Hi everyone. 2 bathrooms to complete!

[DDD]

Hello, been reading for a while and getting lots of helpful advice. Especially when the builders were going to put 6mm ply on top of osb for tiling the floor!
We are having an extension built, meaning 2 new bathooms. I'm an experienced DIYer, done a couple of bathrooms in the past but basically made do with existing structure. This time having a blank canvas, trying to do everything correct. Already posted a question about screws for the marmox boards as was quite eager to start ordering everything I need.

This is what I have planned. Two bathrooms, main and ensuite.
Both have mix of block and stud wall, suspended timber floor (3 foot crawl space underneath). Ensuite will be a wet room.
12.5mm Marmox boards on walls and floor (might reduce down to 10mm for the floor). Floor has 18mm WBP, well screwed down/supported.
Fixing Marmox with adhesive (Mapei Keraquick) and screws/metal washers. UFH (Devi-mat), SLC (haven't chosen which one yet), then tile (300x450 porcelain on wall, 300x300 floor. (Mapei keraflex maxi for walls to give me a bit more working time).
Ensuite - using marmox showerlay, marmox boards, waterproof tape, Devi-mat/SLC, then similar tiles with matching 5cm mosiacs for showertray.
Currently deciding between Ardex or Mapei grout, plus whether any additional tanking is needed.

Is that everything, never done quite so much preparation before, but wanting this to be a good job.

D

 

[AliGage]

Wow. Far too much to read through whilst on a smoke break. Will catch up with this when home this evening.
Im sure someone will answer before that happens though. Welcome to the forum.

 

[bugs183]

Sounds good to me DDD!
That will serve you well, as for the good old 6mm ply, why do they keep using it :mad2:

 

[AliGage]

Just had another read. Sounds like you've been quite thorough with your homework. All sounds good to me.
Make sure that tray in the en-suite is well supported and i know you're using marmox but id tank the wet areas for sanity purposes if nothing else.

 

[DDD]

Thanks, been doing quite a bit of reading. I was thinking the same about the tanking. Any particular product you would recommend?

 

[AliGage]

I use BAL or Ardex. Ardex is cheaper where i am but BAL is easier to apply and use.

 

[swanman]

good advise

 

[bugs183]

To be fair if you use Marmox use their self adhesive tape it sticks like nothing on earth!
I prefer the Mapei Mapalastic Defense, i reckon it sticks better than the Bal, but not used the Ardex.
Tape all the joints with the waterproof tape then apply which ever tanking with a short pile paint roller, it'll go on a treat and you'll have a bomb proof shower.
It's great seeing someone make the effort to do a great job!!

 

[swanman]

Ultimate flex
Is good

 

[DDD]

Thanks everyone, most of the stuff now on order, hopefully delivery won't take too long so I can get on with the work. Just got to find those elusive stainless steel screws - local shops trying to charge an arm and a leg for them. Am I right in thinking I need 4mm screws x length depending on substrate (30mm for floor, maybe long for wall). I've not got the washers yet and nowhere actually tells you the diameter needed