Wet room floor

[Brendann95]

Hey I'm after extending my bathroom iv knocked through into a bedroom to make it one big bathroom and I'm going to turn it into a wet room. The only problem is the floor in the bedroom is 40mm lower than the existing bathroom.they are both concrete floors.just wondering what is the best way to build it up ? Would leveling compound be OK at that depth or is there a type of plywood u can get that won't swell if it got wet ? Thanks

 

[Mr diy a lot.]

So you are trying to raise the floor in the bedroom? presume its an old historic house or whatever? 40mm to much for leveling compounds - you would need loads of it too!
if you really want to raise the floor then ply or chipboards if what you need glued down to floor. ply would only be getting wet if your wet room was a botched job! - but marine ply better water resist properties.