What sheet to use for waterwall

[NAM]

Hi, All -

I'm in the process of constructing a waterwall which will have water trickling down the face of split-face slate tiles into a fishless reservoir.

For the backing wall of the waterwall, (onto which the waterproof membrane and tiles will be adhered) I need to buy the right sheet material. I looked into "marine plywood" 18mm, but it is incredibly expensive in the UK and around £100 sometimes over £200 and much more for one 2.4m x 1.2m sheet. I would need 2 of them.

I've also read about WBP plywood and OSB boards that are much cheaper (about £20 to £30 each for the same dimensions), but need to know if they will be sufficient for the waterwall. Marine plywood seems to be the obvious best for water resistance, but if it is going to have a waterproof membrane laid over before tiling, is WBP sufficient?

Thanks in advance

 

[SarahT]

Welcome to the forum (I'm a new member, too. They're really nice and helpful here). I'm not an engineer, so all this needs some good thought from others. Will the waterwall be interior or exterior, how tall, and what surface or wall will the back be put on to, since I know it can't be freestanding. Even not knowing that, though, I'd be looking at "cement board" which is used on bath walls or to build a shallow/ narrow concrete block wall and attached the tile to the block. I'm safety conscious, so remember that most vertical water falling splashes, so take care the floor and pathway in front of the amazing wall isn't a slip hazard. Your project sounds interesting; can't wait to see it done.

 

[NAM]

The waterfall will be exterior. The height and width is 1.6m by 2m.

I had thought about concrete blocks, but need the space behind it for the plumbing. It's not completely ruled out but exploring options.

If I go down the sheet material route, I've been looking at OSB, WBP ply, Marine ply. I had considered cement boards, but not sure about how fragile these are if they are mounted vertically outside between wooden posts and subject to wind

 

[GBBUDD]

Wonder board is a better alternative to marine ply it will not rot. You may not have wonderland in uk but it's simply lightweight concrete in a 1/2 inch sheet with a mesh to hold it all together. You can also glue the slate to the wonderland to help create more depth to the project. But like marine ply it is not waterproof your studs will see weeping. I would lean toward the cinderblock myself. I'm actually contemplating something similar but I already have a lot. So who knows

 

[j.w]

and welcome @NAM

 

[addy1]

welcome to our forum!