First floor wetroom / underboarding - yes or no?

[SJRSJR]

Hello

Just reading up on wetroom formers, one for the main bathroom and one for an en suite shower room. My plan was to replace the room with 25mm marine ply butting up to the former which would have an underboard as support. But having taken the floorboards up to have a look there are water pipes that mean I can't easily underboard where the former will go. I've read old posts which mentioned Tuffdec not needing underboarding but they don't seem to be around anymore. Are there any formers that can sit on joists alone?

Secondly this is is first floor - there are quite a few people who think it's crazy to put a wetroom on wooden joists on the first floor. I've already had one before and never had a problem in 20 years. Granted the tiles are smaller than what I'm planning (30 x 30).

I could maybe get away with a shower tray in the main bathroom but the en suite is very small and lends itself better to a wetroom. Advice would be appreciated. Thanks

 

[yorksbuilder]

No more ply TG4 board, put it straight on your joists. No under board needed.

They also do wet room shower trays

 

[SJRSJR]

Thanks yorksbuilder. I've looked on their website and maybe I'm being a bit thick but their trays are 28mm depth so I can't figure out how it would work with their 22mm board. (The trays need underboarding too so my problem with the pipes still exist.)

Price wise it looks to be on par with marine ply but with the boards being 1200x600 it's definitely more manageable, Will investigate more.

 

[SJRSJR]

So their 28mm wetroom trays aren't intended to go with the 22mm TG4, they're for use where you're overboarding a 22mm existing floor with their 6mm backerboard.

 

[yorksbuilder]

Yes you're right. You could put 22mm plus 6mm cement board!! A bit OTT but no leaks or movement.

Or find a wet room shower tray that works with 22mm floorboards.

OR
Use Kudos floorboards and shower tray. All marries up flush and glues together with their solvent cement. I recently used it and was impressed

Kudos Aqua4ma Evolution Centre Waste Shower Deck Kit - Relentless Microcement

Wet room shower tray deck and centre waste kit. Tested and approved for use with Microcement. Includes Waste Kit.

relentlessmicrocement.com

 

[SJRSJR]

Thanks again, will check them out