For calculation of necessary number of gas-blocks for construction of the house there is simple technique. But before counting, it is necessary to have the project in which the sizes of walls, both external, and internal, the sizes and quantity of door and window openings, quantity and height of floors, pediments, the mansard floor are specified. Besides, it is necessary to decide on type of the block and its dimensions.
Calculation of gas concrete for external walls of the house
For calculation the following project will be considered: one-storey building with sizes of external walls of 6×9 m, height of the first floor of 3 m, is available penthouse with height in 2.5 m, double-pitch roof. Foam concrete block in one layer is applied to laying with length, width and height according to 625×300×250 mm.
Key parameter of foam concrete block is its width which is connected with durability and thermal insulation. When choosing gas concrete it is necessary to consider loads of the block and weather conditions in which this material will be applied.
At first it is necessary to learn how many square meters of walls are available. Perimeter of all walls: (6+9) *2=30 m. Now it is possible to count the area, knowing wall height: 30*3=90 sq.m. It is necessary to subtract the area of all window and door openings from the found size. To consider that the house contains 10 windows with a total area of 18 sq.m and two doors of 4 sq.m. Thus, the total quadrature of walls makes: 90-(18+4)=68 sq.m.
If desired it is possible to consider so-called bandaging of corners. Means that the area of that part of the block which is the share of joint of two walls should be carried only to one of walls.
Now it is possible to define the number of the gas-blocks demanded for construction of the first floor. For this purpose the area is divided into length and height of the block (it is important not to forget to transfer millimeters to meters): 68/0.625/0.250=435.2 pieces (by rounding we have 435 pieces).
Here the gas concrete can be counted not in pieces, and in cubic meters, having increased quadrature of walls by thickness of course, i.e. the foam concrete block: 68*0.300=20.4 CBM.
Calculation of gas concrete for the mansard floor
The penthouse of triangular shape will be considered. Therefore, the area of triangle is defined by the work of the basis on half of height. In this case height - 2.5 m, and the basis (it house width) – 6 m. So, the area of one party of penthouse is: 6*2.5/2=7.5 sq.m, and two parties, according to 15 sq.m.
Penthouses can be triangular, round, pyramidal, broken, symmetric and is not present, etc. Therefore, when calculating walls of the mansard floor it is necessary to take specific geometrical form into account.
Now it is necessary to consider the windows which are available in penthouse. The area of window openings on this floor of 3 sq.m. is accepted. So, the total area of walls of the mansard floor will be: 15-3=12 sq.m. Further it is necessary to count the number of the gas-blocks demanded for construction of penthouse: 12/0.625/0.250=76.8 pieces (we round to 77 pieces). Now it is simple to find total number of blocks for external walls of all house: 435+77=512 gas-blocks.
It is desirable to increase the received quantity by 5% for compensation of fight, probable defects or necessary undercuttings. It is fair also for the number of blocks on internal walls.
Calculation of gas concrete for internal walls of the house
In the project it is assumed that internal load bearing walls are carried out from gas-blocks of the same size, as external, and their general perimeter is accepted equal 12 m. The area of load bearing walls will be 12*3=36 sq.m. The number of blocks is equal to 230 pieces (36/0.625/0.250=230.4 pieces). In the presence of door openings, they should be considered. It was necessary to carry out similar calculations for internal partitions, without forgetting about door openings. As a rule, in this case blocks with smaller thickness, than are used to external and load bearing walls. If calculation of gas concrete is conducted in pieces, then in it length and height of the block are considered. In case of calculation in cubic meters, it is necessary to consider change of thickness of peregorodochny foam concrete block. It is connected with the fact that such block is put by "edge".
Valuation
In most cases the prices of gas-blocks are specified for 1 CBM. Therefore pieces need to be transferred in cubes. The sizes of one block on their total are for this purpose multiplied. For example, for external walls of the house it will be required gas concrete in cubic meters: 0.625*0.300*0.250*512=24 CBM. Now, knowing the price for gas concrete cubic meter, it is easy to define costs of 24 cubes of foam concrete blocks.