Polycarbonate is an ideal material for the construction of canopies. It allows you to get a light structure with a transparent roof through which sunlight penetrates. As a rule, the frame is made of profiled pipes. In order for the entire structure to be durable, it is necessary to correctly calculate the polycarbonate canopy.
What the frame consists of
Before starting the calculation of the canopy, you must clearly understand what elements it consists of. And there are only a few.
Racks, as the name implies, are the elements on which the entire canopy lies. As a rule, this is a profiled pipe with a height of 2.2-2.8 meters. Its height depends on the method of attachment. If it is attached with anchors to a mortgage concreted in the ground, then its height is taken to be 2.2 meters. In cases where the rack is concreted or buried, then the height is taken to be 2.8 meters.
Arches and trusses serve to strengthen the canopy. The latter are most often installed two. But the exact number of arches will tell onlycarried out calculation of the canopy. This value depends on the dimensions of the structure.
Truss is a structural element that connects support posts and logs.
Polycarbonate sheets are attached to structural elements called guides. For this, thermal washers are used. Their location and step frequency depend on the distance between the bearing supports and the type of polycarbonate (its thickness).
Canopy installation steps
In order to correctly calculate a canopy from a profile pipe, it would be useful to understand the whole process as a whole. It consists of several stages. Arches are attached to fixed racks. In this case, the angle between them should be exactly ninety degrees. The resulting sections are attached to the embedded anchors. Farms are attached to the same supports. The angle between trusses and arches is also a right angle (that is, ninety degrees). The final stage in the manufacture of the frame is the fixation of the guides. They are attached to the top of the arches. On this frame is ready. After painting it, you can fix polycarbonate sheets.
Construction errors to consider when calculating
The construction of sheds is often done with errors. They affect not only the choice of the type of construction, but also the calculation of the metal canopy carried out as a result.
A common mistake is choosing a sloped canopy. Often they make a structure on two pillars and tilted to the windward side. This is far from the best option for permanent use (for example, for parking a car). Danger awaits if the wind changes direction. The canopy in this case can be compared with the wing of an aircraft. A lifting force is formed between it and the ground, which can easily demolish the canopy. Even if there are four pillars, it will not always save.
Tilted canopies are suitable for situations where the structure is attached to the building. Free-standing sloping canopies must be made with roundings. Moreover, the convex part is oriented “towards” the wind.
Types of canopies
Depending on the supporting elements, there are several types of canopies:
Stand alone. They have vertical supports installed around the entire perimeter
Beam-bearing, which are attached to the building on one side. They have one side held by support pillars. The second lies on a beam attached to the wall of the building
Console-support. They differ from the previous view in that here brackets or mortgages are attached to the wall
Console, which are held entirely by mortgages. Usually these are small canopies above the door
The calculation of each type of canopy is carried out according to different schemes.
Types of awnings
According to their design, suspended structures can be of three types:
Single-pitched, in which the roof is tilted to one side
Gable with two slope directions
Arched, in which the roof is made in the form of a semicircle (arc)
Data collection
Calculation of a canopy from a profile pipe must begin with the collection of the necessary information. She ismust include the following data:
Material specifications
The purpose of the structure
Shape of construction
Data on wind and snow loads (they are presented in special tables for each specific region)
The calculation of the canopy is carried out taking into account the information described above. It includes formulas and calculations. Not everyone can understand them. The best option is to use special programs and calculators. Today, there are plenty of them on the Internet.
Cantilever visors over the entrance
Cantilever awnings depend on the size of the porch. In accordance with the requirements of regulatory documents, the platform in front of the door should be one and a half times the width of the door. The average door width is 0.9 meters. It turns out that the minimum size of the upper platform is 1.35 m (0.9 x 1.5=1.35). This value is equivalent to the recommended canopy depth.
As for the width of the visor, everything is simple here. It is made 0.6 meters more than the width of the door. On each side, the visor should protrude 0.3 meters.
Sheds are calculated in such a simple way. The calculation of the structure with standard values leads to the following result: depth - 0.9-1.35 m, width - 1.4-1.8 m.
Cantilever-support canopies over the door
These types of visors are arranged over the entire platform with the capture of steps. The calculation of the depth of the canopy over the site is calculated similarly to the previous option. To it is addedthe part above the steps. It directly depends on their number. For each step, about 0.25-0.32 m is added.
The width depends on the width of the stairs, on both sides of which 0.3 meters are added. If the standard width of the steps in front of the door is 0.8-1.2 meters, then we get the width of the canopy 1.1-1.5 meters.
Consider the option with a ladder of three steps and a platform of standard sizes. The depth will be about 1.65-2.31 meters (0.9 + 3 x 0.25 or 1.35 + 3 x 0.32). The width under the same conditions is 1.4-1.8 meters. It is calculated as follows: 0, 8 + 0, 3 + 0, 3 or 1, 2 + 0, 3 + 0, 3. Two calculation options consider the minimum and maximum value of the standard parameters.
Shed awnings adjacent to the building
Calculation of a shed canopy, which is adjacent to the house on one side, is carried out with a minus of half of the vertical supports. Another important point: the joints of the sheets must be above the profile. This means that a distance of 1260, 2050 or 2100 millimeters must be maintained between the profiles, corresponding to the size of the polycarbonate sheet. The average width of the canopy is three meters. With this size, there is enough space even for a car. On polycarbonate at this width it will sag. He needs a rafter system.
To begin with, the calculation of the material is carried out. A canopy attached to the house, with such dimensions, will have six vertical risers. They will all be on the same side. If the structure is freestanding, then twice as many supports are needed (that is, twelve, six from eachsides). A support is installed for each rafter leg.
Single freestanding canopy
Calculation of a stand-alone structure must take into account the load carried by precipitation. The design will be as rigid as possible if it is made in the shape of a triangle.
Calculation of the canopy is carried out taking into account conditionally accepted values. With a polycarbonate sheet size of 2.1 x 0.6 m, the width of the roof is assumed to be six meters, and the length is 10.6 meters. The most optimal option: a slope height of 2.4 meters and 11 rafter sections. In such a situation, six profiles will be required (with a standard length of six meters). Instead of eleven, you can make only two triangles. This will reduce the amount of materials used. This option is suitable for regions with average rainfall.
Calculation of a gable canopy
The principle of calculation is similar to single-slope structures. The main thing is to achieve structural rigidity. And this is done due to the same triangles. Their optimal number is calculated as follows. Each linear meter of the canopy is divided by a vertical profile. The resulting rectangle is divided into two triangles.
Calculation of arch structures
Arched awnings are the most complex structures. The need for material is directly dependent on the convexity of the roof. This means that the steeper the bulge, the more materials will have to be spent.
Save in this case, you can onlyon the truss system. With the dimensions of the canopy considered earlier (10.6 x 6 meters), two or three systems will suffice (two at the edges, one in the middle). The rest of the "legs" will be arcs. It is not necessary to connect their ends. The metal profile that is used to make the truss is strong enough. It will be enough to provide the necessary rigidity. The main thing is that the farm is firmly attached to the risers.
If you make an arched canopy with such dimensions (for example, for a car), then you will need the following materials:
- Six profiles, curved in the shape of an arc, with a length of six meters. The ends of three of them are connected by a jumper. It is also recommended to divide them into several triangles to increase the rigidity of the structure.
- For each arc, two supports are needed (under each edge). That is, in total they need twelve (2 x 6).
- Longitudinal beams are attached along the edges, along the pillars and along the roof. You will need six in total.
Calculation of the main structural elements
Calculation of the pipe section for a canopy depends on the height of the structure itself and the number of columns. If the size of the structure does not exceed five meters, the pipe is selected with a cross section of 6-8 centimeters. For larger sizes, the number of risers should be increased. To avoid this, you can choose a profile with a large cross section. For example, 10 centimeters.
The size of the crate will depend on the thickness of the polycarbonate and the size of the canopy. If the sheet of plastic has a thickness of one centimeter, and the canopy has dimensions of 6 x 8 meters, then the crate will be assembled in increments of one meter. These values are in accordance with the loads. For this, there are special tables that take into account the magnitude of the load and the thickness of the polycarbonate. An example of this table can be seen in the photo below. It is designed for polycarbonate with a thickness of six, eight, ten and sixteen millimeters.
The calculation of the arched canopy involves the calculation of farms and their number. It is the dimensions of the trusses that determine the width of the entire canopy. To determine them, you need to know the following information:
Truss dimensions
Material size (polycarbonate)
Metal resistance
Method of fastening elements (welding, bolting, and so on)
Value of loads (in accordance with regulatory documents)
Steel structures according to SNiP
The size of the canopy is chosen according to the size of the materials. If a polycarbonate sheet is six meters long, then it is either used as a whole or cut into two parts. Of course, you can cut into more pieces. But this will generate waste. Thus, the roof will be either six meters or three meters. Any length can be chosen, depending on personal preferences.
