In my ongoing bathroom renovation, I want to remove the knackered plasterboard and clad the walls in painted timber T&G cladding, for a country/scandi look. My other half has asked whether that's allowed or would it breach fire regulations. Anyone care to enlighten me?

What's behind the plasterboard - a masonry wall, timber structural frame, cavity, loft?

That sappy spruce T&G does burn crazily fast, try lighting a sample and decide. It splits as it gets hot so I'm not sure paint would stay on it in a fire (or at all), and it swells/shrinks when humidity changes...

Would the little gaps along the t&g joints let cold draughts in at you as you are stepping out of the shower?

You can get quite nice moulded aqua panelling now moulded to different textures, maybe there is a suitable wood-effect option?

Posted By: JontiWood cladding is fine and something that is done quite a bit even in the UK. Better done with a denser wood which is a slower burner but whatever you chose treat it and it will meet regs.

+1

I've done plenty over the years, from high grade clear, ( no knots ) softwood to American Ash to European Oak. For a nice look, ideally go for a clear grade wood with an "open Vee" finish, paint it before you fix it, A. it's easier on the bench, B. you'll get a better more professional finish, C .it avoids nasty unpainted stripes as the wood moves and shrinks, ( it will ).
I would never use impressed MDF T&G lookalike panels in a wet room that's a no-no for me and I don't care what manufacturers say about it's suitability. Having said that, I have used them on a ceiling and to great effect. I painted them on the bench, with a roller applied 3 coat acrylic paint with a very light sand between coats and the finish was excellent.

Thanks for the advice.

Two external walls are masonry, two internal walls are timber stud.

Can anyone recommend a flame retardant undercoat? I want to have the final finish in eggshell.