Aerated concrete house foundation: how to choose and build correctly?

When choosing a foundation for building from aerated concrete blocks, it is necessary to take into account all the technical characteristics of this material. Aerated concrete is a popular budget material, often used in the construction of residential buildings, cottages and outbuildings. It has a number of advantages, which is why it is in great demand. But houses made of aerated concrete are heavier than buildings made of logs or beams, so here it is worth thinking about a solid foundation.

Aerated concrete is autoclaved aerated concrete. Throughout the history of its existence, it has found application in almost all areas of construction of structural elements of buildings and structures of any type. The characteristic features of this material make it very competitive in the building materials market.

The main advantages of building foundations from this material:

• independence from temperature extremes;
• a light weight;
• fast installation and ease of installation;
• environmental friendliness;
• moderate cost;
• excellent heat and sound insulation;

• high resistance to frost, and due to porosity, water does not penetrate quickly into the material;
• versatility: aerated concrete can be sawn, drilled, thanks to which aerated concrete blocks can be given different shapes;
• at the factories where gas blocks are made, there is a laboratory that controls the quality of the material;
• aerated concrete refers to stone materials, but is considered a fairly light material. Almost any type of foundation is suitable for it, which meets the requirements for rigidity and deformation.

In terms of strength and design solutions, aerated concrete blocks are in no way inferior to the usual brick. Mold and dampness rarely appear in them, they breathe well.

The slab view is one of the options for a shallow or shallow foundation. This is a reinforced concrete slab, under which a layer of sand and gravel is compacted. The slab version for a house made of aerated concrete has the maximum possible bearing capacity, which is achieved due to the large supporting area of ​​the slab that occupies the entire area of ​​the building.

In most cases, the thickness of the slab is between 20 and 40 cm. Monolithic slab-type bases have greater spatial rigidity than a foundation assembled from individual slabs.

The main advantages of a slab foundation:

• ease of installation;
• low cost;
• high bearing capacity;
• the common platform does not undergo local deformation;
• the possibility of using the foundation as a floor for the basement;
• the height of the house can be higher than 2 floors with a load of 20-25 t / m2;
• ease of construction in difficult soils.

The pile foundation has recently become more widespread due to its reliability, versatility and availability of DIY installation. Very often, aerated concrete buildings are erected on screw piles, interconnected by a grillage, in areas with a close occurrence of groundwater.Installation with a monolithic grillage will keep the block masonry from shrinkage cracking.

The tape option is a reinforced concrete strip that runs along the entire perimeter of the building, as well as under the load-bearing walls. It is equipped by digging a pit. This type of foundation is optimal for the construction of an aerated concrete house.

The shallow version is ideal for constructing a building from aerated concrete blocks on an ideal soil that is not prone to heaving and shifts. The sufficient depth is 500 mm. In the opposite case, a strip type of deep foundation is being erected. The sole of the base will thus be below the freezing level.

A brick foundation will also be a good option for an aerated concrete house, but only if the soil is not prone to heaving, as well as during the construction of a one-story building.

Such a foundation is built only on stable soils with an even relief. The structure is a reinforced concrete grillage, at each corner of which and under the load-bearing walls, brick, stone or concrete pillars are installed. They can be round or square.

One of the types of columnar foundations for the construction of houses from aerated concrete blocks - the foundation according to the TISE technology - is the technology of individual construction and ecology. TISE differs from standard columnar foundations by the presence of a heel, which increases the area of ​​support of the column, while reducing the volume of pressure per square centimeter of soil, thereby almost doubling the bearing capacity of the pile.

TISE is a type of foundation that does not require special equipment during construction; for installation, you only need a TISE drill and portable formwork. One of the main requirements of the TISE technologist when erecting a structure is the lightness of the material. Therefore, the option of using aerated concrete is ideal here. Only if the rules are observed, a house built according to TISE will serve its owners for many years. Firstly, when developing a project, keep in mind that aerated concrete blocks do not like movement; it is also advisable to strengthen the concrete grillage, which will connect the piles with a single monolithic slab. Secondly, before erecting the walls, make sure that the base is stable and ready for further construction. It is recommended to make the foundation before the fall, and in the spring, after checking the geometry, start building the house.

When choosing which foundation to lay for an aerated concrete house, consider not only the economic benefit, since the final durability of the base, as well as the entire building, depends on many factors.

Assess the soil in your area.

For example, a reinforced concrete slab is the best option, since it minimizes shrinkage deformations.When the soil moves, the slab moves with it, ensuring the safety of the house. Slab foundations are able to withstand even the most aggressive climatic conditions.

The tape shallow version is suitable for houses standing on slightly or medium-grained soils. And the base deepened to the depth of freezing can be placed on heaving soils.

The columnar type of foundation is built only on stable soils with a flat surface.

In turn, the pile foundation is suitable for any type of soil, even for clay.

Also, experts advise taking into account the number of storeys of the building, since depending on the number of floors, the total mass of the building increases and, accordingly, the load on the base. If you have chosen a one-story house, then feel free to choose any of the foundations listed above. But it is recommended to build a two-story one only on a slab monolithic or tape basis. In this case, the depth and width of the tape in the latter version should be greater than when erecting a one-story building.

Before calculating, you need to know:

• density and thickness of gas blocks;
• approximate weight of building materials and roof;
• number of storeys of the building;
• type of soil;
• approximate snow load.

The design process includes not only drawing up drawings, but also the development of basic communication details, design of a basement or garage in the basement, drawing up a wiring diagram, etc. After all, all these factors directly affect the choice of the type of foundation for future construction.

Do-it-yourself foundation erection is possible, but it requires strict adherence to construction technology. Each type of foundation has its own step-by-step installation system.

As mentioned above, a slab foundation is perfect for aerated concrete houses. A foundation slab can last up to 100 years with a competent approach to construction. The basis of reliability is correct reinforcement with reinforcing bars with a diameter of at least 12 mm. You should not save on materials, since it is the metal frame that works in tension and will not allow the slab to crack in the future.

A reinforced concrete slab is installed under the entire surface of the house. The parameters of the slab should be based on the project of the future aerated concrete building. For example, for garages or baths, the minimum thickness is 100 mm, and for a residential building - at least 200-250 mm. When erecting, be sure to pay attention to the waterproofing of the slab: in the lower part, the base is waterproofed with roll materials, and the upper one - with coating or sprayed materials.

The main material of the strip foundation is concrete made from sand, cement and water. For better strength, it is necessary to strengthen the structure of the concrete base with iron reinforcement. Before construction, you need to clear the area of ​​the proposed construction site and make the necessary markings for all load-bearing walls. Next, the differences in the surface are studied and the lowest point is selected, thus eliminating the difference in the height of the foundation. You can dig a trench, the bottom of which should be perfectly flat, with your own hands or with the help of special machines. Next, a special cushion made of sand and gravel is placed on the bottom.

For pouring, it is recommended to use factory concrete, which is poured into the bottom of the trench in layers of 20 cm. Each layer must be tamped to avoid the formation of voids. The surface must be leveled after completion of work.

The strip foundation must be thoroughly dry before starting the construction of the walls. This may take about one month.

The pile and columnar options are considered the most economical due to the low consumption of materials, as well as the high speed of construction.

From above, both types are connected by an iron horizontal grillage, on which the building is then built.

Before laying the first row of blocks, it is necessary to carry out waterproofing work for the foundation. As a material for waterproofing, you can choose roofing material or polymer - cement mortar based on dry mixes. It is necessary to carefully level the base with a cement-sand mixture.

It is worth paying special attention to the laying of the first row of aerated concrete blocks, because the quality of the entire building will depend on how smoothly they are laid. The evenness of the masonry can be determined using a cord and a level.

For styling, a special glue of the consistency of thick sour cream is used. The glue solution is applied with a trowel or carriage, the width of which should be equal to the width of the masonry.

• The best option for a slab base for an aerated concrete house is an insulated slab, which provides the necessary stability of the floor.
• The production of work using aerated concrete blocks must be carried out at temperatures from +5 to +25 degrees.
• To prepare the concrete mix for the strip foundation, it is recommended to use clean water, and sand without any admixture of clay and earth.
• If the outside temperature is below zero, then it is allowed to use warm water for mixing the concrete solution, while in the heat, only cold water should be used.
• Carrying out work on the construction of the foundation in unstable soils, it is worth taking care of the strengthening of the walls of the pit.
• Concrete grade M100 is suitable for the initial stages of construction and concrete pouring. M200 is used for building foundations for houses with light overlap, M250 and 300 are perfect for building foundations for bulky private houses.

• In order to strengthen the columnar foundation, it is necessary to strengthen its supporting area. The strip base is reinforced with topping up with reinforcement, piled with reinforced concrete clips along the entire length of the pile.
• The basement will increase the usable area of ​​the dwelling up to two times, but a residential basement floor is impossible without high-quality waterproofing.
• To prevent the walls of gas blocks from cracking ahead of time, it is necessary to reinforce them, and then expose the blocks to external finishing.
• Plan the time of building the walls of the house, taking into account that the stage of building the foundation takes about a month of work.
• Remember that you should not start building a foundation without calculating its total cost in full. The cheapest option for the foundation for a private house is considered to be a pile.

For information on what foundation is needed for a house made of aerated concrete, see the next video.