Strip foundation - this is one of the most common types of foundation for the house, but he is not without a number of drawbacks.For example, if you forget to make a strip foundation produhi (or incorrectly calculate their cross-section), then over time it can lead to problems.Due to the lack of ventilation underground wooden logs are covered with fungus, mold and rot.Excess moisture in the basement also leads to the destruction of the concrete floor slab of the first floor.
To avoid this, you can replace the traditional air holes in the closed ventilated underground.This was detailed in the article "Do we need air holes in the basement?".But there is another option - to refuse to organize underground and strip foundation based on the ground floor, as the experts advise FORUMHOUSE.
What is on the ground floor?
floors on the ground is a monolithic concrete base (tie).Ties poured inside the perimeter strip foundation on well compacted soil, which is filled sinus foundation and a layer of insula
Razlichayutdva type on the ground floor:
1. On the prepared substrate (well compacted soil) is poured floor slab, rigidly connected with the strip foundation.
2. On prepared base floor slab is poured, unrelated to the strip foundation, the so-called "floating" screed.
Let's examine the pros and cons of these options.
- If you pour a "floating" screed, it thus "undone" construction tape and sex.If there is shrinkage, the screed "play" regardless of the basement, the design will not crack, becauseNo stress.That's a plus.But there is a minus - the floor "live your life" separate from all the other designs.
This can lead to small, but annoying defects - cracking tile appearance of a gap between the wall and the skirting.
When filling the rigid structure of the node "foundation / screed" works as a whole.The screed will not shrink becauseIt lies on a foundation.But if the ground under the floor is sealed well enough, after a while it can sag, and tie "hang" in the air.Under a heavy load, for example, if the screed are walls, partitions, support members, which may result in deformation of the base, fractures and loss of carrying capacity of the assembly.
Therefore both versions ties have both pluses and minuses.In each case, much depends on the quality of the soil and compacting the bulk of the proper structural elements on the ground floor.
- When filling a "floating" tie knot "of the foundation wall / screed" should really unleash, otherwise it may be pinched in the frame structure of the tape.Iefloor inside the frame with respect to the tape should move freely, otherwise lost all sense of floating screed.
To do this, between the screed and the foundation (the wall) is made of an elastic damping material regains its original shape after the load is removed.For example, izolona thickness of 8-10 mm.This will allow the concrete screed freely "float" and compensates for its thermal expansion.
common mistake - to link all components rigidly as possible.As a result, in the construction having increased load.In the case of floating screed elements of the "floor" and "foundation" operate independently of each other.
basic principles of the device on the ground floor
well prepared base - the key to a long life of the floor on the ground.Charging base (sand) must be carefully watered and ramming layers of 10-15 cm. To properly douplotnit base, you can use crushed stone backfill (gravel coarse fraction).Through filling rubble when driving on it tampers strike occurs locally, resulting in the deep layers of the soil underlying douplotnenie.
On the right method is to build up the ram sand attention.
- All instructions for the compactors says that cooker Rams sand to a depth of 20-30 cm., But that's just how well the layer is sealed?So I think that for reinsurance better ramming the sand layer of about 10 cm. It looks like this:
- throwing sand layer 10-15 cm.
- vibratory plates pass through the sand "dry."
- sand sheds water from a hose.This is best done no running water, so as not to break the layer and through the nozzle spray.
sheds water is necessary so that the sand was wet, but not oversaturated with moisture.If the water is too much, almost compacted sand.
- pass on the moist sand vibratory plates 2 times with the change of orientation of the movement.
- sheds sand with water again.
- pass on the moist sand vibratory plates More 2-3 times with the change of orientation of the movement.
After careful substrate preparation proceed to the installation of hydro- vapor barrier, which protects the floor structure from moisture.Often the question arises: whether it is necessary before laying this layer do footing?After weld or pasted waterproofing, to avoid damage to it, must be placed on a flat rigid base.
- Making footing for laying the waterproofing should be with the pressure of groundwater.This is true for basements.For the device on the ground floor is sufficient to use conventional polyethylene film.
The film thickness of 150 microns is placed on the prepared base with overlaps of 15-20 cm with a mandatory sizing joints.For safety film can be laid in 2 layers.
As a heater on the ground floor can be used polystyrene PSB-25 (foam) or extruded polystyrene.Minimum thickness of insulation - 100 mm.
foam, unlike Epps, afraid of direct contact with the cement-sand mortar.Therefore, a layer of expanded polystyrene before pouring the screed must be protected, lay on top of him, overlap, polyethylene film.
Then, on top of a heater, poured screed thickness of 50 mm.Screed reinforced, for example, a metal grid with 100x100 yacheёy rod diameter of 3-4 mm.
also at the device on the ground floor is necessary to properly insulate the foundation, blind area and divert water from the cap.Learn how to do it with their own hands, it can be made from this material.
Pros and cons on the ground floor
The advantages on the ground floor are:
- opportunity to devices on most types of soil;
- sincethe foundation of a well-insulated, it is resistant to the forces of frost heaving;
- smaller than conventional slab foundation, concrete consumption;
- floor unit on the principle of "do and forget";
- utilities do not require additional insulation;
- drenched slab is also the rough floor of the first floor, prepared for laying tile, flooring and other floor coverings;
- no need to ventilate the underground space.
Among the cons on the ground floor can be distinguished:
- in the construction of high-cap has to fill the sinus strip foundation a large volume of soil, which leads to an increase in the cost of work and budget for construction.
- I'm exploiting the floors on the ground for 7 years and would not trade them to any other structure.Thanks to the floor on the ground, in the house, supported by almost the entire winter zero temperature.It is only important to insulate the base and blind area.
Any questions on the floor on the ground, you can ask here.Here are collected the opinions of owners on the ground floor.In this topic, collect a full FAQ on floors on the ground.To get a photo report on the construction of the Finnish technology karkasnika, you can click on this link.
And in this video, reveals all the nuances malozaglublёnnogo device strip foundation.