tiling on a wooden floor

[nospam]

Hello,

I know that before you tile it helps to have a level floor, and with a concrete floor you could use a self-levelling compound. but how do you prepare a wooden floor? I read that you should put 18mm board down.

But: I was thinking of fitting electric UFH in the bathroom. Now if I do this I will need 18mm board, then the aquapanel (say 9 mm), then the UFH cable (say 4 mm), then the tiles (say 5 mm). This comes to a total height of 36 mm. Won't this make a bit of a step as we move from the landing into the bathroom?

I can't see that I could use a levelling compound as surely it would fall between the gaps between the floorboards?

Thanks.

[The Natural Philosopher]

A strange idea, but hey, whatever empties your bank account..

No, you won't. All you need is a stable floor that does not flex, which if its chip already on decent wood joists, may be enough, and some tile cement.

If its floorboards, is worth lifting them and shoving insualtion undereneath to stop downstairs getting hot, then replacing with 18mm chip, and maybe doubling up on joists if there is a lot of flexure.

This comes to a

Indeed.

Take the floorboards up and put in rockwool or kingspan, then use 18mm ply after stiffening up the joists if they 'bounce' and lay tiles using at least 6mm of flexible Adhesive. I guess the UFH coils go somewhere under the wood - haven't used electric. I'd be far more tempted to lay some plastic pipe under the floor between the joists and hook it up to the radiator cqts frankly.

[robert]

I used well PVA's 18mm ply on stiffened joists , electric floor mat covered with tiling adhesive per instructions then tiles on top.

Make up any height difference with a wooden door threshold.

As I replaced 25mm floorboards with the ply and allowing for carpet and underlay outside the bathroom the height difference wasnt much. Robert

[nospam]

Sorry I thought the 18mm wood went on top of the floorboards; i didn't realise it replaced them! I think eUFH cable goes in the adhesive but I will look into the wet UFH.

[The Natural Philosopher]

It can go there, and for a quick and dirty, thats what you do..it's to provide a stable base for tiles, but if you are shoving in UFH you might want to lift the floor anyway.

I think eUFH cable goes in the adhesive but

If it does that is fine too, but with a height problem you may well want to consider removing the floorboards anyway, and insulation under will stop a proportion of the heat heating the downstairs ceiling.

I have a friend who had a pretty cheap and nasty refurb carried out: So cheap and nasty that they never insulated the CH pipes running under the bathroom floor. 15m copper, and they warm it enough to be really pleasant in winter.

If you get some of the flexible pushfit stuff and lay kingspan on the ceiling below, and zigzag the flexi pipe up and down the joists, before relaying a ply floor, you have an instant very cheap wet UFH system Strictly you should regulate the temperature in the pipes down to a level where it won't cause expansion/conrarction issues in the wood and tiles: In practice one or two lengths of pipe up and down between each joist won't be a problem unless you regularly run your boiler at max temperatures.

Couple that lot to your existing raditaor and use a TRV for a crude bit of regulatin.