Tiling onto 18mm t & g moisture resistant particle board

[fruitcake]

Hi all,

I have posted on here before asking your opinions of tiling onto 18mm wbp ply screwed directly onto the joists. However, what do people think about using 18mm moisture resistant tongue and groove instead?

 

[Jasonb]

Don't do it, I would not want 18mm under carpet let alone tile as it flexes too much. 22mm under carpet and 22-25mm WBP ply under tile.

Jason

 

[Richard C]

Not worth the risk; for the small additional cost, I would only use WBP.