Hardwood or WBP ply for shower

[lostdiyer]

Is there a difference between WBP plywood and hardwood plywood? I’m trying to determine if hardwood plywood would be sufficient for a shower base.

 

[DP]

I would imagine what would be at home in that environment is exterior grade or marine plywood. Glue/ adhesive will not break down

 

[lostdiyer]

I would imagine what would be at home in that environment is exterior grade or marine plywood. Glue/ adhesive will not break down

Would hardibacker be a better option?

 

[Madrab]

If the space/board is to be tanked then hardwood ply would do the job.

As suggested WBP (weather and boil proof) ply is made with moisture resistant adhesives and better to be used in humid areas and then there's marine ply which is the top grade of plywood made with waterproof adhesives and is much more resistant to more wet conditions but is super expensive and probably overkill in a domestic bathroom setting

OSB3 (oriented strand board) is also a moisture resistant board and has similar properties to WBP ply and could also be used.

 

[lostdiyer]

If the space/board is to be tanked then hardwood ply would do the job.

As suggested WBP (weather and boil proof) ply is made with moisture resistant adhesives and better to be used in humid areas and then there's marine ply which is the top grade of plywood made with waterproof adhesives and is much more resistant to more wet conditions but is super expensive and probably overkill in a domestic bathroom setting

OSB3 (oriented strand board) is also a moisture resistant board and has similar properties to WBP ply and could also be used.

Will try to find WBP ply locally as delivery is costs are expensive. I’m planning on tanking the walls up to the lip of the shower tray. Is it better to tank the ply too? And how would this be done?

 

[Madrab]

And how would this be done?

Tanking a wet space means tanking the floor and wall up to at least head height, that ensures any water that gets through won't get to the wall covering below. That also means using a waterproof tape to seal up the edges/corners and any exposed joints etc. You'll never tank the whole floor area as the trap etc usually has to drop down below the plinth/floor but if everything else is sealed up properly then water shouldn't ever get to those sections

Using a liquid membrane to tank the space is the cheaper option (Mapei) but is just as effective, just primer the space well. I use that a lot of the time.

BTW, OSB3 is available in the large sheds and can be just as effective and usually not as expensive .