Pouring the floor with concrete is feasible on almost any surface. The technology will be slightly different, but the basic steps are the same. If the substrate under the concrete will be soil, it is likely to require a backfill. It is imperative to find out the level of groundwater in the area where the building in which the work is carried out stands. Groundwater in this place should not run higher than four meters from the ground surface. Otherwise, it is possible underflooding or moisture ingress, which will lead to the accumulation of excessive moisture in the room. Backfill is made multi-layered. First poured gravel (5-10 cm), watered with water, compacted. The next sand (10 cm), again watered and compacted. A log with a flat board nailed to it can be used as a compactor. The last layer is placed crushed stone (10 cm). On top, at the end of the backfill, you can once again put a little sand or crushed stone, carefully compacted. During the backfill, it is necessary to control the surface with a level.
Waterproofing, thermal insulation works
The surface should be flat. Especially carefully examine the surface, if you do sprinkling, gravel should lie a dense layer, without any sharp protrusions. For waterproofing use any waterproofing materials. At the moment the construction market can offer a choice. In principle, it is perfectly suitable and polyethylene film 200 microns thick. The material is laid overlapping, the edges are fastened with any adhesive tape. After that, the thermal insulation material is placed on top. The procedure is repeated as in the laying of waterproofing. There are enough materials to choose from, too. You can use foam plastic, mineral wool, polystyrene foam, polyurethane foam. This is not a complete list.
The material can serve as a mesh of metal or plastic. If there is a need for stronger floors, a framework of reinforcing bars of 8-18 mm thickness is used. The frame should be located on 1/3 of the pouring height, so it is laid on specially installed stands about 2-3 cm high.
Guides, or as they are called by professionals, “lighthouses” are guidelines for the most even pouring, greatly simplify the control of the surface level. For this purpose, thick concrete is mixed, it is formed from small “plushies” on which the pipes are laid, you can use wooden bars, you can even use aluminum profile. In fact, this is the guide. They are used to determine the evenness of the casting. The guides, pre-lubricated with special oil (or used machine oil) are placed on the previously prepared cushions, the position of levelling is adjusted by the horizon or leveling instrument. The buns should harden a little, you can proceed to the next stage of the work.
If the area of the room is large, it makes sense to equip the formwork. This will make the pouring process easier. For the formwork used conventional boards, which divide the room into how many equal pieces. The height of the formwork is set at the level at which the concrete will be poured.
Concrete mixture and pouring
If there is a time limit, it is worth pre-ordering a ready mix at the factory and pour the concrete floor at one time in a matter of hours.
You can make the mortar yourself. For this purpose, you will need a concrete mixer and material. Sand 2 parts, cement 1 part, crushed stone 4 parts, water 0.5. The mixture is thoroughly mixed in a concrete mixer and immediately poured. The poured concrete is then leveled with a shovel, the mixture should be pierced vertically in several places to allow the remaining air to escape.
After pouring, the concrete is allowed to stand for 3 days. During this time, once a day it should be slightly moistened with water. The floor is covered with polyethylene and left for 3-4 weeks until it finally hardens. The last step will be the application of screed. For screed used liquid cement mortar, or any self-levelling mixture, then left to dry out, usually the process takes another couple of days.