Residential houses made of foam concrete blocks are very popular in modern construction, as they have excellent thermal insulation characteristics, and their construction requires little cost. In order for such a building to last reliably for many years, at the planning stage it is necessary to first select the appropriate type of foundation.
The foundation for houses made of foam blocks can be different, and its choice depends on many factors, so before laying the foundation it is important to do all the calculations correctly and carefully study the features of the land.
The foam block is considered a good material for housing construction, but its main drawback is its high hygroscopicity and tendency to deformation. If this feature is not taken into account in the choice of foundation, then over time houses from foam blocks can undergo destruction.
To minimize the risk of cracking in the walls of the building, it is necessary to provide a foundation with high-quality waterproofing, especially for buildings whose sole is located below the level of soil movement. Most often, a “floating” foundation is chosen for such houses; it is inexpensive and absorbs soil movements excellently. In addition, you need to further increase the height of the "pillow" to 50 cm.
When installing the base under a foam block house, you should also perform high-quality filling, consisting of several layers of sand. It is aligned horizontally using a hydraulic level and carefully compacted with rollers.
A huge role in the foundation is played by waterproofing , therefore, before the formation of a sandy “pillow”, trenches are covered with roofing sheets, and the seams are coated with bitumen. In the event that on the territory of the land plot where the construction takes place, groundwater is located close to the surface of the soil, it is necessary to lay drainage pipes.
Before deciding on the type of foundation, you must also consider the following nuances:
- relief feature;
- soil condition;
- construction terms;
- work budget.
In this case, special attention must be paid to the general parameters of the future home. This primarily concerns the number of storeys, the size of the rooms, the location of doors, windows and the type of roof structure. The massiveness of the structure and the features of the foundation will depend on the above indicators.
Any construction begins with design, and the foundation is not an exception to this. For a house of foam blocks, the foundation needs a strong and reliable. Regardless of whether it is planned to build a one-story or two-story house, the foundation is laid with a preliminary assessment of the soil. To do this, study the uniformity of the layers, the strength of the soil and its tendency to shrink, then the drawings of the building itself are introduced into the project.
For the construction of houses on clay soil and quicksand it is important to provide special protection and lay a good waterproofing. Of course, foam blocks are best installed on stable soil, but most of the plots are placed on clay, so their development requires a special assessment of the soil and proper installation of the foundation, as the slightest inaccuracy will affect the operation of the building.
Design also depends on the level of groundwater : if they are located next to the soil, the structure can be flooded and the soil will sag, which will lead to corrosion of the foundation.
If the dimensions of the house are small (6x6 m), then shallow depth is suitable for the construction of the foundation, buildings on 2 floors are heavy, so they are erected on a deep-lying foundation that can withstand significant loads. The design should also include the weight of the finishing material.
The walls in the houses can be made of brick, concrete, or sheathed with wood. In addition, large buildings with a size of 10x10 m are often supplemented with an attic and columns, in connection with this, the load on the base increases and must be correctly calculated.
After all of the above factors are taken into account, the foundation is designed, and the direct construction begins. Drawings can be prepared both independently and use the services of specialists.
Before you build a base for the house from foam blocks, you need to not only correctly design the project, but also accurately calculate all the sizes and consumption of the material. A huge role in the calculation is played by the mass of all structures, as well as the width, depth and area of the ground , therefore, first of all, the weight of the future home is determined, and only then the area of the base is calculated. This indicator depends on the type of structure and is calculated by multiplying the width by the length of the foundation. To choose the optimal depth for the base, you should take into account the level of freezing of the soil.
If the sole is placed on rocky soil, then make a depth of 0.5 m, for soil with a low coefficient of freezing, the height should not exceed 1 m.
An important role in the construction of the foundation will also be played by the calculation of the materials themselves. Before laying, it is necessary to determine the amount of reinforcement, concrete and piles. This will help to avoid unnecessary costs, and reduce the time of building a house. The volume of concrete mix is calculated simply: the area of the foundation is multiplied by its height.
As for the number of fittings, with its calculations it is much more difficult, since they depend on the weight of the building, the type of soil and the type of foundation. The heavier the structure, the thicker the reinforcement will be needed. As a rule, ribbed or smooth reinforcement is used to install the foundation. In this case, the latter is required 2 times less, since it is taken at the rate of 30 cm per connection. To determine the number of piles, the area of the base is divided into the cross section of one pile, the result is the total number of piles.
How to make?
The foam block is a durable, lightweight and reliable material for construction, which is made from cellular concrete. Therefore, houses built from a foam block are characterized by a small static load, and for them you can choose lightweight foundation options. The foundation for the construction can be laid with your own hands. In order for the work to be done correctly, it is important to follow all stages of the installation step by step and adhere to a certain sequence. Laying the foundation varies depending on its type.
First, you need to dig a trench with a depth of not more than 50 cm. Digging should be done both under future load-bearing walls, and around the perimeter of the house. The base is made according to preliminary calculations, and it should be 10 cm wider than the walls.
A sand cushion is placed at the bottom of the trench and is additionally covered with gravel. The thickness of each layer is approximately 10 mm. After the pillow is carefully tamped, the formwork is prepared and the reinforcing cage is installed. For the frame, it is best to use rods with a diameter of 10 mm. Then the trench should be poured with concrete, the solution is evenly distributed over the entire working area. In the event that construction is carried out in the summer, the concrete dries quickly. To prevent cracking, the surface should be periodically watered and covered with a film.
As a rule, the construction of a house can begin 10 days after the foundation has completely dried up , the foundation during this period of time becomes strong and is ready to withstand the load of the structure. If the groundwater level is high, then the foundation should be protected from flooding. On the inner side of the formwork, the waterproofing is fixed in the form of a hydroglass glass or roofing material and give the formwork additional time for solidification.
The foundation with waterproofing is considered ready after a month.
This type of foundation is chosen in the case when a foam block house is built on weak soil, consisting of loam, peat and clay. Such a foundation reliably protects the structure from freezing and heaving of soils. The pillars for the base are selected from reinforced concrete, they need to be laid at the locations of large loads , load-bearing walls and corners of the facade. The pillars are buried in a depth of 1 m at a distance of 1.5-2 m.
For houses, the number of floors of which is 3, the columnar foundation is additionally reinforced with special reinforced concrete grilles. The formwork in this case is distinguished by a bottom, which is supported by supports installed in the ground. After the formwork is ready, the reinforcing cage is attached to it with the help of knitting wire and mounting loops.
For work, it is best to use rods with a diameter of 8 mm, and for pouring choose concrete grade M 200.
Such a foundation is suitable for all types of soil, with the exception of only clay. The base is a monolithic slab, which can be moved together with the soil, protecting the walls of the structure from damage and cracks.
To make such a foundation, you must first dig a pit with a depth of at least 60 cm under the entire area of the building, then lay a pillow consisting of a layer of sand (25 cm) and crushed stone (15 cm). After that, a reinforcing frame and waterproofing are sure to be arranged. For the frame, rods with a diameter of 8 cm are used and a pitch of 25 cm is observed between them.
As for the foundation for houses in the design of which a basement is provided, it requires special implementation technologies. The main feature of such a foundation will be depth, therefore a deep foundation pit is dug for laying and along the perimeter of the foundation they create a space that will press on the walls with the thickness of the soil outside.
The evenness of the trench must be checked with a laser level, after which gravel, sand can be filled up and waterproofing laid. Formwork is installed on the walls of the trench, it can be made of any building material: polymer, metal or asbestos pipes.
The outer part of the formwork must be fixed with screeds or slopes.
Inside the formwork, a metal belt of rods with a diameter of 16 mm is mounted for reinforcement. The result is a structure resembling a cell; its walls should not touch the upper surface and the bottom of the future fill. The rods of the frame must be overlapped, and bend in the corner sections of the foundation without stirring. It is best to fix the frame using electric welding or knitting wire. The final stage of work will be the pouring of the solution, it must be carried out in layers. After each filling of the layer, the surface is leveled.
In addition, screw piles are often used as supports for the foundation, which are screwed into the soil below the level of freezing of the soil. The installation of piles must be performed accurately, therefore, the correctness of their fixation is checked by the laser level. After the piles are twisted, concrete is poured into the inner part of the pipes, and the upper part is closed with heads.
The construction of a foam block house must begin with the design and selection of the type of foundation, on which the strength and life of the building will depend. If the laying of the foundation is carried out independently, then the advice of experienced specialists will help the beginning masters in this.
- Before installing the foundation, it is necessary to examine the soil of the site. To do this, a 2.5 m deep well is pre-excavated, soil samples are taken and their composition is revealed. Depending on this, the type of foundation is determined. For areas with weak soil, it is best to choose a strip foundation.
- Great attention should be paid to the depth of freezing of the soil, as a rule, it is from 1 to 2 m.
- For areas where the groundwater level passes near the soil, it is advisable to build monolithic slabs. This will be the cheapest option, since when laying the strip foundation, you will additionally need a drainage system and waterproofing, which will entail significant costs for the purchase of material, and slow down the construction process.
- The foundation design should be made taking into account additional extensions to the house, as well as the presence or absence of a basement. Most of the country houses in their layout have basements, so for them it is necessary to choose strip foundations and worry about quality drainage.
- If you need to quickly and inexpensively establish a foundation, then the pile foundation will be the best choice, monolithic slabs are considered expensive, so their installation will require a lot of costs.
- Laying the foundation for a foam block house can be done both with the help of specialists, and independently. Moreover, the latter option will save money and individually plan the stage of work. In order to establish the foundation with your own hands, it is not necessary to have special skills, it is enough to properly prepare the project and calculate all the parameters. Thanks to simple formulas, you can quickly calculate the consumption of material and slowly perform a quality installation.
- Foam houses are recommended to be built low, since structures exceeding 3 floors will require additional reinforcement of the foundation, and this, in turn, will complicate the construction process.
About how to build a house from foam blocks with your own hands, see the next video.