Advice Please

**theodotcom** · 28-09-2008

Hi

I'm new to the forums and am after a bit of advice, I had some tilers in to tile my bathroom and kitchen floors.
They tiled straight onto the floorboards and did not use a primer of any kind.
They used out of the tub adhesive and used so much that it raised the floor by about 8mm. (think it was cerafix from b&q)

The problem i have is that they walked out of the job (guessing they knew they screwed up). I've had someone come in and grout the job out 3 times so far. However the grout keeps breaking up and does not seem to set.

Is this something that can be fixed and if so how or does everything need to be removed and started from scratch.

Thanks for any advice.

**whitebeam** · 28-09-2008

I would lift the tiles before they come up anyway, The adhesive certainly is'nt any good for floors. 8mm is a lot of addy, I would'nt think the adhesive has even gone off yet. If the grout is breaking up I have feeling the tiles are flexing on the floor boards

**andersontiling** · 28-09-2008

Originally Posted by whitebeam

I would lift the tiles before they come up anyway, The adhesive certainly is'nt any good for floors. 8mm is a lot of addy, I would'nt think the adhesive has even gone off yet

agree...see the slate on 3mm ply thread may give you some pointers

**Daveyboy** · 28-09-2008

Hi Theo, the grout is cracking because the tiles are not on a stable substrate and thus keep moving which in turn is cracking the grout. I wouldn't be suprised if some of the tiles are already loose (you can normally tell if you tap them and they sound hollow) I would have put down 9-12mm ply screwed down (150mm centres) on top of the floorboards, primed and used a flexi adhesive (the type flexi adhesive I'd use would depend on how much flex was in the floor), with a flexi grout.

The only thing I can think of is that you lift it all up and start again....sorry...you might be lucky and be able to scrape off the old adhesive off the tiles...

**a1tiler** · 28-09-2008

1st lot didn`t know what they were doing, and the grouter might not know anything by the sounds of it !!
do as the guys are saying and get them off the floor and do it again this time use a pro tiler, ask on the forum these guys know what they are talking about.

**Dave** · 28-09-2008

Sorry to say this but CERAFIX from b&q isn't suitable for tiling tinber floors let alone onto floor boards.......

The wrong product has been used and you have a re-tile on your hands i'm afraid....

If you need a fixer to re-do it then ask for one on here...

**theodotcom** · 28-09-2008

think im going to give this a shot on my own first. nothing to lose I guess and definately cant make it look any worse

whats the thinnest board I can get away with putting over the floorboards, I read that a lot of people recommend 18mm but that would be way too much, is there anything I can get about 6mm that would work?
thanks again for any advice

**Dave** · 28-09-2008

Take a look around our prep forum and then if you still need help then come back to this thread.....good luck...

Tile Adhesive, Grout and Prep Forum - TilersForums.co.uk | Tile Forums | Tiling Forum

**Alberta Stone** · 29-09-2008

Minimum subfloor is 2 layers total thickness of 1 1/8 inch on 2 x 10 joists on 16 inch centres.
Top layer should be plywood and it should be screwed and glued into place to provide a rigid substrate.
Plywood should be primed with Mapei primer L. They say you can dilute it with water, but I usually use it straight on plywood.
Floor should have cross bracing and it should be checked for deflection (which is flex).