DIY Related: Shuttering ply or something a bit better?

[Indy]

Hi,
I have a suspended floor with 4" of Celotex board sitting between the joists and my under floor heating pex pipes sitting on top of the insulation. I am planning on tiling the whole area and have a few questions regarding what ply to use. I've done a quick search around here and generally any WPB ply is recommended with shuttering ply frowned upon when used in areas of under floor heating.

I plan to use Ditra matting on top of the ply and then my tiles on top of that. Can I get away with using el cheapo shuttering ply as the Ditra matting will provide a waterproof and decoupling layer or would I be better off off still using WPB ply?

Also would a gap of 6mm between the plys filled with silicone to allow for expansion be too big?

Cheers

[Dave]

Use the Wbp ply.. OSB isn't stable enough to tile too directly..

[david campbell]

wbp ply for me also and try and leave about 2/3mm between the ply!

[Indy]

Thanks gents, Dave do you mean just use the cheap shuttering ply?

[Dave]

NO!!..

[Ken Bruty]

NEVER EVER use shuttering ply, it will warp unbelievably, I've seen this with my own eyes.

[Indy]

LOL, That clears that up.

Cheers guys.

[Dave]

NEVER EVER use shuttering ply, it will warp unbelievably, I've seen this with my own eyes.

Any pics, are they like this..

[Ken Bruty]

Where did you get that future picture of me? I've heard that happens after years of forum addiction