The device of plate Foundation
Slab Foundation is a modernized version of strip Foundation, which is famous for its reliability and high carrying capacity. Slab Foundation is a solid reinforced concrete slab, shallow in the soil.
Device slab Foundation includes the following "layer":
- A layer of geotextile, laid in the excavated pit under the Foundation
- A drainage layer of sand and gravel
- Insulation (it is recommended to use Styrofoam)
- Reinforcement mesh
- Concrete screed
- Waterproofing basement
It should be noted, what is wire mesh and concrete screed some gardeners use a ready-made reinforced concrete slabs. Several plates are stacked in the pit, and over them is poured a small concrete screed. This option is not recommended, because. in this case, the strength of the Foundation is much smaller because of the heterogeneity of design.
Advantages of slab Foundation
Advantages of slab Foundation are:
- Higher bearing capacity of the structure
- The simplicity of construction of the Foundation (difficulties may only arise in calculations)
- The Foundation slab is slightly deepened, therefore, almost not subject to deformation during freezing/thawing of the soil
- The Foundation slab can be used as a finished floor, the important thing to heat-insulate it
- The construction of a slab Foundation is a minimum of ground works
- It is advisable to apply on difficult soils
Despite this, we have said, monetary cost of building materials during the construction of the Foundation slab are high, so to use this type of beam is only recommended for difficult soils and for the construction of lightweight structures (amenities, summer kitchen, baths).
Calculation of slab Foundation
The most difficult stage in building a slab Foundation with his own hands is his calculation. It really is as, because if the operation is wrong slab Foundation, you either overpay money, creating a too solid construction, or saving money, over time you will see the distortions of the walls on the garden building, tile is installed on the Foundation.
The calculation of the slab Foundation is not too complicated. The main thing that you should know: bearing capacity of soil and bearing capacity of concrete. In order, to ensure that, what tile will the Foundation bear the weight of buildings, it is necessary to divide the total weight (Foundation+building) in the area of the basement.
For example, the bearing capacity of dry soil is 2 kg/cm2 , and the carrying capacity of concrete grade М510 is about 150 kg/cm2. Based on this, the pressure of the Foundation with a building must not exceed 2kg/cm2. Only in this case the construction will not deform over time.
What would you have understood the essence of the calculation slab Foundation, bring to your attention an example.
We want to build a two-story bath, size 10*10 m. Based on this, the area of the basement is equal to 100 m2. Now calculate the weight of the Foundation. If its thickness is 20 cm, the approximate weight (given the reinforced layer) will be about 100 tons. The total weight of the two-storey bath with a wall thickness of 25 cm will be about 130 tons. Just keep in mind the weight of the furniture, people and other objects in the house, to calculate 70 tons (because. bath two-storey). Total, the weight of the Foundation construction is 300 tons. Accordingly, 300 tons/ 100 m2 will be pressure on the ground 0,3 kg/cm2, what is enough to ensure normal functioning of the Foundation.
Please note that, what is most needed for the calculations of the data to be in the Standards, SNiP and other standards.
It is important to note, what is the minimum thickness of the slab Foundation should be 20 cm, and the maximum 30 cm (excluding the height of ribs).
It should be noted, calculating the slab of the Foundation is better to pass into the hands of professionals, which will carefully analyze the properties of soils, climatic conditions and features of the buildings. Although for this you will have to pay some money, but the way you will definitely save money on materials and be sure, the Foundation does not crack through a season or two!
Construction technology slab Foundation with his own hands
In order, that would be to build a slab Foundation, you must do the calculation, to knock out the estimate and prepare the soil.
Further, the construction of the slab Foundation will include the following stages:
- Dig the pit depth of not more 50 cm
- Paved drainage bed of gravel and sand (20 cm), fill with water and carefully stamped
- Install the formwork and laid in her dressing fittings from (use rods with a thickness of not less than 12 mm)
- Concrete mortar thickness 20-25 cm
- Do a concrete deck around the perimeter of the building
- We carry out basement waterproofing with molten bitumen mastic and roofing material
- Insulate the Foundation penopropilena plates
That's the whole technology of the construction of the slab Foundation with his own hands! Recommended to read video example of creating this type of bearing structure:
Also check out our article: create a pile Foundation with his own hands!