www.ultimatehandyman.co.uk

The "floorboards" of my modern house (built 2000) are some sort of large sheet particle board. I want to lay ceramic tiles on my bathroom floor and want to know whether I can tile direct on to this or does it need treated in any way. What sort of adhesive and grout should I use? The present flooring is carpet.

Any chance of a picture please?

Sorry no. The whole of the upstairs is floored out with this stuff, so it goes under the partition walls. The builder was Taywood, so this is obviously standard procedure at that time.

We have a 1995 house, the flooring is grade 5 WBP (waterproof and boil proof ply) over polystyrene sheeting and concrete beams.

We had the same problem but only because the floor Weetabixed after a bath waste leaked. We replaced it with WBP 25mm 8 x 2 t&g sheets and have Aquapanel to tile on. Aquapanel is a cementitious reinforced board that is rigid enough to lay tiles on. You need a flexible fast set adhesive though that will allow for movement in the floor.
Ask the guys they'll tell you in more detail, I'm just a mere girl! There's a link for the Aquapanel.
http://www.ultimatehandyman.co.uk/tilin ... floors.htm

Guess this "floorboard" stuff must be waterproof as can see that there have been some leaks from the bath in the past and the "floorboards" are still OK. Does this mean that the floor tile adhesive will not stick to it?

I've no idea, although I think they recommend that the base is dry as you would expect.

This seems a bit like overkill if the original base is already waterproof. Housebuilders aren't going to put in floorboards that disintegrate the first time there is a leak - in fact thinking about it we have already had a major leak from the other bathroom and although it almost brought the ceiling down, the floorboards were OK.

catweasel wrote:This seems a bit like overkill if the original base is already waterproof. Housebuilders aren't going to put in floorboards that disintegrate the first time there is a leak - in fact thinking about it we have already had a major leak from the other bathroom and although it almost brought the ceiling down, the floorboards were OK.

Dream on Catweasel.

House builders use the cheapest stuff they can get their hands on.