Crumbling plasterboard in shower (SBR?)

[brian0123]

My question is: can SBR be used to “restore” crumbling plasterboard behind shower tiling?

If not, what else would you suggest, please?

Tiles have popped up in a smallish area (110 cm 40 cm) of the shower due to water getting in behind them. The standard foil-backed plasterboard has consequently cracked and gone powdery but looks salvageable, i.e., no actual holes.

My idea is to consolidate the loose material with SBR – hoping it would work like wood hardener. Then to use a waterproof compound like Sika Aquaseal, then refit the old tiles.

Will this work, do you think? If, so, should I dilute the SBR for greater penetration?

Professionals would probably say rip it all out and use Hardibacker or similar (and they’d be right) but, you know…

Very many thanks for any thoughts.
Brian

 

[foxhole]

Follow the pro advice, a bodge won't hold.

 

[dontbelieveawordofit]

start again

 

[brian0123]

Apologies for these late thanks, foxhole and bennymultifish.
Update: project on hold.
I experimented with SBR as described above: neat, 1:1 and 1:2. Neat works best as the plasterboard seems firmer.
I'll probably have a go as I'm curious and the area to be done is small. The pros will be called (of course) if it doesn't work.
Thanks again.
Brian