Hi, I need some 9mm plywood to line the floor of my bathroom (original planks would be underneath it).

One supplier has WBP plywood (water/weather boil proof).

Wickes has exterior (which google says is the same as above).

I hear of marine plywood ... finding it maybe another story.

What would be the correct material to use in a bathroom? It will have a shower, not the walk in variety but with doors. The floor will be covered (I hope) with some kind of plastic tiles.

Cheers
Charles

WBP ply will do the job,but you will want to prime the edges and underside with a sbr primer,this helps stop moisture ingress from below etc...

or you could put a 6mm cement based backerboard down glued and screwed...and put your floor covering onto this..hardie/aquapanel etc would be my choice

Just spotted your posts.

Love your username.

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It may seem difficult at first! But everything is difficult at first.

The noo!!..

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By eck! ©

Am I am being followed?

A Glasgowegian spots the Och Aye (for those South of the border ... "och aye" is used as a pause between parts of speech, usually expressed by males, when the conversation has come to an end and there is nothing to say ... so ... Och Aye [add anything you like].

Then I get someone from Whitley Bay, next to Tynemouth as in mouth not as in Portsmouth, a wye aye man.

Are yous two following me as I have lived for 10 years in Newcastle (howay the lads) and double+ that just up the road from Geordieland? Hokay the noo to you too Geordie.

Och aye ... any plywood will do as it was September when I removed the cistern from the throne to plaster the wall behind it


Charles

There's a problem with that!........I'm a Yorkie by birth!...

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By eck! ©

9mm marine plywood (not exterior grade) has been ordered. Top side will be covered by plastic tyles (Amtico). Do I need to do anything about "priming ?" edges and underside before it is laid on the floor.

The floor is that of a bathroom, it will have an ordinary shower enclosure on it (with doors etc).

sbr or an acrylic primer u/side and edges...

screwed down every 200mm (into joists)...

i would have still went for a cementbased backer board myself...but heh-ho you have bought it now..

leave a 5mm gap around the edges of the perimeter off the room for any exspansion.

it is for vinyl tiles (amtico) not ceramic stuff. Would the cement board remain in tact over uneven planks on the floor or would it crack under the weight of feet on it.

After I bought the ply I read the amtico instructions and they "appear" to recommend sealing for "exterior" plywood. I am supposed to have bought "marine" ply, but it is belt and braces ... seal it once more if I have to. Are you suggesting SBR primer for the underside and edges or something else (what?).

Cheers
Charles

wbp and marine ply are both exterior ply
yes prime u/side and edges this helps to stop moisture ingress.

the c/based backer board would take more off a load/stress than the ply and is ideal for bathroom wall and floors.
as for the fixing off your vinly tiles re priming the face of you the ply follow the mfr guidance.