constructive solutions. And for good reason:

The main secret is in savings due to the rational shape of the profile and the connection of all elements of the lattice.
Another valuable advantage of profile pipes for use in their manufacture of trusses is equal stability in two planes, excellent streamlining and ease of use.
With all their low weight, such trusses can withstand serious loads!

Roof trusses differ in the shape of the belts, the type of section of the rods and the types of lattice. And with the right approach, you can independently weld and install a truss from a profile pipe of any complexity! Even this one:

Stage II. We acquire a quality profile

So, before drafting future farms, you first need to decide on such important points:

contours, size and shape of the future roof;
material for the manufacture of the upper and lower chords of the truss, as well as its lattice;

Remember one simple thing: the profile pipe frame has so-called balance points, which are important to determine for the stability of the entire truss. And it is very important to choose high-quality material for this load:

Farms are built from a profile pipe of such types of sections: rectangular or square. These are available in different section sizes and diameters, with different wall thicknesses:

We recommend those that are specially sold for small buildings: these go up to 4.5 meters long and have a section of 40x20x2 mm.
If you will make farms longer than 5 meters, then choose a profile with parameters 40x40x2 mm.
For a full-scale construction of the roof of a residential building, you will need profile pipes with the following parameters: 40x60x3 mm.

The stability of the entire structure is directly proportional to the thickness of the profile, so do not use pipes for the manufacture of trusses, which are intended only for welding racks and frames - here are other characteristics. Also pay attention to which method the product was manufactured: by electric welding, hot-formed or cold-formed.

If you undertake to make such trusses on your own, then take square-section blanks - it is easiest to work with them. Get a square profile 3-5 mm thick, which will be strong enough and close in its characteristics to metal bars. But if you will make a farm just for a visor, then you can give preference to a more budget option.

Be sure to consider snow and wind loads in your area when designing. After all, when choosing a profile (in terms of the load on it), the angle of inclination of the trusses is of great importance:

You can more accurately design a truss from a profile pipe using online calculators.

We only note that the simplest design of a profile pipe truss consists of several vertical posts and horizontal levels on which roof rafters can be attached. You can buy such a frame ready-made on your own, even on order in any city in Russia.

Stage III. We calculate the internal stress of the trusses

The most important and responsible task is to correctly calculate the truss from the profile pipe and select the desired format of the internal lattice. To do this, we need a calculator or other software similar to it, as well as some tabular data of SNiPs, which for this:

SNiP 2.01.07-85 (impacts, loads).
SNiP p-23-81 (data on steel structures).

Please review these documents if possible.

Roof shape and slope

The farm is needed for which specific roof? Shed, gable, domed, arched or hipped? The easiest option, of course, is the manufacture of a standard shed canopy. But you can also calculate and manufacture quite complex farms yourself:

A standard truss consists of such important elements as the upper and lower chords, racks, braces and auxiliary struts, which are also called sprengels. Inside the trusses there is a grid system; welds, rivets, special paired materials and scarves are used to connect pipes.

And, if you are going to make a roof with a complex shape, then such trusses will be an ideal option for it. It is very convenient to make them according to a template right on the ground, and only then lift them up.

Most often, in the construction of a small country house, garage or change house, the so-called Polonso trusses are used - a special design of triangular trusses connected by puffs, and the lower belt here comes out raised.

In fact, in this case, in order to increase the height of the structure, the lower chord is made broken, and then it is 0.23 of the flight length. For the interior space of the room is very convenient.

So, in total there are three main options for making a truss, depending on the slope of the roof:

from 6 to 15°;
from 15 to 20°;
from 22 to 35°.

What is the difference you ask? For example, if the angle of the structure is small, only up to 15 °, then it is rational to make the trusses in a trapezoidal shape. And at the same time, it is quite possible to reduce the weight of the structure itself, taking in height from 1/7 to 1/9 of the total flight length.

Those. follow this rule: the lower the weight, the greater the height of the truss. But if we already have a complex geometric shape, then you need to choose a different type of truss and gratings.

Types of trusses and roof shapes

Here is an example of specific trusses for each type of roof (single, double, complex):

Let's look at the types of farms:

triangular trusses are a classic for making the base for steep roof slopes or sheds. The cross section of pipes for such farms must be selected taking into account the weight of the roofing materials, as well as the operation of the building itself. Triangular trusses are good because they have simple shapes, are easy to calculate and execute. They are valued for under-roofing providing natural light. But we also note the disadvantages: these are additional profiles and long rods in the central segments of the lattice. And also here you will have to face some difficulties when welding sharp reference corners.
The next view is polygonal farms from a profile pipe. They are indispensable for the construction of large areas. Their welding is already of a more complex shape, and therefore they are not designed for lightweight structures. But such trusses are distinguished by greater metal savings and strength, which is especially good for hangars with large spans.
It is also considered strong truss with parallel belts. Such a farm differs from others in that it has all the details - repeating, with the same length of rods, belts and gratings. That is, there are a minimum of joints, and therefore it is easiest to calculate and cook one from a profile pipe.
A separate species is single slope trapezoidal truss supported by columns. Such a farm is ideal when a rigid fixation of the structure is necessary. She has slopes (braces) on the sides and there are no long rods of the upper crate. Suitable for roofs where reliability is especially important.

Here is an example of making trusses from a profile pipe as a universal option that is suitable for any garden buildings. We are talking about triangular farms, and you have probably already seen them many times:

A triangular truss with a crossbar is also quite simple, and is quite suitable for building gazebos and change houses:

And here arched farms are already much more difficult to manufacture, although they have a number of valuable advantages:

Your main task is to center the metal truss elements from the center of gravity in all directions, in simple terms, to minimize the load and correctly distribute it.

Therefore, choose the type of farm that is more suitable for this purpose. In addition to those listed above, a scissor truss, asymmetric, U-shaped, two-hinged, a truss with parallel belts and an attic truss with and without supports are also popular. As well as the attic view of the farm:

You will be interested to know that a certain design of the internal lattices of trusses is selected not at all for aesthetic reasons, but for quite practical ones: for the shape of the roof, the geometry of the ceiling and the calculation of loads.

You need to design your farm in such a way that all forces are concentrated specifically in the nodes. Then there will be no bending moments in the belts, braces and trusses - they will only work in compression and tension. And then the cross section of such elements is reduced to the required minimum, while significantly saving on the material. And the farm itself, to everything, you can easily make articulated.

Otherwise, the force distributed over the rods will constantly act on the truss, and a bending moment will appear, in addition to the total stress. And here then it is important to correctly calculate the maximum bending values for each individual rod.

Then the cross section of such rods should be larger than if the truss itself was loaded with point forces. To summarize: trusses, on which the distributed load acts evenly, are made of short elements with hinged nodes.

Let's see what is the advantage of one or another type of lattice in terms of load distribution:

triangular Lattice systems are always used in trusses with parallel chords and trapezoidal truss. Its main advantage is that it gives the smallest total grating length.
Diagonal the system is good at low truss heights. But the consumption of material for it is considerable, because here the entire path of effort goes through the nodes and rods of the lattice. And therefore, when designing, it is important to lay a maximum of rods so that the long elements are stretched and the racks are compressed.
Another view - trussed lattice. It is made in case of loads of the upper belt, as well as when it is necessary to reduce the length of the lattice itself. Here, the advantage is to maintain the optimal distance between the elements of all transverse structures, which, in turn, allows you to maintain a normal distance between the runs, which will be a practical moment for the installation of roof elements. But creating such a lattice with your own hands is a rather laborious task with additional metal costs.
cruciform the lattice allows you to distribute the load on the farm in both directions at once.
Another type of grid cross where the braces are attached directly to the truss wall.
And finally semi-diagonal and rhombic lattices, the most rigid of the listed. Here two systems of braces interact at once.

We have prepared an illustration for you, where we have collected all types of trusses and their lattices together:

Here is an example of how a triangular lattice truss is made:

Making a truss with a diagonal lattice looks like this:

This is not to say that one of the types of trusses is definitely better or worse than the other - each of them is valuable for less material consumption, lighter weight, bearing capacity and fastening method. The figure is responsible for which load scheme will act on it. And the weight of the farm, the appearance and the complexity of its manufacture will directly depend on the type of lattice chosen.

We also note such an unusual version of the manufacture of a farm, when it itself becomes a part or support for another, wooden one:

Stage IV. We manufacture and install farms

We will give you some valuable tips on how to weld such farms on your own without much difficulty right on your site:

Option one: you can contact the factory, and they will make to order all the necessary individual elements according to your drawing, which you will only have to weld on the spot.
The second option: purchase a ready-made profile. Then you will only have to sheathe the trusses from the inside with boards or plywood, and in between lay insulation if necessary. But this method will cost, of course, more expensive.

Here, for example, is a good video tutorial on how to lengthen a pipe by welding and achieve the perfect geometry:

Here is also a very helpful video on how to cut a pipe at a 45° angle:

So, now we come directly to the assembly of the farms themselves. The following step-by-step instructions will help you deal with this:

Step 1: Prepare the trusses first. It is better to weld them in advance directly on the ground.
Step 2. Install vertical supports for future farms. It is imperative that they are truly vertical, so test them with a plumb line.
Step 3. Now take the longitudinal pipes and weld them to the support posts.
Step 4 Raise the trusses and weld them to the longitudinal pipes. After that, it is important to clean all junctions.
Step 5. Paint the finished frame with special paint, having previously cleaned and degreased it. In this case, pay special attention to the junctions of the profile pipes.

What else do those who make such farms at home face? First, consider in advance the support tables on which you will lay the truss. It is far from the best option to throw it on the ground - it will be very inconvenient to work.

Therefore, it is better to put small support bridges that will be slightly wider than the lower and upper chords of the truss. After all, you will manually measure and insert jumpers between the belts, and it is important that they do not fall to the ground.

Also, in some designs, you have to combine different types of trusses in order to attach the roof to the wall of the building:

Also keep in mind that you will need to cut farms a lot, for all elements, and therefore we advise you to either purchase or build a home-made machine like the one in our master class. Here is how it works:

In this way, step by step, you will draw up a drawing, calculate the truss lattice, make blanks and weld the structure already in place. Moreover, you will also have the remains of profile pipes in your consumption, therefore, you will not need to throw anything away - all this will be needed for the secondary parts of the canopy or hangar!

Stage V. We clean and paint finished trusses

After you install the trusses in their permanent place, be sure to treat them with anti-corrosion compounds and paint with polymer paints. Ideal for this purpose paint, which is durable and resistant to ultraviolet radiation:

That's all, the profile pipe farm is ready! All that remains is the finishing work on sheathing the trusses from the inside with finishing and from the outside with roofing material:

Believe me, making a metal truss from a profile pipe is really not difficult for you. A well-designed drawing, high-quality welding of a truss from a profile pipe and the desire to do everything correctly and accurately play a huge role.

Truss structures from a profile pipe
Canopy calculation
Recommendations for the correct selection and manufacture of tubular metal structures

When the construction area is large enough, the issue of ensuring the reliability and strength of the structure is of particular importance. There is a need to strengthen the rafter system, the rafters of which could cover rather long spans.
Farms from a profile pipe are metal structures assembled using lattice rods. The manufacture of metal trusses is a more labor-intensive process than in the case of solid beams, but more economical. In production, paired material is used, and scarves are used as a connecting part. The entire structure is assembled using welding or riveting.

With their help, it is possible to block spans of any length, however, it is worth noting that a competent calculation is required for proper installation. Then, under the condition of high-quality welding, it remains only in the future to transfer the pipe assemblies to the top and mount them along the upper trim, according to the markings.

Bearing farms from a profile pipe have many undeniable advantages:

minimum weight;
they are durable;
hardy;
the nodes are very strong, therefore they are able to withstand high loads;
with their help, you can build structures with complex geometry;
allow you to save money, since the prices for the manufacture of metal structures from a profile pipe are quite acceptable for solving a wide range of tasks.

The division of these structures into specific types is based on different parameters. Let's start with the main -

The number of belts.

Distinguish:

supports, the components of which are located in a single plane;
hanging, they include two belts, according to their location they are called, respectively, lower, upper.

The first parameter is:

arched trusses from a profile pipe,
are also straight ;
single-sided or double-sided.

In accordance with the contour, there are:

having a parallel belt. This is the best option for arranging a soft roof. Such a support is assembled very simply, since its components are identical parts and, importantly, the dimensions of the lattice coincide with the dimensions of the rods for the belt;

lean-to. Differ in rigid knots which allow to perceive considerable external loadings. Their construction takes a small amount of material, so these designs are quite economical;
polygonal. Although they are able to withstand a lot of weight, however, their installation is laborious and rather complicated;
triangular. They are practically indispensable when constructing roofs with a large angle of inclination. Their only disadvantage is a large amount of waste during construction.

Tilt angle. Typical trusses from a profile pipe are divided into three groups:

22°- 30°. The height and length of the metal structure in this case are related as one to five. This is the best option for covering small spans in domestic construction. Their main advantage is their low weight. Most of all, triangular ones are suitable for such an analogue.

For spans having a length of more than 14 m, braces are used, which are installed from top to bottom. A panel is placed along the upper belt (about 150 - 250 cm in length). Thus, with these initial data, we have a design that includes two belts. The number of panels is even.

If the span exceeds 20 m, then there is a need for a sub-rafter metal structure connected by supporting columns.

A special mention is the so-called Polonso farm. It consists of two triangular systems connected to one another through a puff. This design solution avoids the installation of long braces in the middle panels, which leads to a significant reduction in overall weight.

15°-22°. The ratio of height and length in this case is one to seven. The maximum allowable length for such a frame is 20 m. If, according to the operating conditions, it is necessary to increase its height, then the lower belt is broken.
less than 15°. In such projects, it is recommended to use trapezoidal metal rafters. The presence of short struts in them contributes to an increase in resistance to buckling.

Attention!

Farms from a profile pipe for a shed roof with a slope angle of 6–10 ° should have an asymmetric shape.

Heights are determined by dividing the span length into seven, eight or nine parts, taking as a basis the features of a given design.

Canopy calculation

Calculations are based on the requirements of SNiP:

A mandatory component of any calculation and subsequent installation of the structure is a drawing.

A diagram is being prepared indicating the relationship between the length of the metal structure and the slope of the roof.

It also takes into account the outlines of the support belts. The contour of the belt is determined by the purpose of the structure, the type of roofing and the angle of inclination.
When choosing sizes, as a rule, they follow the principle of economy, unless, of course, CTs require otherwise. The height of the structure is determined by the type of floor, the minimum total weight, the possibility of movement, while the length is determined by the established slope.

With a truss length of more than 36 m, a construction lift is additionally calculated.

The dimensions of the panels are calculated taking into account the loads perceived by the structure. At the same time, it should be remembered that the angles of the braces for different metal rafters are different, but the panel must correspond to them. For a triangular lattice, the desired angle is 45°, for an oblique one - 35°.
Completes the calculation by determining the gap between nodes. It usually corresponds to the width of the panel.

Calculations are performed taking into account the fact that an increase in height leads to an increase in the bearing capacity. On such a canopy, the snow cover will not linger. One of the ways to strengthen trusses from a profile pipe is to install several strong stiffeners.

To determine the dimensions of the metal structure for canopies, follow the following data:

for structures with a width of not more than 4.5 m, use products measuring 40 by 20 by 2 mm;
less than 5.5 m - 40 by 40 by 2 mm;
over 5.5 m, products with a size of 40 by 40 by 3 mm or 60 by 30 by 2 mm will be optimal.

When calculating the step, it is necessary to take into account that the greatest possible distance from one canopy support to another is 1.7 m. If this limitation is violated, the strength and reliability of the structure will be in question.

When the necessary parameters are fully obtained, with the help of formulas and special programs, an appropriate design scheme is obtained. Now it remains to think about how to weld the farm correctly.

On a note

The calculations should take into account:

purchase price of one ton of metal;
prices for the manufacture of metal structures from a profile pipe (or you can sum up the costs for welding, anti-corrosion treatment, installation, taken separately).

Recommendations for the correct selection and manufacture of tubular metal structures

When choosing a standard size, it is advisable to opt for rectangular or square products, since the existing two stiffeners will provide the finished metal structure with the greatest stability.
Use only high-quality products made of high-carbon alloy steel, which does not corrode and is resistant to aggressive environmental influences. The wall thickness and diameter are selected in accordance with those laid down in the project. Thus, the required bearing capacity of the metal rafters will be ensured.
To connect the main components of the farm to each other, tacks and paired corners are used.
In the upper belt, for closing the frame, versatile I-beams are needed, and the docking is performed on the smaller side.
To pair the parts of the lower belt, equilateral corners are used.
The main parts of long structures are connected by overhead plates.

The braces are set at 45 degrees, and the racks are set at right angles. Having completed the assembly of the main structure, they proceed to welding the truss from the profile pipe. Each of the welds must be checked for quality, since they determine the reliability of the future structure. After welding is completed, metal rafters are treated with special anti-corrosion compounds and coated with paint.

Making metal trusses for a canopy on video.

A canopy made of pipes and polycarbonate is becoming an increasingly popular architectural form in the backyard. No wonder, because this building can perform many functions, ranging from an open garage for a car, a wood warehouse, an indoor playground, and ending with a recreation area with a barbecue and easy chairs.

The key advantage is the ability to make such a design with your own hands. In the presented article, recommendations will be given on the choice of material, examples of calculations of supports and trusses, and how to weld a canopy from a profile pipe.

Calculation of the optimal shape of the canopy

The length of the rafter depends on the angle of the truss. For different angles, it is optimal to use different roofing materials:

22-30 - the optimal angle of inclination for buildings in areas with significant snow loads. As a design of a canopy from a profile pipe with such an angle, it provides a predominantly triangular shape. It is optimal for asbestos straight and corrugated sheets, various types of metal profiles and eternite roofing.
15-22 - are also gable with metal types of roofing. This angle of inclination is typical for regions with increased wind loads. The maximum span of a triangular truss with such an angle is 20 m.
6-15 - mainly single-pitched trapezoidal trusses with a polycarbonate coating and corrugated board.

Shed canopy from a profile pipe, photo of a building with a corrugated roof

The calculation of a polycarbonate canopy from a profile pipe is carried out in accordance with SNiP P-23-81 "Steel structures" and SNiP 2.01.07-85 "Loads and impacts".

Technological requirements for the farm and the calculation sequence is as follows. In accordance with the terms of reference, the required span is determined. According to the presented scheme, we substitute the dimensions of the span and determine the height of the structure. The angle of inclination of the truss and the optimal shape of the roof of the canopy are set. Accordingly, the contours of the upper and lower chords of the truss, the general outlines and the type of roofing are determined.

Important! The maximum distance at which trusses are placed in the manufacture of a canopy from a profile pipe is 1.75 m.

Scheme of the dependence of the length of the rafters on the angle of the roof when calculating a truss from a profile pipe for a canopy

Profile selection

As a material for assembling a truss truss, you can use channels, tees, corners and other profiled rolled products that are made of steel grade St3SP or 09G2S (in accordance with GOST). However, all these materials have a significant drawback compared to profiled pipes - they are much heavier and thicker with comparable strength characteristics.

The dimensions of the frame elements for a canopy from a profile pipe depend on the dimensions of the building. In accordance with GOST 23119-78 and GOST 23118-99, the following materials are used to create a canopy from a square pipe with your own hands:

For compact buildings with a span width of up to 4.5 m - 40x20x2 mm;
Structures of medium size with a span of up to 5.5 m are made of a professional pipe 40x40x2mm;
Buildings of considerable size with spans of more than 5.5 m are mounted from profile pipes of various sections 40x40x3 mm or 60x30x2mm.
The size of the rack for a canopy from a professional pipe is 80 80 by 3 mm.

Drawings, dimensions and main connections

Before proceeding with the assembly of a canopy from a profile pipe with your own hands, it is necessary to draw a detailed plan of the entire structure, indicating the exact dimensions of all elements. This will help calculate the exact amount of materials of each type and calculate the cost of construction.

Drawing of a canopy from a profile pipe indicating the main overall dimensions

In addition, it is desirable to make an additional drawing of the most complex structures. In this case, this is a shed truss and the attachment points of its main elements.

Scheme for the manufacture of a truss from a profile pipe for a canopy with the main fasteners

One of the main advantages of a profile pipe is the possibility of a beadless connection. This is manifested in the simplicity of design and low cost of the truss with a rafter span of up to 30 m. At the same time, the roofing material can rest directly on the upper chord of the truss, provided it is sufficiently rigid.

Mounting points for assembling a canopy from a profile pipe with your own hands, in the photo a - a triangular lattice, b - support, c - diagonal lattice

The advantages of a bevelled welded joint are:

A significant reduction in the weight of the truss, compared with riveted or bolted structures, up to 20% and 25%, respectively.
Reducing labor costs and manufacturing costs, both for single items and for small-scale production.
Low cost of welding and the ability to automate the process by using machines with a continuous wire feeder.
Equal strength of the weld and the products to be joined.

Among the shortcomings can be noted:

The need to have rather expensive equipment;
Welding experience required.

Bolted connections in the manufacture of products from a profile pipe are quite common. Usually they are used in collapsible canopies from a profile pipe or in products manufactured for mass consumption.

Bolted connections are the easiest for mounting a canopy from a profile pipe with your own hands, photo of the attached frame element

The main advantages of such compounds are:

Ease of assembly;
No need for additional equipment;
Possibility of complete dismantling of the structure.

Disadvantages:

The weight of the structure increases;
Additional fasteners required;
The strength and reliability of bolted joints is somewhat lower than welded ones.

Summing up

The article examined the design and methods of manufacturing the simplest shed canopy from a profile pipe with your own hands, however, a profiled pipe is a rather “flexible” material from which complex and aesthetically attractive designs can be made.

A complex structure for creating a canopy from a professional pipe with your own hands, a photo of a shed, domed structure

Canopies on a metal frame make life easier. They will protect the car from the weather, cover the summer veranda, gazebo. They will replace the roof of the workshop or the canopy over the entrance. Turning to professionals, you will get any kind of canopy. But many will cope with the installation work themselves. True, you will need an accurate calculation of the farm from the profile pipe. You can not do without the appropriate equipment and materials. Of course, welding and cutting skills are also needed.

frame material

The basis of the canopies is steel, polymers, wood, aluminum, reinforced concrete. But, more often, the frame is made up of metal trusses from a profile pipe. This material is hollow, relatively light, but durable. In section it looks like:

rectangle;
square;
oval (as well as semi- and flat-oval figure);
polyhedron.

When welding from a truss profile pipe, a square or rectangular section is often chosen. These profiles are easier to process.

Variety of pipe profiles

Permissible loads depend on the wall thickness, metal grade, manufacturing method. The material is often high-quality structural steel (1-3ps/sp, 1-2ps(sp)). For special needs, low-alloy alloys and galvanizing are used.

The length of profile pipes usually ranges from 6 m for small sections to 12 m for large ones. Minimum parameters from 10×10×1 mm and 15×15×1.5 mm. With an increase in the wall thickness, the strength of the profiles increases. For example, on sections 50 × 50 × 1.5 mm, 100 × 100 × 3 mm and more. Products of maximum dimensions (300 × 300 × 12 mm or more) are more suitable for industrial buildings.

As for the parameters of the frame elements, there are the following recommendations:

for small-sized canopies (up to 4.5 m wide), pipe material with a section of 40 × 20 × 2 mm is used;
if the width is up to 5.5 m, parameters 40 × 40 × 2 mm are recommended;
for canopies of larger sizes, it is advised to take pipes 40 × 40 × 3 mm, 60 × 30 × 2 mm.

What is a farm

The farm is called the core system, the basis of the building structure. It consists of rectilinear elements connected at nodes. For example, we consider the design of a truss from a profile pipe, in which there is no misalignment of the rods and there are no off-nodal loads. Then only tensile and compressive forces will arise in its constituent parts. The mechanics of this system allows it to remain geometrically unchanged when replacing rigidly attached nodes with articulated ones.

An example of a welded rod system

The farm consists of the following elements:

upper belt;
lower belt;
stand perpendicular to the axis;
brace (or brace), inclined to the axis;
auxiliary support brace (sprengel).

Lattice system can be triangular, diagonal, semi-diagonal, cross. For connection, scarves, paired materials, rivets, welds are used.

Mounting options in knots

The manufacture of trusses from a profile pipe involves the assembly of a belt with certain outlines. By type they are:

segment;
polygonal;
gable (or trapezoidal);
with parallel belts;
triangular (d-i);
with a raised broken lower belt;
lean-to;
console.

Types according to the outlines of the belts

Some systems are easier to install, others are more economical in terms of material consumption, and others are easier in terms of supporting nodes.

Fundamentals of Farm Calculation

Influence of tilt angle

The choice of the design of canopy trusses from a profile pipe is associated with the slope of the designed structure. There are three possible options:

from 6° to 15°;
from 15° to 22°;
from 22° to 35°.

With a minimum angle (6°-15°), trapezoidal outlines of the belts are recommended. To reduce weight, a height of 1/7 or 1/9 of the total span length is allowed. When designing a sloping canopy of complex geometric shape, it is necessary to raise it in the middle part above the supports. Take advantage of the Polonso farms recommended by many experts. They are a system of two triangles connected by a puff. If you need a tall structure, it is better to choose a polygonal structure with a raised lower chord.

When the slope angle exceeds 20°, the height should be 1/7 of the total span length. The latter reaches 20 m. To increase the structure, the lower belt is made broken. Then the increase will be up to 0.23 span length. Tabular data is used to calculate the required parameters.

Table for determining the slope of the truss system

With a slope of more than 22 °, calculations are carried out according to special programs. Canopies of this kind are more often used for roofing made of slate, metal and similar materials. Here, triangular trusses from a profile pipe are used with their height of 1/5 of the entire length of the span.

The greater the angle of inclination, the less precipitation and heavy snow will accumulate on the canopy. The bearing capacity of the system increases with its height. Additional stiffening ribs are provided for additional strength.

Base Angle Options

To understand how to calculate a truss from a profile pipe, it is imperative to find out the parameters of the base nodes. For example, the dimensions of the span should usually be specified in the terms of reference. The number of panels, their dimensions are pre-assigned. Calculate the optimal height (H) in the middle of the span.

If the belts are parallel, polygonal, trapezoidal, H=1/8×L, where L is the length of the truss. The top belt should have a slope of about 1/8xL or 1/12xL.
For triangular type, on average, H=1/4×L or H=1/5×L.

Lattice braces should have a slope of approximately 45° (within 35°-50°).

Use a ready-made standard project, then you don’t have to do the calculation

In order for the canopy to be reliable and last for a long time, its project requires accurate calculations. After the calculation, materials are purchased, and then the frame is mounted. There is a more costly way - to purchase ready-made modules and assemble the structure on site. Another option is more difficult - to do the calculations yourself. Then you will need data from special reference books on SNiP 2.01.07-85 (impacts, loads), as well as SNiP P-23-81 (data on steel structures). You need to do the following.

Decide on the block diagram in accordance with the functions of the canopy, the angle of inclination, the material of the rods.
Select options. Take into account the relationship between the height and minimum weight of the roof, its material and type, slope.
Calculate the panel dimensions of the structure according to the distance of the individual parts responsible for the transfer of loads. The distance between adjacent nodes is determined, usually equal to the width of the panel. If the span is more than 36 m, the building lift is calculated - the reverse extinguishing bend, which acts due to the loads on the structure.

Among the methods for calculating statically determinate trusses, one of the simplest is cutting out nodes (areas where the rods are hinged). Other options are the Ritter method, the Henneberg rod replacement method. As well as a graphical solution by drawing up a Maxwell-Cremona diagram. In modern computer programs, the method of cutting nodes is more often used.

For a person who has knowledge of mechanics and strength of materials, it is not so difficult to calculate all this. The rest should take into account that the service life and safety of the canopy depend on the accuracy of the calculations and the magnitude of the errors. It might be better to contact the experts. Or choose an option from ready-made design solutions, where you can simply substitute your values. When it is clear what kind of truss truss is needed from a profile pipe, a drawing for it will surely be found on the Internet.

Significant Site Selection Factors

If the canopy belongs to a house or other building, it will require official permission, which will also have to be taken care of.

First, a site is selected where the structure will be located. What is taken into account?

Constant loads (fixed weight of lathing, roofing and other materials).
Variable loads (impact of climatic factors: wind, precipitation, including snow).
A special type of load (is there seismic activity in the region, storms, hurricanes, etc.).

Also important are the characteristics of the soil, the influence of nearby buildings. The designer must take into account all significant factors and clarifying coefficients that are included in the calculation algorithm. If you plan to do the calculations on your own, use 3D Max, Arkon, AutoCAD or similar programs. There is a calculation option in online versions of construction calculators. Be sure to find out for the intended project the recommended step between the bearing supports, the crate. As well as the parameters of materials and their quantity.

An example of a software calculation for a canopy covered with polycarbonate

Sequence of work

The assembly of the frame from metal profiles should be carried out only by a specialist in welding work. This responsible business requires knowledge and skillful handling of the tool. It is necessary not only to understand how to weld a truss from a profile pipe. It is important which nodes are more correct to assemble on the ground, and only then raise them to the supports. If the structure is heavy, equipment will be required for installation.

Usually the installation process takes place in the following sequence:

Area marking is in progress. Embedded parts, vertical supports are installed. Often, metal pipes are immediately placed in the pits, and then concreted. The verticality of the installation is checked by a plumb line. To control parallelism, a cord or thread is stretched between the extreme racks, the rest are set along the resulting line.
Longitudinal pipes are fixed to the supports by welding.
On the ground, nodes and elements of trusses are welded. With the help of braces and jumpers, the belts of the structure are connected. Then the blocks should be raised to the desired height. They are welded to the longitudinal pipes in the areas where the vertical supports are placed. Longitudinal lintels are welded between the trusses along the slope for further fastening of the roofing material. They make holes for fasteners.
All connecting areas are carefully cleaned. Especially the upper edges of the frame, where the roof will lie in the future. The surface of the profiles is cleaned, degreased, treated with a primer and painted.

Using the finished project, you will quickly start assembling the canopy

Experts advise to perform such responsible work only with relevant experience. It is not enough to know in theory how to properly weld a truss from a profile pipe. Having done something wrong, ignoring the nuances, the home master risks. The canopy will collapse and collapse. Everything that will be under it will suffer - cars or people. So take your knowledge to heart!

Video: how to weld a truss from a profile pipe

Determination of the internal forces of the truss

Often we do not have the opportunity to use a conventional beam for a particular structure, and we are forced to use a more complex structure called a truss.
although it differs from the calculation of the beam, it will not be difficult for us to calculate it. You will only need attention, basic knowledge of algebra and geometry, and an hour or two of free time.
So, let's begin. Before calculating the farm, let's ask ourselves some real situation that you might encounter. For example, you need to block a garage 6 meters wide and 9 meters long, but you don’t have floor slabs or beams. Only metal corners of various profiles. Here we will collect our farm from them!
Subsequently, girders and corrugated board will be based on the farm. The support of the truss on the walls of the garage is articulated.

To begin with, you will need to find out all the geometric dimensions and angles of your farm. Here we need our mathematics, namely geometry. We find the angles using the cosine theorem.

Then you need to collect all the loads on your farm (you can see in the article). Let's say you have the following loading option:

Next, we need to number all the elements, nodes of the farm and set the support reactions (the elements are signed in green, and the nodes in blue).

To find our reactions, we write the equations for the balance of forces on the y axis and the equation for the balance of moments with respect to node 2.

Ra+Rb-100-200-200-200-100=0;
200*1.5 +200*3+200*4.5+100*6-Rb*6=0;

From the second equation, we find the support reaction Rb:

Rb=(200*1.5 +200*3+200*4.5+100*6) / 6;
Rb=400 kg

Knowing that Rb=400 kg, from the 1st equation we find Ra:

Ra=100+200+200+200+100-Rb;
Ra=800-400=400 kg;

Once the support reactions are known, we must find the node with the fewest unknowns (each numbered element is an unknown). From this point on, we begin to divide the truss into separate nodes and find the internal forces of the truss rods in each of these nodes. It is on these internal forces that we will select the sections of our rods.

If it turned out that the forces in the rod are directed from the center, then our rod tends to stretch (return to its original position), which means that it itself is compressed. And if the efforts of the rod are directed towards the center, then the rod tends to shrink, that is, it is stretched.

So, let's move on to the calculation. There are only 2 unknown quantities in node 1, so let's consider this node (we set the directions of efforts S1 and S2 from our own considerations, in any case, we will get it right in the end).

Consider the equilibrium equations on the x and y axes.

S2 * sin82.41 = 0; - on the x-axis
-100 + S1 = 0; - on the y-axis

It can be seen from the 1st equation that S2=0, that is, the 2nd rod is not loaded!
It can be seen from the 2nd equation that S1=100 kg.

Since the value of S1 turned out to be positive, it means that we have chosen the direction of effort correctly! If it would turn out to be negative, then the direction should be changed and the sign should be changed to “+”.

Knowing the direction of the effort S1, we can imagine what the 1st rod is like.

Since one force was directed to the node (node 1), the second force will also be directed to the node (node 2). So our rod is trying to stretch, which means it is compressed.
Next, consider node 2. There were 3 unknowns in it, but since we have already found the value and direction of S1, only 2 unknowns remain.

Yet again

100 + 400 - sin33.69 * S3 = 0 - on the y-axis
- S3 * cos33.69 + S4 = 0 - on the x-axis

From the 1st equation S3 = 540.83 kg (rod #3 is compressed).
From the 2nd equation S4 = 450 kg (rod #4 is stretched).
Consider the 8th node:

Let's write equations on the x and y axes:

100 + S13 = 0 - on the y-axis
-S11 * cos7.59 = 0 - on the x-axis

From here:

S13 = 100 kg (rod #13 compressed)
S11 = 0 (zero rod, there is no effort in it)

Consider the 7th node:

Let's write equations on the x and y axes:

100 + 400 - S12 * sin21.8 = 0 - on the y-axis
S12 * cos21.8 - S10 = 0 - on the x-axis

FROM the 1st equation we find S12:

S12 = 807.82 kg (rod #12 compressed)

From the 2nd equation we find S10:

S10 = 750.05 kg (rod #10 stretched)

Let's take a look at node #3. As far as we remember, the 2nd rod is zero, which means we will not draw it.

Equations on the x and y axes:

200 + 540.83 * sin33.69 - S5 * cos56.31 + S6 * sin7.59 = 0 - to the y-axis
540.83 * cos33.69 - S6 * cos7.59 + S5 * sin56.31 = 0 - on the x-axis

And here we already need algebra. I will not describe in detail the methodology for finding unknown quantities, but the essence is this - from the 1st equation we express S5 and substitute it into the 2nd equation.
As a result, we get:

S5 = 360.56 kg (rod #5 stretched)
S6 = 756.64 kg (rod #6 compressed)

Consider node #6:

Let's write equations on the x and y axes:

200 - S8 * sin7.59 + S9 * sin21.8 + 807.82 * sin21.8 = 0 - on the y-axis
S8 * cos7.59 + S9 * cos21.8 - 807.82 * cos21.8 = 0 - on the x-axis

Just as in the 3rd node, we find our unknowns.

S8 = 756.64 kg (rod #8 compressed)
S9 = 0 kg (rod #9 zero)

Consider node #5:

Let's make equations:

200 + S7 - 756.64 * sin7.59 + 756.64 * sin7.59 = 0 - on the y-axis
756.64 * cos7.59 - 756.64 * cos7.59 = 0 - on the x-axis

From the 1st equation we find S7:

S7 = 200 kg (rod #7 compressed)

As a test of our calculations, consider the 4th node (there are no forces in the rod No. 9):

Let's write equations on the x and y axes:

200 + 360.56 * sin33.69 = 0 - on the y-axis
-360.56 * cos33.69 - 450 + 750.05 = 0 - on the x-axis

In the 1st equation it turns out:

In the 2nd equation:

This error is acceptable and is most likely due to the angles (2 decimal places instead of 3).
As a result, we get the following values:

I decided to double-check all our calculations in the program and got exactly the same values:

Selection of the section of the truss elements

At metal truss calculation after all the internal forces in the rods are found, we can proceed to the selection of the section of our rods.
For convenience, we summarize all the values in a table.

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Shed roof - perhaps the simplest version of the roof. This type of construction is ideal for arranging a garage, veranda, various small-sized buildings, but can also be used in the construction of a small residential building. If you know how to make a shed roof with your own hands, what materials to use and how to properly carry out installation work, then you can not involve builders in these works.

When choosing the type of roof structure, it is important to know the advantages and disadvantages of each option. Only in this case it will be possible to determine the one that is ideal in a particular case. But, since in this material we are talking about a shed roof, we should describe its advantages and say a few words about the disadvantages.

Advantages of a pitched roof:

maximum simplicity of design - you can build it yourself, with little building skills;
the possibility of using any roofing material;
slight windage, which allows you to equip such a roof even in windy areas;

Important! When building a roof on windy areas, it is important to consider the wind rose.

light weight;
the ability to save money and building materials;
if necessary, even under such a roof, you can equip a small attic.

But a shed roof is not without its drawbacks. These include:

modest appearance, although if desired, even such a roof can be turned into a real work of art;
the fact that the attic and attic will not turn out large.

Design features

Despite the fact that the design of a shed roof is quite simple, it is still necessary to take into account a number of nuances when designing this option. In general, when developing a shed roof project, the most important thing is to choose the right direction of the slope. To do this, it is enough to know the wind rose of the area where the construction is taking place. If the roof is properly oriented, then even the strongest wind is not afraid of it. And the debris or snow accumulating on the roof will simply be carried away by him.

Project of a house with a pitched roof

Attention! If the shed roof is incorrectly oriented relative to the direction of the wind, then it is highly likely that it will simply be torn off. Data on the wind rose can be found at the meteorological center.

Shed roofs can be both non-ventilated and ventilated. The first are often arranged over awnings, terraces. They have a small angle of inclination - about 3-6 degrees. You can refuse the need to create a number of additional structural elements, and therefore simplify the design itself. But you need to take care of such a roof more carefully - it is not enough just to clean off the snow to reduce the snow load, it is important to ensure that the tree is treated with moisture-proof compounds.

A ventilated roof is installed on houses or baths. But here it is already required to make the roof in a slightly different way, since in such rooms it is necessary to provide a special microclimate. In this case, it is necessary to attend to the arrangement of layers of waterproofing and ventilation.

In any case, the truss system for a shed roof is quite simple. That is, in this case, the rafters abut with one edge against the Mauerlat, a pediment is equipped, which makes it possible to make a certain angle of inclination.

The design of the rafter system will depend on the width of the roof. That is, if the distance between the supports of the rafters is about 4.5 m or less, then the legs do not need to be strengthened additionally. If the span is larger, up to 6 m, then rafter legs are installed. And if the span is 6-12 m, then in the middle of the span a run is installed under the rafter legs, and rafter legs are mounted on both sides of it. If the span reaches 16 m, then the installation of two supports from the run, racks and bed will be required.

And how to choose the right profile, calculate the farm, make jumpers in it and install, we will now tell you in detail. To do this, we have prepared for you detailed workshops for making such farms, video tutorials and valuable tips from our experts!

Due to the fact that such trusses have a high bearing capacity, they are placed under any roofing materials, regardless of their weight.

The use in the construction of metal trusses from new or rectangular closed profiles is considered one of the most rational and constructive solutions. And for good reason:

The main secret is in savings due to the rational shape of the profile and the connection of all elements of the lattice.
Another valuable advantage of profile pipes for use in their manufacture of trusses is equal stability in two planes, excellent streamlining and ease of use.
With all their low weight, such trusses can withstand serious loads!

Stage II. We acquire a quality profile

So, before drafting future farms, you first need to decide on such important points:

contours, size and shape of the future roof;
material for the manufacture of the upper and lower chords of the truss, as well as its lattice;

Farms are built from a profile pipe of such types of sections: rectangular or square. These are available in different section sizes and diameters, with different wall thicknesses:

We recommend those that are specially sold for small buildings: these go up to 4.5 meters long and have a section of 40x20x2 mm.
If you will make farms longer than 5 meters, then choose a profile with parameters 40x40x2 mm.
For a full-scale construction of the roof of a residential building, you will need profile pipes with the following parameters: 40x60x3 mm.

Be sure to consider snow and wind loads in your area when designing. After all, when choosing a profile (in terms of the load on it), the angle of inclination of the trusses is of great importance:

You can more accurately design a truss from a profile pipe using online calculators.

Stage III. We calculate the internal stress of the trusses

SNiP 2.01.07-85 (impacts, loads).
SNiP p-23-81 (data on steel structures).

Please review these documents if possible.

Roof shape and slope

So, in total there are three main options for making a truss, depending on the slope of the roof:

from 6 to 15°;
from 15 to 20°;
from 22 to 35°.

Those. follow this rule: the lower the weight, the greater the height of the truss. But if we already have a complex geometric shape, then you need to choose a different type of truss and gratings.

Types of trusses and roof shapes

Here is an example of specific trusses for each type of roof (single, double, complex):

Let's look at the types of farms:

triangular trusses are a classic for making the base for steep roof slopes or sheds. The cross section of pipes for such farms must be selected taking into account the weight of the roofing materials, as well as the operation of the building itself. Triangular trusses are good because they have simple shapes, are easy to calculate and execute. They are valued for under-roofing providing natural light. But we also note the disadvantages: these are additional profiles and long rods in the central segments of the lattice. And also here you will have to face some difficulties when welding sharp reference corners.
The next view is polygonal farms from a profile pipe. They are indispensable for the construction of large areas. Their welding is already of a more complex shape, and therefore they are not designed for lightweight structures. But such trusses are distinguished by greater metal savings and strength, which is especially good for hangars with large spans.
It is also considered strong truss with parallel belts. Such a farm differs from others in that it has all the details - repeating, with the same length of rods, belts and gratings. That is, there are a minimum of joints, and therefore it is easiest to calculate and cook one from a profile pipe.
A separate species is single slope trapezoidal truss supported by columns. Such a farm is ideal when a rigid fixation of the structure is necessary. She has slopes (braces) on the sides and there are no long rods of the upper crate. Suitable for roofs where reliability is especially important.

A triangular truss with a crossbar is also quite simple, and is quite suitable for building gazebos and change houses:

And here arched farms are already much more difficult to manufacture, although they have a number of valuable advantages:

Your main task is to center the metal truss elements from the center of gravity in all directions, in simple terms, to minimize the load and correctly distribute it.

Grating types and point load

Let's see what is the advantage of one or another type of lattice in terms of load distribution:

triangular Lattice systems are always used in trusses with parallel chords and trapezoidal truss. Its main advantage is that it gives the smallest total grating length.
Diagonal the system is good at low truss heights. But the consumption of material for it is considerable, because here the entire path of effort goes through the nodes and rods of the lattice. And therefore, when designing, it is important to lay a maximum of rods so that the long elements are stretched and the racks are compressed.
Another view - trussed lattice. It is made in case of loads of the upper belt, as well as when it is necessary to reduce the length of the lattice itself. Here, the advantage is to maintain the optimal distance between the elements of all transverse structures, which, in turn, allows you to maintain a normal distance between the runs, which will be a practical moment for the installation of roof elements. But creating such a lattice with your own hands is a rather laborious task with additional metal costs.
cruciform the lattice allows you to distribute the load on the farm in both directions at once.
Another type of grid cross where the braces are attached directly to the truss wall.
And finally semi-diagonal and rhombic lattices, the most rigid of the listed. Here two systems of braces interact at once.

We have prepared an illustration for you, where we have collected all types of trusses and their lattices together:

Here is an example of how a triangular lattice truss is made:

Making a truss with a diagonal lattice looks like this:

We also note such an unusual version of the manufacture of a farm, when it itself becomes a part or support for another, wooden one:

Stage IV. We manufacture and install farms

We will give you some valuable tips on how to weld such farms on your own without much difficulty right on your site:

Option one: you can contact the factory, and they will make to order all the necessary individual elements according to your drawing, which you will only have to weld on the spot.
The second option: purchase a ready-made profile. Then you will only have to sheathe the trusses from the inside with boards or plywood, and in between lay insulation if necessary. But this method will cost, of course, more expensive.

Here, for example, is a good video tutorial on how to lengthen a pipe by welding and achieve the perfect geometry:

Here is also a very helpful video on how to cut a pipe at a 45° angle:

So, now we come directly to the assembly of the farms themselves. The following step-by-step instructions will help you deal with this:

Step 1: Prepare the trusses first. It is better to weld them in advance directly on the ground.
Step 2. Install vertical supports for future farms. It is imperative that they are truly vertical, so test them with a plumb line.
Step 3. Now take the longitudinal pipes and weld them to the support posts.
Step 4 Raise the trusses and weld them to the longitudinal pipes. After that, it is important to clean all junctions.
Step 5. Paint the finished frame with special paint, having previously cleaned and degreased it. In this case, pay special attention to the junctions of the profile pipes.

The next important point: profile pipe trusses are heavy in weight, and therefore you will need the help of at least one more person. In addition, help will not hurt in such tedious and painstaking work as sanding metal before cooking. Also keep in mind that you will need to cut a lot of farms for all elements, and therefore we advise you to either purchase or build a home-made machine like that in our master class. Here is how it works:

Stage V. We clean and paint finished trusses

That's all, the profile pipe farm is ready! All that remains is the finishing work on sheathing the trusses from the inside with finishing and from the outside with roofing material:

One of the most popular and simple roof designs is. When building small types of buildings at home or in a suburban area, a shed roof is an excellent choice because it is possible to use inexpensive roofing material as a roof, a minimum consumption of building materials and ease of installation are required.

Shed roofs are usually made during the construction of small outbuildings, garages or baths.

The choice of such a roof design will be the most optimal solution if the construction of a bath is planned for existing buildings in the form of an extension, or when it is required to organize snow dumping from the roof on a strictly defined side (for example, so that snow dumped from roofs).

Shed roof device.

According to its design, a pitched roof has, of all types of pitched roofs, perhaps the simplest design.

Due to the support of the roof on walls of different heights, in the simplest case, its slope can be carried out.

Most simple shed roof construction- beams from a bar, from wall to wall with a crate and a coating of rolled materials (for example, roofing felt), it is quite suitable for a bath that has an insulated ceiling.

The angle of the pitched roof.

Based on the cost of building materials, coating material, wind pressure, which depends directly on the roof sail area and the amount of snow load, shed roof slope.

Roof structures experience the greatest load in winter, from snow adhering to it. Therefore, it is recommended to carry out the roof structure with such a slope that snow can roll freely. In this case, the cross section of all building elements is significantly reduced, which reduces the cost of construction.

It is necessary to know at the same time that, depending on the angle of inclination of the slope to the horizon, different types of roofing are also selected. If a roof with a slope of 2-5 degrees or a flat roof can be covered with several layers of roofing material and it will stand for 15-20 years, then when covering the exact same roof with slate, it will leak.

How to choose the right material depending on the angle of inclination is shown in the diagram below:

You can not take into account the weight of the snow, with a roof slope of 45 degrees, since it will roll down by itself. But the wind load experienced and the windage of the roof, while greatly increasing.

The amount of roofing materials needed to cover the roof also increases, with an increase in the angle of inclination of its slope. For a coating with a slope of 45 degrees, more roofing materials will already be required by 1.5 times than for a horizontal roof structure.

Shed roof truss system.

First of all, it depends shed roof truss system from the material of the walls and the dimensions of the building.

When a shed roof is planned to cover a brick building, then the rafters are installed on the mauerlat - a bar with a section of 100 x 100 or 150 x 150, which is laid on two long walls or, in the case of building a log building, on the logs of the upper crown.

The design of the truss system will be quite simple with a span of up to 4.5 meters, including the Mauerlat, as well as the rafters resting on it.

If the span is up to 6 meters, then a rafter leg will be added to the structure, which rests on the bed and serves to give sufficient bearing capacity to the rafters.

In the design of the truss system, it is required to provide for additional fights and racks if the building is planned to be larger.

It is possible to make a rafter system with hanging or inclined rafters, if the log house is made of timber or rounded logs.

The rafter system with hanging rafters is very often used in the construction of gable roofs. You can use the same scheme for shed roof construction. The essence of the hanging rafters is to lean them on horizontal beams that extend beyond the perimeter of the structure at the point of support.

Designations in the figure: a - a system of hanging rafters, b - a rafter system with a headstock and hanging rafters, c - the same, with additional tightening. 1 - rafter leg, 2 - attic floor beam, 3 - wind connection, 4 - rafter leg, 5 - headstock, 6 - additional horizontal tightening.

Due to the device for passing through the upper crowns of the log house of wooden beams, the use of a system with hanging rafters will somewhat complicate the design. But the forces transmitted from the rafter legs are more evenly unloaded and do not act on the walls.

As you can see, special secrets pent roof construction does not possess and you can do it yourself if you wish.

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