Wooden Bathroom Floor Replacement

[kevinwebster83]

Hi,

I'm in the process of completely renovating my bathroom and my next job is to prepare the floor ready for tiling. Currently, the flooring consists of damaged floor boards which i'm planning to take up and replace with WBP plywood.

I've already looked for some 25mm boards but they seem to be both expensive and very hard to come by. Would it be just as good to lay 2 layers of 12mm boards, running the top layer 90 degrees to the bottom?

Thanks in advance,
Kev

 

[Richard C]

In most cases 18mm WBP is sufficient but it does depend on the floor – size, span, pitch & condition of the joists, if in any doubt you need to go thicker. Where are you looking for the WBP? I know B&Q stock up to 18mm but for the thicker stuff you will probably have to go to a Builders Merchant. I would not advise you use 2 layers of 12mm, it will have nowhere near the same rigidity.

Price wise, you don’t need marine ply & it’s considerably more expensive then WBP which you should be able to find locally for around £25 for 18mm or £45 for 25mm; I don’t consider expensive when you consider the cost sq/m of decent tiles, what were you expecting to pay? You can get it cheaper if you shop around but is it really worth the hassle to save a couple of quid!

 

[kevinwebster83]

Thanks for your reply. The room is relatively small, i'd say maximum of 2.4m by 2.4m. Joists are in excellent condition and definitely no more than 25cm apart.

So far i've look on the B&Q website, Wickes and some local builders merchants. I don't really know how much i was expecting to pay, i guess i was just comparing it to standard plywood prices.

If i went for the 18mm WBP, would overboarding with backerboard be advisable? If so, would 6mm or 12mm be best?

Thanks,
Kev

 

[Richard C]

If i went for the 18mm WBP, would overboarding with backerboard be advisable? If so, would 6mm or 12mm be best?

Some will advise a backer overboard (6mm on floors) or Ditra matting. It will certainly not do any harm but, personally, if replacing the floor with new WBP, I don’t overboard & tile straight over the ply. I’ve never had any problems but you must use a high quality trade flexible adhesive & grout, not cheap DIY stuff. Seal the back of the ply with an SBR (waterproof) based primer/sealer before laying. Do not prime to tiling surface unless the adhesive manufacturers advises to do so.