Today, trusses made of profile pipe are rightfully considered an ideal solution for the construction of a garage, a residential house and household buildings. Strong and durable, such structures are inexpensive, fast in execution, and anyone who knows at least a little about mathematics and has metal cutting and welding skills can cope with them.
And how to choose the right profile, calculate the farm, make jumpers in it and install it, we will now tell you in detail. To do this, we have prepared detailed master classes for making farms, video lessons and valuable tips from our experts.
So, what is a farm? This is a construction that binds the supports into a single whole. Among its advantages: high strength, excellent performance, low cost and good resistance to deformation and external loads.
Due to the fact that such trusses have a high load-bearing capacity, they are put under any roofing materials, regardless of their weight.
The use of metal trusses made of rectangular closed profiles in the construction is considered one of the most rational solutions. And for a reason:
The truss trusses differ in the shape of the belts, the type of cross-section of the rods and the types of grating. And with the right approach, you will be able to independently weld and install a truss from a profile pipe of any complexity. Even this one:
So, before you make a project of future farms, you first need to decide on such important points as:
Remember one simple thing: the frame of the profile pipe has so-called equilibrium points, which are important to determine for the stability of the entire farm. And it is very important to choose a high-quality material for this load:
Profile pipes for farms come in two types of cross-sections: rectangular or square. They are produced in different diameters, with different wall thicknesses: The
stability of the entire structure is directly proportional to the thickness of the profile, so do not use pipes designed for racks and frames for the manufacture of trusses. Also pay attention to what method the product was made by: electric-welded, hot-deformed or cold deformed.
If you undertake to make farms yourself, take square-section blanks – they are the easiest to work with. Buy a square profile 3-5 mm thick, which will be quite strong and close to metal bars in its characteristics.
Be sure to take into account the snow and wind loads in your area when designing. After all, the angle of inclination of the farms is of great importance when choosing a profile:
You can more accurately design a farm from a profile pipe using online calculators.
We will only note that the simplest structure of a truss made of a profile pipe consists of several vertical racks and horizontal levels on which rafters for the roof can be attached. You can buy such a frame ready-made, even under the order in any city of Russia.
The most important and responsible task is to correctly calculate the truss from the profile pipe and select the desired format of the internal grid. To do this, we will need a calculator or other software similar to it, as well as some tabular data of SNIPS that are responsible for this:
If possible, read these documents.
What kind of roof is the farm needed for? Single-pitched, gable, domed, arched or hipped? The simplest option, of course, is the production of a standard lean-to canopy. But you are also able to calculate and make quite complex farms yourself:
A standard truss consists of such important elements as the upper and lower belt, struts, braces and auxiliary struts, which are also called sprengels. Inside the trusses there is a system of gratings, welded seams, rivets, special paired materials and scarves are used to connect the pipes.
And, if you are going to make a roof that is complex in 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, when building a small country house, garage or cabin, the so – called polonso farms 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 belt is made polyline, and then it is 0.23 of the flight length. It is very convenient for the internal space of the room.
So, there are three main options for making a truss, depending on the slope of the roof:
What is the difference, you may ask? For example, if the angle of the structure is small, only up to 15°, then it is rational to make the trusses trapezoidal. 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 length of the flight.
I.e., follow this rule: the lower the weight, the higher the height of the truss should be. But if we have already a complex geometric shape, then you need to choose a different type of truss and lattices.
Here is an example of specific trusses for each type of roof (single-pitched, gable, complex):
Let's look at the types of trusses:
Here is an example of manufacturing 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 farm with a crossbar is also quite simple, and is quite suitable for the construction of gazebos and cabins:
But
farms are already much more difficult to manufacture, although they have a number of their valuable advantages:
The main thing is your task – to center the elements of the metal truss from the center of gravity in all directions, in simple terms, to minimize the load and distribute it correctly.
Therefore, choose the type of farms that is more suitable for this purpose. In addition to those listed above, the scissor truss, asymmetric, U-shaped, double-hinged, truss with parallel belts and attic truss with and without supports are also popular. As well as the attic view of the farm:
It will be interesting for you to know that a certain design of internal grilles of trusses is selected not for aesthetic reasons at all, but quite practical: 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 the forces are concentrated specifically in the nodes. Then there will be no bending moments in the belts, braces and sprengels – they will work only for compression and stretching. And then the cross-section of such elements is reduced to the necessary minimum, while significantly saving on the material. And you can safely make the farm itself hinged to everything.
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 value 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 sum up: trusses on which the distributed load acts evenly are made of short elements with hinged nodes.
Let's see what is the advantage of this or that type of grid in terms of load distribution:
We have prepared an illustration for you, where we have collected all types of farms and their grids together:
Here is an example of how a truss with a triangular lattice is made: The
production of a truss with a diagonal lattice looks like this:
It cannot be said that one of the types of farms is definitely better or worse than the other – each of them is valuable for less consumption of materials, lighter weight, load-bearing abilities and the method of fastening. The drawing is responsible for what kind of load scheme will act on it. And the chosen type of grid will directly depend on what will be the weight of the farm, the appearance and the complexity of its manufacture.
We also note such an unusual variant of making a farm, when it itself becomes a part or support for another, wooden one:
We will give you some valuable tips on how to cook such farms on your own without any special difficulties right on your site:
Here, for example, is a good video lesson on how to lengthen a pipe by welding and achieve an ideal geometry:
Here is also a very useful video on how to cut a pipe at an angle of 45°:
So, now we come directly to the assembly of the farms themselves. This step-by-step guide will help you cope with this:
What else do those who make such farms at home face? First, think in advance about the support tables on which you will put the farm. 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 bridges-supports that will be slightly wider than the lower and upper girdle of the truss. After all, you will manually measure and put jumpers between the belts, and it is important that they do not fall to the ground.
The next important point: the trusses from the profile pipe are too heavy for weight, and you will need the help of at least one more person. In addition, it will not hurt to help in such tedious and painstaking work as sanding the metal before cooking.
Also, in some structures, it is necessary to combine different types of trusses to attach the roof to the wall of the building:
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 homemade machine according to the type that is in our master class. Here's how it works:
In this way, step by step, you will draw up a drawing, calculate the truss grid, make blanks and weld the structure already in place. Moreover, you will also have the remnants of profile pipes in your consumption, so you will not need to throw anything away – all this will be needed for secondary parts of the canopy or hangar!
After you install the trusses in their permanent place, be sure to treat them with anti-corrosion compounds and paint with polymer paints. The paint, which is characterized by durability and UV resistance, is ideal for this purpose: