Laying down 25mm WBP plywood ready for tiling

[aled]

Hi,
I am replacing my bathroom floor with 25mm wbp plywood. I will be using 3 sheets of plywood and was wondering how best to 'butt' them together. I have seen on various forums that I need to leave about a 2mm gap between the sheets. Do I need to fill in the gap with a flexible adhesive and then tape over it with something similar to plasterboard tape? What would you recommend?

Thanks in advance

[grumpygrouter]

Yes you need to leave a gap for expansion. The adhesive when you lay the tiles will fill the space.

[CJ CERAMICS]

remember to seal the edges of the ply otherwise the moisture from the adhesive may penetrate the ply and cause it to swell.

chris

[aled]

Do I need to seal all of the wbp plywood or just the edges where I have made cuts in the plywood? Once i screw the plywood into place should i then take the sealand over the screw heads just incase the tile adhesive causes damage?

Thanks
Aled

[Scott]

Seal the edges an BACK of the ply but not necessarily the face of the ply. That will depend on your adhesive manufactureres instructions.

The screw heads will be fine, the moisture content in the adhesive is negligible and isnt enough to cause damage. Nor IMO is it enough to swell the ply at the edges? if it was then it would be enough to swell the surface of the ply. The edges and back are sealed to prevent moisture ingress but from other sources.

[aled]

This may sound stupid but can you tell which is the front and back of the wbp plywood? Or does it not matter?

[Sir Ramic]

It doesnt matter.