Ground floors. Features and Benefits
But it is not without a number of shortcomings. If you forget to make vents in the strip foundation (or incorrectly calculate their cross section), then over time this can lead to problems. Due to insufficient ventilation of the underground, wooden logs become covered with fungus, mold and rot. Excess moisture in the basement also leads to the destruction of the concrete floors of the floor of the first floor.
To avoid this, you can replace traditional vents with a closed ventilated underground. This is detailed in the article. “Do I need air in the basement” . But there is another option - to abandon the underground and build a floor on the ground on the basis of a strip foundation, as FORUMHOUSE experts advise.
Floors on the ground: what is itsuch
This design is a monolithic concrete base (screed). Here is the device of the floor on the ground: the screed is poured inside the perimeter of the strip foundation onto well-compacted soil, with which the sinuses of the foundation and the insulation layer are covered. Underfloor heating can be installed together with a concrete base. This design accumulates heat, so it is well suited as an element of an energy-efficient home.
The composition of the floor on the ground for a residential building.
There are the following options for floors on the ground:
- On the prepared base (well-compacted soil), a floor slab is poured, rigidly connected to the strip foundation;
- A floor slab is poured onto the prepared base, which is not connected to the strip foundation, the so-called "floating" screed.
Let's take a closer look at the pros and cons of these options.
Michael1974:
- If you fill in a “floating” screed, then the construction of the tape and the floor is “untied”. If shrinkage occurs, then the floor screed structure on the ground will “play” regardless of the foundation, cracks will not appear in the structure, because. no stress. This is a plus. But there is also a minus - the design "lives its own life", separate from all other structures.
Floor device on the ground.
With a rigid structure, the foundation / screed unit works as a single unit. The screed will not shrink, because lies on the foundation. But if the soil is not compacted well enough, after a while it may sink, and the screed will “hang” in the air. Under heavy load, if there are walls, partitions, supporting elements on the screed, this can lead to deformation of the base, cracks and loss of the bearing capacity of the entire floor structure on the ground.
How to make a floor on the ground
Both screed options have both pros and cons. The quality of the concrete floors on the bulk soil depends largely on the quality of the compaction of the bulk soil and on how correct the design will turn out.
Michael1974:
– When pouring a “floating” screed, the “foundation wall/screed” assembly must really be untied, otherwise the structure may be pinched in the tape frame. Those. the floor inside the tape frame must move relatively freely, otherwise the whole point of the floating screed is lost.
To do this, a damper is made of an elastic material between the screed and the foundation (wall), which restores its original shape after the load is removed - in this case, it is appropriate to place an isolon 8-10 mm thick. This will allow the concrete screed to “float” freely and compensate for its thermal expansion.
A common mistake is to tie all nodes as tightly as possible. As a result, increased loads occur in the structures. In the case of a floating screed, the "floor" and "foundation" elements work independently of each other.
Ground floor: device.Basic principles
An important rule: a well-prepared base is the key to a long service life of the entire structure. The filling base (the best backfilling of the floor on the ground is sand) must be spilled with water and carefully compacted in layers of 10-15 cm.
Due to the backfilling of crushed stone, when the rammer passes through it, a local impact occurs, as a result, there is a deep additional compaction of the soil layers lying at the lower levels. It is worth building up attention on the correct method of tamping sand.
- In all the instructions for vibrating plates it is written that the plate rams sand to a depth of 20-30 cm, but how well this layer is compacted, I doubt that it is enough. Therefore, I believe that for reinsurance it is better to compact the sand in layers of about 10 cm. It looks like this:
- We spread the sand in a layer of 10-15 cm;
- We pass through the sand with a vibrating plate "dry";
- Spill sand with water from a hose. It is necessary to do this not with a jet of water, so as not to break the layer, but through a spray nozzle;
It is necessary to spill water so that the sand is wet, but not oversaturated with moisture. If the amount of water is too large, then the sand base is practically not rammed.
- We pass through the moistened sand with a vibrating plate 2 times with a change in the orientation of movement;
- Spill the sand with water again;
- We pass along the moistened sand with a vibrating plate 2-3 more times with a change in the direction of movement.
What kind of waterproofing to put on the floor on the ground
After thorough preparation of the base, we proceed to laying the hydro-vapor barrier, which will protect the floor structure from moisture. It is often asked whether it is necessary to make a footing before laying this layer. After all, welded or glued waterproofing, in order to avoid damage, must be placed on a flat, rigid base.