Installation of underfloor heating on a tile: is it possible?

Is it possible to install an electric heated floor without removing the tile and cover it with ceramic tile?
Marina

Expert Answer

Good afternoon, Marina!

Laying a new ceramic coating on top of an electric heated floor laid on an old tile is allowed. It is important to follow a few rules.

1. It is necessary to carefully analyze whether an increase in the height of the floor by 20–25 mm will prevent the doors from opening, hide engineering communications, etc.
2. The old foundation should be monolithic. To get information about its quality, tap the entire tile with a wooden hammer. If necessary, individual tiles are removed, and voids are filled with cement-sand mortar.
3. To increase the adhesion ability of the old coating, it is recommended to go over it with a grinder with a diamond disk, make notches, drillings, etc. A less effective way is to treat the base with primers of the “Concrete contact” type.
4. Part of the glue is applied to the old tile, after which the heating mats are laid. After that, according to the usual technology, the laying of new ceramic tiles is carried out. The total thickness of the adhesive layer should not exceed 10-15 mm.
5. The seams of the new and old coatings are not allowed.

As you can see, the difficulty lies only in preparing the base of the floor. Nevertheless, if possible, it is better to remove the old tile, and put a layer of thermal insulation in its place. This will prevent heat leakage into the floor and reduce energy costs.