If you want to build an economy class house, you can use concrete blocks as wall material. They can be classified according to several criteria, such as compressive strength. There are many brands on sale ranging from M50 to M300. As for frost resistance, the described products are able to withstand from 15 to 200 freeze and thaw cycles. You can find out about this value by marking, which looks, for example, like this: F50.
If you plan to do low-rise construction, you should purchase blocks of the M75 brand or higher. Quite inexpensive wall material are hollow blocks. It is convenient to reinforce masonry from them. This allows you to build houses, the bearing part of the wall of which will have a width of one block, which is 190 mm. This applies to a two-story building.
The described material has high frost resistance and impressive strength. It has stable dimensions and is manufactured by vibrocompression. The standard product has the following parameters: 390 x 190 x 190 mm. The width can be equal to from 190 to 290 mm,however, this value can be changed by the vendor. But as for partition and facing products, their width is 90 mm.
One block weighs no more than 17.5 kg. It is based on a cement-sand mixture, and the technology involves pressing and vibration. The latter allows you to make the concrete mixture more liquid and reduces the moisture content. At the same time, shrinkage is zero, which allows the solution to be located as evenly and densely as possible under the influence of the press throughout the entire volume. As a result, it is possible to obtain concrete with a dense packing of aggregate grains. The material itself acquires low porosity. The sizes and prices of concrete blocks for the house should interest you. For example, a product with dimensions of 390 x 190 x 188 mm costs 52 rubles. But a sand-cement wall block with the same parameters costs 42 rubles.
Pros of building with concrete blocks
Before you start building your future home, you should definitely familiarize yourself with the pros and cons of a house made of concrete blocks. The material is characterized by high strength and durability, it is earthquake resistant. An additional advantage is fire resistance and the ability to reduce noise. The economic benefit is obvious: one wall will cost twice as much as brickwork of the same area.
Building a house from concrete blocks is also beneficial for the reason that finishing the facade is quite simple, as well as waterproofing and insulating. The walls are smooth, so there will be no problems with installing siding. This also applies to lining lining. Modern industry produces blocks of different formats, textures and colors. Products can even be polished or rough. But if you do not plan to leave the walls in their original form, they can be overlaid with clinker bricks, forming a ventilated facade. Some prefer corrugated panels or plaster.
The main disadvantages of blocks
Before you build a house from concrete blocks, you must understand the main disadvantages of this material. Among others - an impressive weight. This disadvantage may lead to another one - the need to use additional equipment, for example, a manipulator.
Such products also have high thermal conductivity, so they require additional wall insulation. Sometimes the benefits of construction turn into high costs for thermal insulation and cladding, so before starting work, it is necessary to calculate the budget and select materials.
Features of masonry: reinforcement
When building a house from concrete blocks, you must reinforce. The rods are laid in horizontal and vertical directions. In the latter case, the rods must be placed in coaxial voids. Reinforcement is made on both sides along the door and window openings. In those places where the walls adjoin, as well as where the corners are located, the distance between the bars should be no more than 2 m.
The concrete belt must be placed along the perimeter of the load-bearing walls. It should be at the level of the overlap. Beltis a strapping beam, which is complemented by horizontal reinforcement. The ceiling is supported and fixed on it, as well as the roof structure. When installing a monolithic belt and lintels, which will be located above the openings, tray blocks will act as formwork.
When building a house from concrete blocks, you must remember that the reinforced sections, together with the ceilings, will form a strong and rigid frame. This will ensure the stability of the building, which will not interfere with even the small thickness of the bearing walls. When choosing rebar, you should prefer rods of classes A-II and A-III, the diameter of which will be between 10 and 32 mm.
Wall insulation
The concrete block for the house, the price of which is mentioned above, forms the basis of a kind of wall cake from the carrier layer, thermal insulation and facing material. The latter is the same masonry on a cement-sand mortar. When choosing a heater, you should prefer one whose thickness does not exceed 150 mm. Mineral wool or polymer boards can be used as thermal insulation, their thermal conductivity coefficient can be from 0.025 to 0.041 W/m°C.
You can determine the thickness of the insulation by making calculations. If we are talking about three-layer walls, then the following masonry characteristics should be taken into account. The carrier layer is made of a material with a thermal conductivity coefficient of 1.40 W/m°C. Facing layer of vibropressed concrete bricks with masonry density from 2100 to 2200 kg/m3,the thermal conductivity coefficient in this case should be 1.20 W / m ° C.
If the facing layer will consist of hollow vibrocompressed concrete blocks with an average density of 2100 to 2200 kg/m3, then the masonry density should be equal to 1500 kg/m 3, and the coefficient of thermal conductivity is 0.60 W/m°C.
EPP, mineral wool and expanded polystyrene for wall insulation
If you do not plan to use mineral wool boards, then you can replace them with polystyrene foam boards with flame retardant, you can recognize them by the PSB-S marking. Extruded polystyrene foam, designated by the manufacturer as XPS, is also suitable. But in the case of mineral wool, it is necessary to choose semi-rigid sheets on a synthetic binder. Thermal insulation density can be equal to the limit of 75 to 125 kg/m3.
Building the foundation
If you plan to build the foundation of a house from concrete blocks, you will get a structure with high frost resistance and strength. This allows the use of vibropressed concrete blocks for the installation of a plinth or strip foundation. You should purchase material of a brand not lower than M100. Reinforcement of the masonry must be done in the horizontal and vertical direction. All voids in the blocks are filled with concrete.
The height of the base must be matched to the size of the products. This indicates that almost always the foundation is higher than required. It is important to adjust the dimensions of the base tothe length of the blocks, otherwise the products will have to be cut, and inserts, for example, of brick, will be made in the foundation, which will weaken the structure.
Why you should abandon blocks when building a foundation
In general, experts do not advise laying concrete blocks under the house, as their standard width does not go well with the thickness of the walls. The walls of the base are much thicker than necessary. The design itself will be unnecessarily material-intensive, expensive and heavy.
Small-format concrete blocks are an alternative solution. They can be hollow or solid. A prefabricated foundation is well suited for a house that will be built on a site with uniform soil and without a large slope. The groundwater level during seasonal fluctuations should not reach the base of the foundation. If the groundwater in the territory is too high, then it is better to pour a strip foundation of concrete.
In closing
A house made of concrete blocks provides for the laying of load-bearing walls. Outside, the facade is protected by thermal insulation. To create a barrier in front of the insulation and give the external walls a decorative look, they are faced in one way or another. The blocks are laid on a cement-sand mortar. The application of the mixture in this case is carried out only on the longitudinal ribs and the end face, which is also called a poke. But the transverse ribs can be left dry.
