Is tiling over existing tiles safe? Concerns about cracks and adhesive.
During the bathroom renovation the tiler advised that tiling over existing tile is totally ok. I read on another thread that this is NOT the norm. Can someone please advise what are the things to check before deciding to tile over existing tile?
The tiler has done some tiling already but I am seeing the following which are making me uncomfortable:
1) A crack seems to be a showing between the old tile and the material used to adhere the new tiles (have a pic but not sure how to attach it here)
2) the material used (trade super grab) to stick is spongy to touch. Its been more than 48 hrs now since application, is this expected?
3) The tub of trade super grab says it should be used for tiles 30x30cm but my tiles are 60x60cm
Can anyone confirm if I should be worried about how safely the tiles are sticking on the walls?
Advice from 4 local tradespeople
Tiling over existing tiles can be safe if proper precautions are followed. Ensure the old tiles are securely fixed, clean, and level. Cracks between the old and new tiles may indicate poor adhesion or substrate issues. The adhesive should be appropriate for the tile size; using "Trade Super Grab" for 60x60cm tiles when it's rated for smaller tiles (30x30cm) is unsuitable and may compromise safety. Adhesive remaining spongy after 48 hours suggests improper curing or incorrect application. Consult the tiler and potentially a second expert to assess the work, as improper tiling could lead to tiles detaching and safety hazards.
Tiling over existing tiles is not a good idea but it can be done properly! The surface must be prepared, like sanding ,use of primers and a proper adhesive! It will increase weight and high of your floor so you may need to adjust doors as well
This is a poor job really. You should take off the old tiles, make good and tile again. Sometimes going for the cheapest quote is a bad idea (in fact faily often). If it is cheap, then some shorcut is often used.
Make sure condition and the surface is solid and level. However, there are some things to consider before you start:
Check the tiles
Make sure the existing tiles are stable, dry, and securely bonded to the wall or floor. You can test the strength of the tiles by gently tapping them with a wood mallet. If they sound hollow, they are not strong enough to support new tiles. You should also check for cracks, chips, or loose tiles.
Check for moisture
Make sure the surface is free from moisture, mildew, or dampness. If there are moisture issues, you should address them before you start tiling.
Check the background
The background should be able to support the weight of the new tiles. In older or poorly constructed buildings, adding extra weight to the structure could impact its stability.
Check the height
Adding new tiles over existing ones could affect the height of the floor or wall, which can impact doors, cabinets, and appliances.
Tiling over existing tiles can be a cost-effective and DIY-friendly way to update your space. However, if the existing tiles are not in good condition, you may need to fix or replace them before you can start tiling.
