Floor

1. Prepare the base:

• To concrete a floor in a flat, dismantle the old floor to slab level and remove all dirt and dust.
• In private homes, the floor is laid on the ground:
  - remove the soil layer from the inner surface of the foundation (up to 1 m in depth);
  - make a backfill with sand, creating a sand cushion and compacting it;
  - place a layer of crushed stone or gravel on the sand layer, compact it and make another layer of sand, which must be compacted again.

2. Insulate the base:

• To make waterproofing, you will need plastic film. Place it in two layers, raising it to the walls above the concrete level.
• To thermally insulate the floor, use mineral wool or extruded polystyrene foam.

3. Reinforcement 

may be necessary to ensure strength if high loads are on the floor. To do this, cover the waterproofing and thermal insulation with reinforcing mesh so that it would be inside the structure.

4. Formwork 

is necessary to ensure the distance between the walls and the poured concrete. For this, use wooden boards 2.5 cm thick.

5. Mix and pour the concrete:

• For floors, it is recommended to use concrete with a strength class of B20 (depending on the design loads). CEMARK SHVYDKYI and CEMARK UNIVERSALNYI are the best choices for this type of work.
• To calculate the required amount of building materials for the mix, use our online calculator.

Calculator
 

• Install screed rails and guides around the floor's perimeter to ensure even pouring.
• Pour the floor in one step, avoiding interruptions.
• After pouring, it is desirable to vibrate the concrete until the appearance of concrete laitance on its surface.
• To prevent intense moisture loss, the floor should be moistened with water, covered with plastic film and kept that way for 1 to 4 weeks, depending on the microclimate in the room. Read more about curing of concrete here.

Failure to properly care about concrete can cause the floor to crack.

6. Surface levelling and floor topping:

• Floor topping should be done in about four weeks. 

• For cement-sand mortar, it is practical to use cement of strength class 400. CEMARK UNIVERSALNYI and CEMARK MITSNYI are the best choices for this type of work. 

The proportions of bulk materials depend on the mortar strength class:

The strength class of the floor topping must be lower than the strength class of the base concrete. Therefore, when pouring class B20 (M 250) concrete, it is advisable to use mortar with the strength class of M 200 or M 150 for floor topping.