by Daniel Tester »
Fri Oct 26, 2007 9:50 am
i think if the grout has crackd the tiling will lift too. I layed tiles on a floor of chipboard as the builder told me it would be ok. i used flexi glue , but the floor has still failed. the main problem was that there were hot water pipes under the boarding that was producing massive expansion movement.
as a tiler i have not found a good solution for tiling on to wooden surfaces, but would definately recommend that the floor boards are lifted and the joists are re fitted into the walls, extra joists are added where bathtubs etc are to sit and that cross noghgins are added. then add 3/4 " marine ply with screws every 30 cms. As adding tiles to this willl produce a new floor height of around 3-4cm higher than the original you can see that most people will suffer a small step whereas if you are resetting joists , then you can lower them to give a perfect final level!
although this gets expensive if the tiled floor is to be installe upstairs as the downstairs ceiling will have to be re plastered or even replasced!!