Laying Floor Tiles

No idea about proposed bonding approach but ...

A friend did his kitchen floor in slate before xmas and used 1/2" ply screwed down (well) over the old floorboards. It still looks tip-top after 4 months of traffic.

You could consider using a similar approach and if the chipboard is in good enough condition you might be able to use a thiner ply say (9mm) (anyone else got an opinion on this?).

The problem with overboarding is that you loose some depth on skirting and introduce level differences between rooms. This may or may not be a big problem depending on the situation.

Also, I recently tiled my bathroom floor with cork tiles and was forced to overboard with ply. So if you change your mind about materials see

for info.

HTH,

Alex.

You need to think this through.

1) slate will strike cold on bare feet so you may need undertile heating. 2)if you are going to heat, you may well want insulation under the floor. 3)if you are fitting insulation under the bathroom floor, you need to ensure that the rest of the space under the floor for other rooms has adequate ventilation. 4)the final floor level needs to be almost the same as the old surface otherwise things like the bog wont fit or reseal properly Having resolved this lot, you will need to make the floor very very rigid. Ensure the joists are sound and cross braced. Lay plywood, glueing and screwing to the joists at max 300mm centres. consider a second layer of ply ( more glue and screws) to brace across any joints in the first layer.

Obtain the specialist tile cement designed to tile onto wood substrates and that is compatible with slate and is suitable for UFH if you decide to use it. This is flexible and will allow the minute degrees of movement that may still occur. One manufacturer is BAL. you can buy their products from tiles R us. You will also need a flexible, waterproof grout.

How do I know all this? I've just finished tiling my bathroom floor, insulating and installing UFH. So far so good and the floor temp is just at a level where it does not feel cold. If I set it warmer then the running costs get silly.

HTH

Bob

As long as there is not a lot of movement in the chipboard, a thick (10mm or so) bed of flexible tile cement will see you right. I used an ardurit product for our bathroom. The first ultra cheap tiles in a 3mm bed of non flexible flaked off, especially where the bog leaked, but the latest ones are holding up well.

Grouted woith bal grout, no special additives (should and could have added waterproofing, but couldn't be arsed)