tiles on chipboard Advice and information on tiling and fixing tiles to a variety of surfaces

[gary w]

hi all
i am about to put in a new kitchen upon removing the old cracked / loose floor tile's i find the floor is made from 1" thick chipboard i am told this is a " floating floor " my question is how do i tile the floor again and prevent cracking of the tiles on this semi flexible floor keeping in mind the vibrations from a washing machine ?.
the gap left to keep the floor to the next room level is no more than half an inch so i assume adding a layer of ply wood would have to be ruled out !

any help would be greatly appreciated

[thedoctor]

Firstly we would strongly suggest removing the chipboard (which we are assuming is laid on a concrete or screeded floor, and either laying the tiles directly onto this immovable surface or relaying the timber floor in 25mm plywood if smething, for some reason, does have to be reinstated. The plywood should be fixed solidly at 400mm centres in both directions before any attempt is made to lay tiles. If there is any movement whatever in the floor it will not take long (days rather than weeks) before the floor starts to crack up. If you are going to lay on Plywood then paint it first with PVA adhesive ( See our project on PVA) the first two coats should be diluted 50/50 with water so they soak in well and the last coat should be undiluted. Adding a T cup full of PVA to a bucket full of powder mix tile adhesive is also a good idea.

[gary w]

hi again
as far as i am aware under the chipboard is a 4 or 6 " layer of polystyrene acting as insulation i have been told a lot of propertys were built this way at the begining of the 90's . is there any type of tile adhesive that would give sufficient flex to allow me to tile direct to the chipboard ?.