Hi Everyone
First time posting so looking forward to some friendly advice!
We are pretty competent DIYers and want to take on the challenge of DIY fitting a level access shower/wet room. It will have a pumped power shower and glass screens to keep water from going everywhere (so not totally open like a “proper” wet room). Its a small space so to be on the safe side we want to tank the entire bathroom (plus its good practice)
We’ve done a lot of reading online, forums etc. and we’ve read many posts in the archive but there’s a few things that seem to conflict at times and we’d like to be clear as to best practice (even if it means overkill):
1. We’ll use 25mm WBP plywood over the joists (staggered), with screws at 300mm intervals. We’ve seen some recommendations to screw at 200mm intervals and to glue the underside to the joists. Should we stick with 300mm and glue/no glue?
2. We’ve seen advice to seal the underside and edges of the ply but we’ve also seen (less so) advice to seal top side too. Is it ok to do the top side or will it affect the adhesion of the tile adhesive used to fix the backer boards (which will also be screwed down later)?
3. Because of the ply, backerboard, tile adhesives, UFH, and SLC the bathroom floor could be as much as 10-15mm higher than the shower former. To level this out should we lay 10-15mm WBP under the former so that its at the level of the rest of the bathroom when it comes to the tiling? Is there anything else we can do to keep former and rest of the floor at the same level – we had thought to lay UFH on shower former with rapidset covering the wires before tiling so this would make the height difference 5-10mm.
Tanking
4. Most people, installation videos, etc. tank under the UFH but we have seen some people advise tanking after the SLC has gone down. Can you do both or will the tanking affect the tile adhesive in any way?
5. To tank the backer boards (we will use a waterproof one like Wedi or Marmox) we’ve also heard a few different things:
a. use self adhesive waterproof tape on the joints,
b. use tile adhesive on joints, then bed waterproof tape and then apply another layer of adhesive and
c. fully tank e.g. with sheet/membrane or paint on gum.
The last one seems like overkill if already using (and paying) for waterproof backer boards – but we will do if best practice. The self-adhesive tape sounds too easy to be the best solution but we will use in a flash if you guys feel it’s as good as any other method.
Thank you all for reading this post and for your advice!
Carlos
First time posting so looking forward to some friendly advice!
We are pretty competent DIYers and want to take on the challenge of DIY fitting a level access shower/wet room. It will have a pumped power shower and glass screens to keep water from going everywhere (so not totally open like a “proper” wet room). Its a small space so to be on the safe side we want to tank the entire bathroom (plus its good practice)
We’ve done a lot of reading online, forums etc. and we’ve read many posts in the archive but there’s a few things that seem to conflict at times and we’d like to be clear as to best practice (even if it means overkill):
1. We’ll use 25mm WBP plywood over the joists (staggered), with screws at 300mm intervals. We’ve seen some recommendations to screw at 200mm intervals and to glue the underside to the joists. Should we stick with 300mm and glue/no glue?
2. We’ve seen advice to seal the underside and edges of the ply but we’ve also seen (less so) advice to seal top side too. Is it ok to do the top side or will it affect the adhesion of the tile adhesive used to fix the backer boards (which will also be screwed down later)?
3. Because of the ply, backerboard, tile adhesives, UFH, and SLC the bathroom floor could be as much as 10-15mm higher than the shower former. To level this out should we lay 10-15mm WBP under the former so that its at the level of the rest of the bathroom when it comes to the tiling? Is there anything else we can do to keep former and rest of the floor at the same level – we had thought to lay UFH on shower former with rapidset covering the wires before tiling so this would make the height difference 5-10mm.
Tanking
4. Most people, installation videos, etc. tank under the UFH but we have seen some people advise tanking after the SLC has gone down. Can you do both or will the tanking affect the tile adhesive in any way?
5. To tank the backer boards (we will use a waterproof one like Wedi or Marmox) we’ve also heard a few different things:
a. use self adhesive waterproof tape on the joints,
b. use tile adhesive on joints, then bed waterproof tape and then apply another layer of adhesive and
c. fully tank e.g. with sheet/membrane or paint on gum.
The last one seems like overkill if already using (and paying) for waterproof backer boards – but we will do if best practice. The self-adhesive tape sounds too easy to be the best solution but we will use in a flash if you guys feel it’s as good as any other method.
Thank you all for reading this post and for your advice!
Carlos