Hi lads, I,ve just laid a ceramic floor tiles onto a wooden floor, all tiles are down solid and will not move, but grout on 1 tile is cracked, I know what the problem is, when laying the ply wood onto the floorboards being an old house, there were 2 water pipes and 2 electric cables running directly under the ply wood which meant that for saftey reasons I couldn,t screw large screws through into the joists above 2 of the tiles just smaller screws into the floorboards (therefor giving me a bit more movement than I would like) The question I would like to ask is can I put some kind of liquid sealer on top of the grout to give it more flexability and to stop it cracking, I use Morcros fast set adhesive which also doubles up as a grout. Thanks in advance for your help.

nothing that I know of mate,with hindsight could you have run a bead of no nails type adhesive close to service pipes and cables to secure ply in these areas?

Could've stuck it down with a flexi addy

Originally Posted by whitebeam

Could've stuck it down with a flexi addy

or a flexi addy!!!(didn't think of that one whitebeam!)

and flexi grout

Why not lift the two tiles in question, carefully drill a couple of pilot holes into the ply and pump in a small amount of expanding foam into the area and re fix tiles. The expanding foam would fill the void and suppress the movement.

Thanks for the replies lads, I thought of a flexi grout but it might not match in the colour I,ve already used on the rest of the tiles (mine is a light grey finish) and would I not have to take all the other grout out with an angle grinder creating a mess in the now finished bathroom????

Is it a flexible adhesive that you've used, was it tubbed or bagged?

Always spf and flexi grout on Ply boards, also always glue n screw, and don't be tight with the screws, like some i've had to re do for others...........