Repairing Loose Tiles Laid Over Floor Heating Systems

Published by Shalex Industries on 29th Jan 2018

We have many customers asking if they can use our Stickit Tile Repair Kit to repair loose tiles laid over flooring where an underfloor heating system is installed.

Underfloor heating will actually help speed up cure of the Stickit Tile Repair adhesive and we suggest this is turned on after injecting Stickit.

The key concern is drilling the injection holes and whether this would risk damage the heating system.

‘Wet’ or hydronic heating pipes are usually placed in the concrete and typically tied to the reinforcing steel to keep them close to the centre. Most concrete should be 100mm deep or thicker so the pipes should be at least 20mm under the surface of the concrete but this can vary depending on the diameter of the pipes used.

For electric heating systems the heating elements are typically in the screed or in the adhesive directly under the tiles and these are more at risk of damage if the injection holes are drilled too deeply. We strongly suggest you turn the system off before injecting as a safety precaution.

Our experience is that grout typically does not extend to the full depth of the tiles and is often only 5-7mm deep on a 10mm tile. When tiles delaminate, they will often also raise the grout making the gap underneath larger.

The drill supplied in the Stickit Tile Repair kit is a 2mm solid carbide twist drill. The bit is 45mm long and we suggest placing at least 10mm into the chuck before tightening, leaving a maximum drill depth of 35mm from the top of the tile.

When drilling it is only necessary to drill until you find the ‘pocket’ or void under the tile and this is often less than or the same as the depth of the tile. You can remove a small area of grout to check the depth of your tiles if this is not known.

We suggest placing some tape around the drill bit after you have drilled the first pilot hole and this will act as a depth gauge so you can confidently drill to the correct depth with each subsequent injection hole. You should find the drill changes speed and you can ‘feel’ when you have drilled through the grout layer. If you lift the drill regularly to clear the flutes you will usually see a different texture and colour if you drill too deep past the grout and into the adhesive, screed or concrete.

We have been contacted by many customers who have successfully repaired loose tiles laid over floor heating systems and if you follow the advice given above you should find the project can be safely completed. For under tile heating systems installed in the adhesive the removal of the tile and the heating system is typically required to repair loose tiles which can be very expensive. Stickit Tile Repair Kit provides a cost and time efficient method for the repair of loose tiles over these heating systems.