If you want to build an economy class house, you can use concrete blocks as a wall material. They can be classified according to several criteria, for example, compressive strength. On sale are many brands ranging from M50 to M300. As for frost resistance, the described products are able to withstand from 15 to 200 cycles of freezing and thawing. You can find out about this value by marking, which looks, for example, like this: F50.
If you plan to engage in low-rise construction, you should purchase blocks of the brand M75 or higher. Quite inexpensive wall material are hollow blocks. It is convenient to reinforce the masonry of them. This allows you to build houses, the bearing part of the walls 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 a stable size and is manufactured by vibrocompression. The standard product has the following parameters: 390 x 190 x 190 mm. Width can be from 190 to 290 mm, however this value can be changed by the supplier. But as for the 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 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 home should interest you. For example, a product with dimensions of 390 x 190 x 188 mm costs 52 rubles. But the wall sand-cement block with the same parameters costs 42 rubles.
The advantages of building concrete blocks
Before starting the construction of your future home, you should definitely familiarize yourself with the pros and cons of a concrete block house. The material is characterized by high strength and durability, it is earthquake resistant. An additional advantage is fire resistance and noise reduction. The economic benefit is obvious: one wall will cost twice as much brickwork of the same area.
Building a house from concrete blocks is also beneficial for the reason that decorating the facade is quite simple, as well as waterproofing and insulation. The walls are smooth, so there will be no problems with installing siding. This also applies to lining. Modern industry produces blocks of various formats, textures and colors. Products can even be polished or roughened. But if you do not plan to leave the walls in their original form, you can cover them with clinker bricks, forming a ventilated facade. Some people prefer corrugated panels or plaster.
The main disadvantages of blocks
Before building a house of concrete blocks, you should understand the main disadvantages of this material. Among others - an impressive weight. This drawback may entail yet another - the need to use additional equipment, for example, a manipulator.
Such products also have high thermal conductivity, therefore, require additional wall insulation. Sometimes the benefits of construction result in high costs of thermal insulation and cladding, so before starting work, you need to calculate the budget and choose materials.
Masonry features: reinforcement
When building a house of concrete blocks, you must carry out the reinforcement. The rods are laid in horizontal and vertical directions. In the latter case, the rods should be placed in coaxial voids. Reinforcement is made on both sides along the door and window openings. In those places where the walls are adjacent, as well as where the corners are located, the distance between the rods should be no more than 2 m.
A concrete belt must be placed around the perimeter of the load-bearing walls. It should be at the level of overlap. The belt is a strapping beam, which is complemented by horizontal reinforcement. The ceiling and the roof structure are supported and fixed on it. With the device of a monolithic belt and jumpers that will be located above the openings, tray blocks will act as a formwork.
When building a house from concrete blocks, you must remember that the reinforced areas along with the ceilings will form a strong and rigid frame. This will ensure the stability of the building, which will not hinder even the small thickness of the bearing walls. When choosing fittings, you should prefer rods of classes A-II and A-III, the diameter of which will be a limit of 10 to 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 plates can be used as thermal insulation; their thermal conductivity coefficient can be from 0.025 to 0.041 W / m ° .
You can determine the thickness of the insulation by making calculations. If we are talking about three-layer walls, then the following characteristics of the masonry should be taken into account. Carrier layer of material with a thermal conductivity of 1.40 W / m ° C. The facing layer is made of vibro-pressed concrete brick with a masonry density of 2100 to 2200 kg / m 3 , and the thermal conductivity should be 1.20 W / m ° C.
If the facing layer will consist of hollow vibropressed concrete blocks with an average density of 2100 to 2200 kg / m 3 , then the masonry density should be 1500 kg / m 3 and the thermal conductivity should be 0.60 W / m ° C.
EPP, mineral wool and polystyrene foam for thermal insulation of walls
If you do not plan to use mineral wool boards , you can replace them with polystyrene foam with a flame retardant, you can recognize them by marking PSB-S. Extruded polystyrene foam, designated by the manufacturer as EPSP, is also suitable. But in the case of mineral wool, it is necessary to choose semi-rigid canvas with a synthetic binder. The insulation density may be equal to the limit of 75 to 125 kg / m 3 .
Foundation construction
If you plan to build the foundation of the house from concrete blocks, you will get a design with high frost resistance and strength. This allows the use of vibropressed concrete blocks for the construction of a basement or strip foundation. You should purchase brand material not lower than M100. Masonry reinforcement should be done in horizontal and vertical directions. 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 to the length of the blocks, otherwise the product will have to be cut, and inserts, for example, made of bricks, should be made in the foundation, which will help weaken the structure.
Why it is worth abandoning blocks during the construction of the foundation
In general, experts do not recommend laying concrete blocks under the house, since their standard width does not fit well with the thickness of the walls. The base walls 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. The prefabricated foundation is well suited for the house that will be built on a site with a uniform soil and without a large slope. The groundwater level during seasonal fluctuations should not reach the bottom of the foundation. If the groundwater in the territory is too high, it is better to fill the strip foundation of concrete.
Finally
The house of concrete blocks provides for the laying of load-bearing walls. Outside, the facade is protected by thermal insulation. To create a barrier to the insulation and give the external walls a decorative look, they are faced in one way or another. Blocks are laid on a cement-sand mortar. In this case, the mixture is applied only to longitudinal ribs and an end face, which is also called a jab. But the transverse ribs can be left dry.