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Cracked ceramic tiles where old concrete floor joins new one
We had a kitchen extension built about 2 years ago and we have a concrete kitchen floor.
The builder laid ceramic tiles on the floor and all seemed well until a few weeks afterwards when a long hairline crack appeared through 3 tiles that covered the area where the old kitchen and the new extension joined. We rang the builder who came out and removed the cracked tiles and replaced them with the new ones I had purchased. A couple of months later, two of the new tiles he had laid developed hairline cracks. We have now noticed that a further 3 adjacent tiles have developed cracks. The cracks are just in those tiles that are laid where the old concrete floor joins the new one. Can anyone please advise me what to do next? Can the problem be rectified without taking up all the kitchen floor tiles?
Can be a tricky one really depends on just how much movement there is, but the only place you appear to have a problem is on the join between the two slabs so only the tiles on the joint will be affected. You could try relaying the affected tiles with flexible adhesive and if the movement is not too great this may do the trick.
Answered 12th Oct 2013
If the cracking is purely limited to the intersection of the new / original concrete floors it would suggest that there is some thermal / differential movement in the floor. If the new floor is only 2 years old it is most likely better insulated than the original floor therefore the expansion / contraction limits will vary between the two floors causing a stress point along the line of abutment. Are there any heating pipes etc in the floor near to where the problem occurs?
I would suggest the damaged tiles are chopped out, the joint between the new floors is raked out and repaired with the addition of a reinforcing medium such as galvanised wire mesh and once dry replacement tiles are then laid on a flexible adhesive to allow for any future differential movement
Answered 13th Oct 2013
Hi, this will keep happening due to movement of the substrates. He should have started at that point with a full tile either side, leaving the joint on the concrete line then putting a silicone joint, you will have to now cut the tiles to make the movement joint. Also you can get a movement profile from Schluter ask at your nearest tile stockist. If you do not want to take the tiles up maybe ask your builder to run an angle grinder along the crack to make a joint and then infill with silicone. Flexible adhesive will not solve this problem, only a movement joint will.
Answered 13th Oct 2013
you will never stop the cracking , only solution would be to either re lay screed entirely or hack up tiles and relay them on top of ditra mat which the builder should have told you about before laying ,it would have been an extra cost but,it would have been your choice
Answered 1st Sep 2014