The thickness of the monolithic plate of the foundation for aerated concrete house

An important consideration when building a house with aerated concrete is the foundation. The strength of your home’s foundation has a major impact on its stability, longevity, and strength. A monolithic concrete slab is a popular option for this kind of foundation.

This monolithic slab’s thickness is crucial in guaranteeing that the house can sustain its weight and endure a variety of environmental conditions. A number of important considerations must be made in order to determine the proper thickness, such as the type of soil, the load-bearing requirements, and local building codes.

We’ll look at the key factors that determine the perfect thickness for an aerated concrete house’s monolithic slab foundation in this article. We’ll assist you in making defensible decisions for your construction project by dissecting the technical details into clear, concise concepts.

The thickness of the monolithic foundation plate is critical to the stability and longevity of an aerated concrete home. A well-thought-out foundation plate, usually with a thickness of 20 to 30 centimeters, guarantees that the house can support the weight and adjust to ground movements. This thickness is essential to the longevity and safety of the structure because it strikes a balance between strength and cost-effectiveness.

Description of a monolithic slab and technical characteristics

A monolithic base is a plate of reinforced concrete whose shape matches the arrangement of the house’s exterior walls.

Schematically, this structure’s internal device in this context appears like this:

1. Pit. Equipped in all cases, regardless of the depth of the supporting system. Designed to place all its elements.
2. Drainage canvas. It is laid on the bottom of the pit to prevent the erosion of shock spraying.
3. Pillow. It is made of sand and crushed stone. The thickness varies within 30-50 cm, depending on the type of soil and the mass of knowledge.
4. Insulating layer. As a rule, a combination of roofing felt and foam boards is made. Protects concrete from cold, moisture and active chemical compounds in the ground.
5. Steel frame. Serves to bear tensile, compressive, torsional and bending loads. Prevents the appearance of cracks, ensures uniform distribution of the weight of the building over the entire area and transfers it to the ground.
6. Concrete. For filling, a mixture of grade M300 and higher is used. The thickness of the concrete slab is calculated in each case separately, taking into account the conditions accompanying the task being performed. The minimum thickness of the concrete slab is 20 cm for aerated concrete buildings and 30 cm for bricks.

It is recommended that the floating base be lowered to the pillow’s thickness plus an additional 3–5 cm for the slab. Sinking the foundation any further is not worth it because melt and storm water can flood it, which is very bad for the walls.

Slab bases can have stiffening ribs or be flat, depending on the lower plane’s shape. The latter are employed in the building of multistory buildings and in soft soil.

A base is constructed when the first level’s height is insufficient to produce a layer of thermal insulation. In order to be able to set up a technical floor in the area between the slabs to accommodate devices for communications, heating, water supply, and filtration, it is advised to build it no lower than 150 cm.

What affects the calculation of the thickness of a monolithic foundation slab

A two-story house built with aerated concrete blocks can have its foundation slab thickness determined by comparing the following information:

• Building weight. Consists of materials from walls, ceilings, windows, doors, furniture and household appliances.
• Soil type. Its density, degree of heaving, levels of alkali and acid content are determined. Freezing depth is not taken into account.
• Soil moisture and groundwater depth. Determines the likelihood of subsidence and deformation of the soil, erosion of the foundation base.
• Average and maximum winter temperatures, the need to use insulation and its type.
• Soil bearing capacity. Defined in tons per unit area. If these indicators are low, the monolithic reinforced concrete slab may be larger than the walls of the building.

The area and thickness of the floor are computed after all the data have been compared.

Minimum thickness

Although foam concrete is lightweight and porous, the completed structure places a noticeable load on the supporting system. The weight of the floors, large windows, doors, and a fairly substantial roofing system are added to the blocks’ weight.

Conversely, loads from heaving, swelling, and shrinking soil with variations in soil moisture have an impact on the support system. As a result, a floating slab has an effect when it rises and falls in time with the soil’s deformation.

The analysis of these variables reveals that the force of twisting and bending serves as the primary criterion for determining the base’s parameters. In order to combat this, a house built with aerated concrete needs a monolithic foundation slab that is at least 20 cm thick if only one floor is being built, and an extra 5 cm for each additional floor or attic. Because of the disparity in area loads, a thin slab will simply crack, and a heavier base will result in unnecessary expenses.

Necessity of calculation

You should consider the characteristics of this material when planning to build a house out of aerated blocks. Its smooth edges, high thermal insulation values, and low specific gravity all help to create clean, well-kept masonry. The blocks are extremely brittle, though. The foam concrete wall cracks if the reinforced concrete slab bends. Furthermore, keep in mind that the material requires external finishing because it is hygroscopic.

The requirements for a foam concrete house’s foundation are determined by the factors mentioned above:

• Sufficient strength to withstand vertical pressure from house structures.
• Resistant to bending and torsional loads that come from unstable soil.
• Low thermal conductivity, if you do not plan to build a basement level. Use of drainage, heat and waterproofing.
• Long service life. Houses made of foam concrete are designed to last 60-75 years, the support system must correspond to it.
• Stability in space. To do this, the slab is slightly recessed, and for additional stability it is equipped with stiffeners.
• Sufficient area. On particularly unstable soils, it is advisable to extend the edges of the slab 100-120 cm beyond the external walls. This helps reduce pressure on the soil and eliminate the risk of subsidence. In addition, the protruding part of the foundation will act as a blind area. This strip of concrete gives the building a finished look, protects it from dirt and water, and can be used as a pedestrian path and parking for small wheeled vehicles.

The minimum strength standards should not be used as a guide when designing a slab-type support structure. It is advisable to leave a 5-cm margin, as this might be necessary in the future when adding more stories to the building.

For an aerated concrete house to be stable and last a long time, the thickness of the monolithic slab foundation must be chosen carefully. The weight of the house, the local climate, and the state of the soil all have a major influence on thickness. For most residential buildings, a thickness of between 200 and 300 mm is typical, offering a sturdy and dependable foundation.

Selecting the right thickness helps with cost management as well as ensuring structural integrity. Although thicker slabs may be more stable, they come at a higher cost in terms of labor and materials. Finding a balance that guarantees safety without incurring needless costs is crucial.

The ideal slab thickness for your particular project will depend on careful planning and structural engineer consultation. This customized strategy ensures that your aerated concrete home will endure for many years by resolving particular site issues.

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