wrong plywood for bathroom tiling ?

[lazy]

I have just layed plywood on the wooden floorboards in our bathroom in preparation for tiling. I now see (should have found this forum first) that I should have used external plywood - as far as I know I just have normal plywood. Is this going to be a problem? Do I need to redo it or can I PVA it or something?

I found cutting the board very difficult to get right. I am not sure I can face doing it again.


I didn't see different types of plywood at Jewsons, otherwise I might have thought to ask...

 

[noseall]

was it w.b.p. plywood?

 

[lazy]

I don't think so - I just asked for plywood

 

[lazy]

Aha, it has these numbers on it (and my google assisted interpretations) -

EN 13986 (general building stuff)
EN 636-3 S (636-3: exterior conditions).

So, it looks like I do have the right stuff and I guess Jewsons must only sell exterior grade plywood .

It would still be interesting to know what the problems are with using interior grade plywood - does it rot, layers separate or something?

 

[gcol]

Bathrooms and kitchens = water
Tile adhesive = water
Interior ply = no likey water

water / no likey water = trouble


Seriously though, interior ply doesn't use water resistant adhesives to glue the layers together so we use exterior stuff that does. If you get internal stuff wet, the adhesive can break down and it can de-laminate.