Wet Room Floor Advice Please

[Chalker]

Just explain that grout is not water proof . Plywood expands. And it will fail.
Before tray formers were widely available, I worked on a job for a footballer. He wanted a large two person shower room. Again a joiner constructed the floor (very well) and a quality drain ( (Harmer) was fitted. It looked great.

Fast forward a couple of years later when the grout cracked here and there, then they could not get rid of the musty smell. Went in and removed the tiles and the whole thing had turned black with bacterial growth in the ply.
Mate or no mate, he needs educating.

 

[One Day]

This is a brand new floor being built in a room that was a boiler room Impish mate. As I said the one thing I know is that it'll be solid. Mike Holmes solid, overkill.
As stated previously, I have made him aware of all of the above and he still wants to do it his way. Nothing I can do about it. He's gone and bought a wet room linear drain and trap etc. and his plumber says it's no problem to fit so my hands are tied.
It's just another case of 'what does the tiler know' unfortunately.
EdinTiler

For the sake of our profession then - tell him he's wrong!
But it's no good telling someone they're wrong without telling them why - and then what they can do about it.
If he is insisting on HIS way then I'd personally suggest that you tank everything flat with BAL tank-it (but not from Topps - way too dear). BAL tank-it outperforms Ardex WP. Then using the same gear - fix kerdi-keba or Wedi tape etc to all joints around the drain assembly and the same on all internal corners.
photograph everything closely before you tile so that if a leak occurs - you have proved that you have done your bit.
Remember - just one slight break in the waterproofing and water WILL find it's way into the substrate. If it's timber or cement board, it will soak it up like a sponge.

 

[One Day]

Just explain that grout us not water proof .

They never believe it. As EdinTiler said - we're just tilers!

 

[EdinTiler]

For the sake of our profession, I HAVE told him and explained exactly why there could be possible future problems. It's in my best interest to isn't it.
Absolutely everything will be taped and tanked regardless with the appropriate products. Just a stress that I don't need at the moment. Apologies if I'm biting a bit.
EdinTiler

 

[EdinTiler]

@impish What would you suggest goes over the top of the plywood? I've only ever fitted the Schluter systems on raised plinths and platforms with the formed trays and membrane before. With no problems I might add. He'll be using ply regardless of what I say so anything that'll make my work as fool-proof as possible will be a consideration.
Thanks in advance
EdinTiler

 

[EdinTiler]

I learn all the time in this great trade of ours and this is something I've never had to deal with before so I do totally appreciate all advice suggestions from all of you in whatever shape or form. I'm not scared of a bit of constructive criticism either. It's just that, as I'm sure you'll all understand, if it did go **** up then it's a 20yr friendship out the window and that's not something I particularly want.
EdinTiler

 

[J Sid]

My advice......DON'T do work for a friend who thinks he knows more about YOUR trade then you do.
It will end in tears

 

[Old Mod]

Make him read this thread!

 

[One Day]

@impish What would you suggest goes over the top of the plywood? I've only ever fitted the Schluter systems on raised plinths and platforms with the formed trays and membrane before. With no problems I might add. He'll be using ply regardless of what I say so anything that'll make my work as fool-proof as possible will be a consideration.
Thanks in advance
EdinTiler

Over ply? I'd use BAL Tank-it. BAL Technical say no, but I've done tests of my own - (for a terrace build up) and it stayed bonded and waterproof even after the wbp ply failed and delaminated.
No matter what you cover the ply with, be it a sheet membrane or liquid, it's just prone to absorbing any water it can get - even damp and condensation from underneath.
If the shower is used more than once a day, I'd guess it won't last more than 5 years - and that's if you make everything watertight from above.

 

[EdinTiler]

Thank you. So what would you use for the sub-floor if not ply?
Just spoke to my mate, expressed my dissatisfaction at nor wanting to listen to me and now he is prepared to listen. Thank god.
EdinTiler