MDF tongue and groove panelling in bathroom

[EleanorAlice]

Hi everyone we are installing MRMDF/moisture resistant mdf T&G panelling on 3 walls of our bathroom floor to ceiling, they are 2 new stud walls and 1 single skin brick wall with old plaster in bad condition.

We are having plasterers in for elsewhere, but is there any point plastering the walls which will be covered? Can they just be attached to plasterboard? Most online content suggests so, though we saw a caution that the adhesive from the mdf could sink into fresh plasterboard? My boyfriend thinks there is a benefit to plastering anyway, but I see little point if the adhesive would ruin the surface of the plaster.

And secondly, what would you recommend for wall with existing (falling apart plaster).

One final question, we're planning to use the panelling around the bath like the picture below. All the mdf will be cut to size and then spray painted with a solvent based paint to waterproof it. Do we need to spray the hidden parts of the mdf too, or can we waterproof as effectively with varnish?

Thanks so much for any help!

 

[theflyingpig]

I think I would remove the plasterboard and fix the mdf directly to the studwork. And on the masonary wall... I'd remove the plaster for sure - is this an external wall? .....

 

[EleanorAlice]

Thanks! Yea its an external wall

 

[foxhole]

You cant waterproof MDF , it will eventually fail if used for a bath panel. If
Paneling will stick easily to plasterboard and your brick wall with right adhesive.

 

[Deleted member 174758]

I can't think of a worse product to stick on a bathroom wall! It will act like painted blotting paper - even the MR variety won't last that long