Electric floor screed: selection and installation rules
Good afternoon! An apartment in a panel house built in the 70s. The maximum height of the screed (kitchen and corridor) can be only 4 cm, what type of screed is better to use, provided that the floor is laid unheated wiring without corrugation?
Olga
Expert Answer
Hello Olga!
The uniqueness of your case is that the minimum thickness of the screed based on a sand-cement mortar according to the current SNiP is just 40 mm. Thus, in your apartment you can apply the cheapest and easiest way to equip the base of the floor. If you want to strengthen the screed with reinforcement, then this will reduce its height to 20 mm, and fill the remaining 20 mm with a self-leveling mixture for the construction of bulk floors.
By the way, reducing the thickness of the screed due to fiber reinforcement makes it possible to insulate the base with plates of extruded polystyrene foam. In your case, grooves for laying electrical wiring should be made on their lower surface.
When creating a screed of small thickness, you should follow a few simple rules:
- it is necessary to untie the draft base from the floor slab. Mechanical bonds that appear due to the adhesion of the cement-sand mixture to the base, lead to the transmission of vibrations and loads. Since this leads to cracking of the screed, its installation is carried out along a layer of release material, for example, waterproofing from a polymer film;
- a reinforced damping zone should be created around the entire perimeter of the room. For this, before starting concrete work, a special polystyrene foam tape up to 20 mm thick is mounted on the lower edge of the walls. This simple method minimizes the risks associated with the appearance of deformation cracks during thermal expansion of the screed.
In the end, I would like to comment on your decision to lay the wiring on the base of the floor. It is unclear what caused it if there is a great way to install electrical cables around the perimeter of the room. You can easily hide them from the eyes with the help of skirting boards with a cable channel and get complete maintainability of communications. We recommend that you carefully analyze the benefits of this method.
