base for stone resin tray

[rssteve]

and just gone to fit my stone resin shower tray in my new extension and it asks for a minimun of 18mm plywood underneath. now the extension has been fitted with 22mm chipboard, from experience is this essential as it will mean i have to remove a section of new flooring and fit ply which is not the easiest of jobs as it will be sitting against a stud wall and the joist hanger down the other side. thanks in advance.

 

[Fluffster]

Ply is the preferred material due to its water resistance and load bearing capabilities.
Chipboard turns to porridge when wet unless you have the green stuff which turns to weetabix

I would consider even a thin sheet of ply over the the entire area which has to be tiled to maintain the integrity of the floor if you ever had a leak.

Pete

 

[rssteve]

oh yes i just thought if im tiling i wanna ply anyway, wish the builder had used ply now as it appears from my nedroom im gonna have probably a good 25mm step un into the ensuite! thanks

 

[Richard C]

Do yourself a favor BEFORE you go any further & read the Tiling Forum sticky & archive posts.

If you over board the crapboard you should use 12mm ply, anything thinner may give you problems; it’s also important how you fix it. You should have specified minimum 18mm WBP ply for a tiled floor &, personally, I would take it up & replace it; you can then get rid of that large step at the threshold.