Tiles keep coming off pool - help please

[teralin]

I have a 54m3 inground pool that was build last year. It is lined with glass mosaic tiles - the sort that come in one square foot backing made especially for pools. Since the pool was built, I have had many individual tiles come loose (in the region of 50) usually around the steps but also on the floor of the pool. The builder keeps coming back to replace them but more are coming off.

Can anyone think of a reason as to why this should be happening. The pool has been very lightly used and is carefully cleaned so as not to cause any further problems. We have a salt water chlorinator and an auto pH system which are both working very well so the water quality is just about perfect.

Any suggestions or experience of this problem would be helpful.

Thanks all.

[pool tech]

usually the only reason new tile come off is because water is getting behind the tile. when your guy replaces the tile that has fallen off make sure the pool gets drained and has a chance to dry where the tile is to be put back on, also when the grout is mixed to seal the tile in it needs to be mixed with an additive that makes the grout waterproof. Hope this helps