Foundation for a house made of aerated concrete on 2 floors: which one is better to choose, how to calculate and build

For a two-story aerated concrete house to be stable and long-lasting, the foundation must be chosen carefully. Given its reputation for being both lightweight and durable, aerated concrete needs a foundation that can sustain its weight over time.

A two-story structure’s unique load-bearing requirements, the local climate, and the state of the soil all play a role in choosing the type of foundation. Depending on the features of the site, common options include pile, raft, and strip foundations, each of which has unique advantages.

Carefully calculating the weight of the house, the soil bearing capacity, and any potential differential settlement is necessary to determine the best foundation. During this process, structural engineers or architects are consulted in order to evaluate the necessary structural components and suggest the best foundation design.

The construction process starts with site preparation, excavation, and making sure the right reinforcement and formwork are in place once the type of foundation is selected. Careful attention to detail is necessary when building an aerated concrete house’s foundation in order to guarantee the structure’s stability and resistance to environmental influences and ground movement.

Foundation Type	Advantages and Considerations
Strip Foundation	Common choice for stability and cost-effectiveness. Requires accurate calculations for load-bearing capacity and settlement prevention.
Pile-Grillage Foundation	Suitable for uneven terrain and offers better load distribution. Requires deeper excavation and higher construction costs.

Requirements for foundations for a two-story building

An ideal masonry material for building a two-story home is aerated block. Cellular concrete blocks have a low specific gravity and excellent thermal insulation.

The following information is used to choose and compute a supporting structure:

• type of soil base;
• ground water level;
• soil freezing depth;
• specific load from the building.

The foundation must allow for a settlement of no more than 2 mm per meter in order for it to be stiff and shield the structure from movement. If built on a site with stable soil and low groundwater levels, or if the foundation is deep enough, it will satisfy these specifications.

Soil type on site

The resistivity of the soil is determined by its structure. It needs to be more than the particular load resulting from the total weight of the house. Soils can be divided into 5 major groups:

• Rocky ground the strongest foundation for a multi-story building.
• Gristly soil, saturated with gravel, stone fragments, not subject to heaving, able to withstand heavy loads from buildings.
• sandy soil always remains dry and does not swell, may sag a little under load – refers to reliable foundations.
• Loam, representing a transitional structure from sandy to clay soil, will withstand any type of foundation.
• Clay and marshy soils belong to the most unreliable heaving soil foundations and are suitable only for the construction of pile foundations.

Pay heed. A copy of a vertical survey conducted at the department of architecture and land management construction site can be used to determine the composition of the soil. In a different situation, they contact geological services, who will drill holes to collect soil samples and determine the groundwater table.

Groundwater level and freezing depth

Measuring the water level in a nearby well in relation to the ground surface is the simplest method for figuring out the groundwater level. As previously mentioned, vertical surveying is used to determine the parameter in any other case with respect to the location of future construction.

Soil heaving is caused by a change in the amount of moisture crystallization in the soil during the winter months. The parameter is found in regulatory documents or through experimental drilling conducted in the winter.

Specific load

The specific load is the weight of the entire building on one square meter of the base. This parameter has a significant impact on the foundation type selection.

The minimum supporting area of the foundation base is determined by comparing the specific load resulting from the house’s weight with the soil resistance. The choice of the building’s strip, column, or pile foundation is then made.

Kinds

Strip, pile, columnar, and slab foundations are built for homes composed of aerated blocks, contingent on the soil foundation’s conditions.

Tape

These kinds of foundations have long, closed plans. They are built in preparation for later load-bearing partitions and walls. In addition to prefabricated reinforced concrete, rubble stone or other masonry materials are also utilized to form the tape.

If the freezing point of the soil is less than one meter, then a shallow foundation should be built. Although this design is the most cost-effective, it takes a lot of time to set up the formwork, add reinforcement, pour concrete, and harden it. A monolithic strip is also only constructed during the warm season. Although a reinforced concrete block foundation will cost more, the developer will save a significant amount of time.

With caution. Soils that are weak and peaty have low resistance. The strip structure on such foundations will eventually bow under load and eventually collapse.

Columnar

Imagine this kind of foundation as a torn monolithic strip that has been broken into individual supporting pieces (pillars).

Compared to the house’s strip foundation, this preserves the supporting structure’s load-bearing capacity while resulting in significant material savings.

A multitude of materials are used to construct pillars. Brick, wild stone, and rubble stone are also used as columnar supports in addition to monolithic reinforced concrete.

Using sections of metal or asbestos pipes as permanent formwork and lowering them into the pits to create spaces for reinforced frames and concrete filling is an intriguing alternative.

Pile

When it’s necessary to move weight through weak clay soil and from the foundation to layers of load-bearing soil, piles are utilized. The impact method is used to install the supports. employing a hand hammer. Kopov defines a mechanized method as using piles.

A variety of supports made of different materials are called piles. It could be wooden piles, metal, reinforced concrete, or even brownish.

Regarding a note. Screw piles are an interesting kind of support. In the shortest amount of time, you can manually create a support base.

These days, a lot of developers say this is among the greatest choices for an aerated concrete foundation for a two-story home.

Plate

Slate bases are built on clay and marshy soils, which are considered weak ground. Soil is typically removed under slab foundations with a maximum thickness of 500 mm. Armic cards are positioned inside and concrete is poured after forming shields are put in place around the outside. The design resembles a large bearing capacity floating plate.

Criterias of choice

Strip foundations are the best option for two-story aerated concrete homes with small floor plans (6 x 4 m and 4 x 4 m).

The overall cost of construction in this instance is not significantly influenced by material consumption.

Furthermore, as the tape will need a lot more concrete and reinforcement, it is preferable to create a pile support for a building with a plan size of 10 by 10 meters.

Calculation of dimensions

There is a specific method for determining the structure’s dimensions for every kind of foundation:

1. Tape. Here the length, width and height of the base are calculated:
2. the length of the tape is equal to the length of the perimeter of the load-bearing walls;
3. the width of the monolithic strip is determined by calculation, where the weight of the building is correlated with the resistivity of the soil base. The result is the total supporting area, which is divided by the length of the perimeter – the minimum width of the foundation should be 50 mm greater than the thickness of the load-bearing walls on each side;
4. the height of the tape is determined by the sum of two values ​​- the depth of the base and the height of the base – the first parameter is entirely tied to the depth of soil freezing – the base should be below it and above the groundwater level.
5. Columnar. For it, the supporting area and height of the supports are calculated:
6. the supporting area is calculated in the same way as in the previous case – it is divided by the number of supports, based on the fact that the minimum distance between the pillars should not be less than 1.5 m; this gives the size of the pillar in plan;
7. the height is determined by adding the estimated depth of the base of the pillar below the soil freezing level and the vertical size of its ground part.
8. Pile. The load and number of piles, the length of the supports, and the depth of the bearing layer are determined:
9. The total weight of a house made of aerated blocks, including the snow load, is theoretically determined, and the resulting value is divided by the area of ​​the building – the load per 1 m2 is obtained; in case of unforeseen circumstances, the reliability coefficient k = 1.1 is taken into account;
10. taking into account the minimum distance between piles of 1.5 m, calculate the optimal number of supports;
11. the length of the pile is determined based on the depth of the load-bearing soil layers;
12. the depth of the bearing layer is determined in two ways – by experimental drilling at the construction site followed by testing soil samples in the laboratory or by taking reference data from the local architecture department.
13. Slab. The calculation of a slab foundation is that its area is determined by the size of the house in plan + a blind area 1 – 1.5 m wide around the perimeter of the building. Practice shows that for a 2-storey house made of aerated blocks, the thickness of the foundation slab should not exceed 300 – 400 mm. To calculate reinforcement, you can use an online calculator.

How to build a supporting structure with your own hands?

They create their unique set of detailed instructions for every kind of foundation. You can use the options below to get step-by-step instructions for building the following foundations by hand:.

Stick:

1. According to the developed plan, markings are applied at the construction site using a cord, pegs and a level.
2. Along the stretched cord, trenches are dug slightly wider than the calculated size and 100 mm below the calculated depth of the base.
3. The bottom of the ditches is covered with sand, followed by compaction with a thickness of 100 mm.
4. Formwork panels are installed on the sides of the trenches.
5. PVC film or geotextile is laid at the bottom of the ditches, the sides of which are placed on the wooden walls of the formwork, securing them with a stapler or nails.
6. Lay reinforced frames and tie them together with wire.
7. The formwork is poured with concrete.
8. After 30 days the formwork is dismantled. The foundation is ready for use.

See this page for more information on creating a strip foundation correctly using your hands.

Columnar:

1. Markings are applied according to the project.
2. Digging pits.
3. The bottom is covered with film.
4. Sheets of formwork are installed on the sides of the pits.
5. Reinforced frames are lowered into the formwork and filled with concrete.
6. After 30 days, further construction begins.

Here is more information on how to construct a columnar foundation by hand.

Pile:

1. At the construction site, markings are made of the places where the supports will be.
2. Piles are driven into the designated locations.
3. The heads are aligned horizontally.
4. The grillage is used to unite all the piles into a single supporting structure.

See this article for more information on creating a pile foundation by hand.

Slab:

1. The same actions are performed as when constructing a strip foundation.
2. The peculiarity is that after pouring concrete, the slab must be protected with a film, both from drying out in hot weather and from over-moistening during rains.

The foundation of a two-story aerated concrete house is an important decision. This article examines various foundation types appropriate for these kinds of structures, guiding your decision-making process based on elements such as building weight and soil conditions. It provides helpful guidance on determining the load-bearing requirements and helpful construction advice. Whether you’re thinking about raft foundations, strip foundations, or something else entirely, this guide makes it easier to understand the process and guarantees that your house is built on a solid foundation that is suited to the unique requirements of aerated concrete construction.

Common mistakes and recommendations

When building supporting structures, common errors include the following:

• Liquid concrete is poured into the formwork on open ground. Part of the “milk” will leave the solution into the soil. This can lead to the loss of a significant part of the bearing capacity of the monolith and the appearance of cracks. To avoid this, the soil must be covered with a film.
• On weak soils, a strip foundation is installed, which will sag and collapse over time. You should choose the type of foundation based on the advice of experts.
• Driving piles manually can lead to deviation of the supports from the vertical, which will lead to a decrease in their load-bearing capacity. When installing piles you need to use a laser theodolite.
• Without experience in construction, it is better not to undertake to build the foundation yourself. You need to contact specialists who will carry out the necessary work with a guarantee.

For a two-story aerated concrete house to be stable and long-lasting, the foundation must be chosen carefully. Given its reputation for being both lightweight and durable, aerated concrete needs a foundation that can disperse its weight uniformly throughout the soil. Strip foundations and pile foundations are the two primary foundation types appropriate for these kinds of structures.

For structures like two-story houses with evenly distributed loads, strip foundations are frequently utilized. By distributing the weight of the structure over a larger area, they offer a sturdy foundation. The size of a strip foundation is determined by taking into account the local building codes, the type of soil, and the dimensions of the building. Excavation, reinforcement installation if necessary, and concrete pouring to the necessary depth and width are all necessary steps in the proper construction of a strip foundation.

Conversely, places with unstable soil or high water tables are perfect for pile foundations. Via vertical piles that can be driven or bored into the ground, they disperse the weight of the building farther below the surface. A few examples of these variables are the weight of the structure and the state of the soil. In order to prevent settlement and distribute weight evenly, pile foundations work well.

It is crucial to carry out a comprehensive soil analysis and confer with a structural engineer or builder prior to selecting the type of foundation. When choosing the best foundation for your aerated concrete home, factors like soil bearing capacity, groundwater levels, and local climate conditions are important considerations. You can guarantee the structural soundness and longevity of your two-story home by selecting the appropriate foundation and making sure it is built in accordance with local codes and best practices.

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