Self-construction of the roof of the house, garage, gazebo, etc. in any case, it includes the calculation of the roof, which will be discussed in this article using several materials as an example.
Before performing the calculation of roofing materials, you should measure the dimensions of the truss structure or take them in the drawings if there is a roof project. The first step is to make sure that all actual dimensions are fully consistent with those stated in the project.
Important: when calculating the roof, you cannot use the usual dimensions of the building along the walls. Usually the end and cornice parts of the roof have overhangs 50-100 cm in size, protecting the walls from moisture penetration. The dimensions of the overhangs should also be taken into account when calculating the roof.
Roof area can be calculated using mathematical formulas learned in high school.
Roof slopes usually have the form of geometric shapes:
- Triangle;
- Rectangle;
- Parallelogram;
- Trapeze.
The figures below show the formulas for calculating the areas of these figures:
The calculation of materials for the roof requires not only knowledge of the total area of \u200b\u200bthe roof. It should also be borne in mind that the total set of roofing usually includes 10-15 items, depending on how complex the shape is. roofs selected, as well as on which roofing cake will be used - a warm attic or a cold attic.
Important: when calculating the roof, you should also calculate the snow load on the roof, which allows you to more accurately calculate the material and rafter system.
Next, various nuances will be considered, which include the calculation of roofing material, depending on the type of material.
Calculation of metal tiles and corrugated board
Decking and metal tiles are sheet materials, the laying of which is carried out with an overlap. In this regard, when calculating them, one should take into account not the nominal width of the sheets, but the useful one. The table shows the values of the useful and actual width of materials of various grades.
When performing calculations, it is also necessary to take into account the value of the vertical overlap, which is usually 10 centimeters for metal tiles and corrugated board. Calculation of the roof of the house should be performed sheet by sheet, taking into account the various features of a particular material.
It is usually recommended to draw a diagram of the roof slopes to scale and superimpose roofing sheets on the diagram, taking into account the overlap during laying, as well as the value of the maximum sheet length:
- The length of a metal tile sheet is from 50 to 650 centimeters;
- The length of the corrugated sheet is from 50 to 1200 centimeters.
Important: you should not purchase sheets of the maximum possible length, since their transportation will cost much more and will block the material savings due to fewer overlaps.
It should also be borne in mind that roof slopes most often they are not rectangular in shape, the upper corners of the sheets of corrugated board and metal tiles are cut off, which increases the consumption of material, which should also be taken into account in the calculation.
When calculating the required amount of material, it is also important to take into account special strips - additional elements 2 meters long, used in the arrangement of such roof elements as:
- Ends;
- Cornices;
- Skates;
- valleys;
- Connections to walls;
- Connections to pipes, etc.
Calculation of flexible and cement-sand tiles
Flexible shingles in the form of small shingles can be easily cut to fit the required dimensions, so you should order a volume of material that exceeds the total roof area by 10%, that is, with a margin. When calculating the usable area of this material in one package, the dimensions of the overlap have already been taken into account by the manufacturer.
Lining carpet manufacturers also recommend ordering in the same volume. Ridge elements, bituminous mastic, valleys, etc. are calculated in accordance with the manufacturer's recommended consumption rates for these materials.
It is quite difficult to independently calculate such a material as cement-sand tiles, since this building material is calculated by specialists on the basis of a specific project.
Accordingly, in order to obtain the most accurate result, it is better to contact qualified specialists - it is not recommended to perform the calculation on your own.
Most roofing systems use waterproofing films, and when building an insulated attic, materials such as vapor barrier and insulation are also required. The area of the waterproofing material coincides with the area of the roof, and the required volumes of vapor barrier and insulation should be calculated based on the size of the attic space and the required thickness of the insulation.
In addition to the roofing material, you should also order ventilation elements, fasteners and other roofing accessories. The easiest way to perform all calculations, including the calculation of the load on the roof, the calculation of materials, etc., is to use a special calculator program.
The use of such a program not only greatly simplifies the calculation of the roof itself, but also minimizes the likelihood of errors and inaccuracies that lead to a decrease in the reliability, efficiency and durability of the roof during operation.
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