Everyone has seen such large bricks with numerous through holes. These are porous ceramics - stones. The standard defines stone as a large-sized hollow ceramic product intended for masonry. Specially shaped holes and firing at high temperatures allow not only to lighten the product without reducing the strength grade, but also to fill it with air, which, as you know, is an excellent heat insulator. But the most interesting is "stored" in these thin walls, bridges, on the one hand strong from firing, and on the other - filled with thousands of micro cavities, which are also filled with air. It is during the production process that sawdust is specially added to the clay, which, when burned, form "warm pores".
When calculating construction costs, it is important to take into account not only the cost of the building materials themselves, but the gains and losses that are obtained when choosing them. For example, if we are talking about the construction of external walls of a house, it is necessary to take into account the level of resistance to heat transfer of the structure, which ultimately affects the cost of heating and cooling the air in the room. The higher the resistance, the more energy efficient the building.
With the right choice of materials for external walls, you can increase the actual area of the room due to thinner wall layers. Of course, the level of resistance to heat transfer of the masonry must comply with the standards. We offer you a comparison of large-format blocks of all well-known manufacturers in terms of thermal performance and economic feasibility of use.
The purpose of this analysis is to find out which large-format blocks are the most economically advantageous to use. For comparison, let's take the blocks of the most popular brands in Moscow and the Moscow region:
KERAKAM, POROTHER, RAUF, BRAER, GZHEL.
What blocks are it enough to lay in the outer wall in only one layer, while observing the norms of resistance to heat transfer?
For each brand, we will calculate what kind of heat transfer resistance the outer wall will have, and select those brands for which this indicator will not be lower than the norm when laying blocks in just one layer.
So, in Moscow, the norm of resistance to heat transfer of external walls is 3.13 m² • ° С / W.
The thermal resistance coefficient of a building structure is equal to the sum of the thermal resistance coefficients of the materials that make up this structure. That is, if the outer wall includes a layer of facing bricks on a cement-sand mortar, a layer of blocks on the same mortar and a cement-sand layer applied inside the room, then the heat transfer resistance of the wall is determined as follows:
R = 1 / αv + R1 + R2 + R3 + 1 / αn,(1)
Where
αw = 8.7 W / (m² • ° С) is the heat transfer coefficient of the inner surface of the enclosing structures, αн = 23 W / (m² • ° С) is the heat transfer coefficient (for winter conditions) of the outer surface of the enclosing structure, The values R1, R2, R3 are the heat transfer resistance of each individual layer.
Each of these values is calculated by the formula: R = δ / λ, where δ is the thickness of the material layer, and λ is the coefficient of its thermal conductivity.
R1 - thermal resistance of facing bricks with a thickness of cement-sand mortar (thickness - 0.102 m, and thermal conductivity coefficient - 0.53 W / m ° С):
R1 = δ1 / λ1 = 0.102 / 0.53 m2 • ° С / W = 0.19 m2 • ° С / W
R2 - thermal resistance of blocks based on cement-sand mortar. This indicator will be calculated below separately for each of the selected brands.
R3 is the thermal resistance of the cement-sand mortar applied indoors (thickness - 0.015 m, and the thermal conductivity coefficient - 0.76 W / m ° С):
R3 = δ3 / λ3 = 0.015 / 0.76 m2 • ° С / W = 0.02 m2 • ° С / W
Substituting all these values into formula (1), we get:
R = R2 + (1 / 8.7 + 0.19 + 0.02 + 1/23) m2 • ° С / W
or
R = R2 + 0.37 m² • ° С / W = δ2 / λ2 + 0.37 m2 • ° С / W(2)
Reminder: the higher the R value, the better the building envelope's thermal performance and energy efficiency.
Now let's calculate the resistance to heat transfer of the masonry from the large-format blocks selected for analysis. Their thermal conductivity coefficients specified in the test reports by the manufacturing plants will be applied.
For this we use the formula (2):
R = δ2 / λ2 + 0.37 m2 • ° С / W
substituting into it δ2 - the thickness of the material layer, that is, the block, and λ2 - the coefficient of its thermal conductivity.
For each brand of blocks, we obtain the following indicators of resistance to heat transfer:
KERAKAM 30 SuperThermo: R = (0.30 / 0.123 + 0.37) m2 • ° C / W = 2.81 m2 • ° C / W
KERAKAM 38: R = (0.38 / 0.220 + 0.37) m2 • ° С / W = 2.10 m2 • ° С / W
KERAKAM 38 Thermo: R = (0.38 / 0.180 + 0.37) m2 • ° C / W = 2.48 m2 • ° C / W
KERAKAM 38 SuperThermo: R = (0.38 / 0.121 + 0.37) m2 • ° C / W = 3.51 m² • ° С / W
KERAKAM 44: R = (0.44 / 0.139 + 0.37) m² • ° С / W = 3.54 m² • ° С / W
KERAKAM 51: R = (0.51 / 0.190 + 0.37) m2 • ° С / W = 3.05 m2 • ° С / W
POROTHERM 38: R = (0.38 / 0.170 + 0.37) m2 • ° C / W = 2.61 m2 • ° C / W
POROTHERM 44: R = (0.44 / 0.147 + 0.37) m2 • ° C / W = 3.36 m² • ° С / W
POROTHERM 51: R = (0.51 / 0.161 + 0.37) m2 • ° C / W = 3.54 m² • ° С / W
RAUF 10.7 NF: R = (0.38 / 0.185 + 0.37) m2 • ° C / W = 2.42 m2 • ° C / W
RAUF 14.3 NF: R = (0.51 / 0.185 + 0.37) m2 • ° C / W = 3.13 m² • ° С / W
BRAER Ceramic Thermo 10.7 NF: R = (0.38 / 0.191 + 0.37) m2 • ° C / W = 2.35 m2 • ° C / W
BRAER BLOCK 44: R = (0.44 / 0.191 + 0.37) m2 • ° C / W = 2.67 m2 • ° C / W
BRAER Ceramic Thermo 14.3 NF: R = (0.51 / 0.191 + 0.37) m2 • ° C / W = 3.04 m2 • ° C / W
GZHEL 10.7 NF: R = (0.38 / 0.186 + 0.37) m2 • ° С / W = 2.41 m2 • ° С / W
GZHEL 10,7 NF Termocode: R = (0.38 / 0.146 + 0.37) m² • ° С / W = 2.97 m² • ° С / W
GZHEL 12.3 NF: R = (0.44 / 0.160 + 0.37) m2 • ° С / W = 3.12 m2 • ° С / W
Since the norm for Moscow is 3.13 m² • ° С / W, then only blocks of the KERAKAM 38 SuperThermo, KERAKAM 44, POROTHERM 44, POROTHERM 51 and RAUF 51 brands can be laid in one layer in the outer walls.
How to increase the planned floor space when choosing large-format blocks?
The most advantageous material in terms of freeing up additional space is the one that is thinner than others. Compared to KERAKAM 44, POROTHERM 44 (their thickness is 44 cm), the use of KERAKAM 38 SuperThermo blocks with a thickness of 38 cm increases the area of the room by 0.06 m2, and compared to POROTHERM 51 and RAUF 51 (thickness - 51 cm) - by 0.13 s m² from each running meter of the wall.
It turns out that replacing large 44 cm thick blocks with KERAKAM 38 SuperThermo allows you to get an additional 2.4 m² for every 100 m² of the originally planned area, and if you replace 51 cm thick blocks with them, you get an additional 5.2 m² for each planned 100 m².
How can you reduce foundation costs?
When using KERAKAM 44, POROTHERM 44 or POROTHERM 51, the thickness of the reinforced concrete foundation is 60 cm, and if KERAKAM 38 SuperThermo is used instead, the thickness of the reinforced concrete foundation will decrease to 50 cm, and the cost of the foundation will decrease by more than 18%. For example, in this way, when building a house with an area of 200 m² on the foundation, from 70,000 to 150,000 rubles are additionally saved.
How can you save money on wall construction work?
For one running meter of a wall with a height of 3 meters, 50.4 pieces, that is, 1.14 m³, KERAKAM 38 SuperThermo blocks or 50.4 pieces of KERAKAM 44 are needed, which is 1.32 m³. If you use POROTHERM 44, then you need 52.41 blocks - that's 1.34 m³.
The minimum cost of building 1 m³ of a wall from such blocks is 1200 rubles. Therefore, it turns out that the construction of a wall from KERAKAM 38 SuperThermo will cost 1368 rubles, from KERAKAM 44 blocks - 1584 rubles, and from POROTHERM 44 - 1608 rubles. This means that replacing POROTHERM 44 blocks with KERAKAM 38 SuperThermo blocks reduces wall construction costs by 14.93%.
How much can you reduce the cost of the solution?
The cost of the warm masonry mortar LM 21-P, recommended by all manufacturers, is 360 rubles. for 17.5 kg, which is 20.57 rubles. for 1 kg.
For the construction of 1 m³ of large-format masonry blocks, 60 kg of masonry mortar is required. This means that for 1 KERAKAM 38 SuperThermo block, 1.36 kg of solution for the amount of 28 rubles is needed, for one POROTHERM 44 block - 1.54 kg of solution for the amount of 31.7 rubles, and for each POROTHERM 51 block - 1.75 kg solution in the amount of 36 rubles.
It follows from this that when erecting a wall made of KERAKAM 38 SuperThermo, the cost savings on mortar are significant - compared to POROTHERM 44 blocks, it will be 3.70 rubles, and with POROTHERM 51 - 8 rubles. on the masonry of each block!
So, the most cost-effective brand of large-format blocks is KERAKAM 38 SuperThermo (dimensions: 260x380x219).
Using these blocks for the construction of external walls, their economic efficiency is obvious - the costs of the foundation, construction work and mortar are reduced, the actual area of the interior is significantly increased,at the same time, when laying blocks in one layer, the norms of resistance to heat transfer of the walls are observed.
Small but smart!
The entire range of warm ceramics for the construction of walls of cottages and multi-storey buildings, as well as a large selection of hand-molded and industrial facing bricks from Russian, British and European factories are waiting for you in the Kirill company on Begovaya.
A complex order for the supply of materials for the house is always more profitable!
We offer architects and designers partnership cooperation programs.
