Tiling MDF floor & repairing plasterboard walls

[Tel77]

I've just joined up in the hope I can get some tips with a new project that I have just started in an en-suite room.

I'm still in the process of removing tiles and some of the plasterboard has broken away so wondered if there's any special requirements when I come to replace it?

I'm also planning to tile the floor which is made up of sheets of MDF which i realise I shouldn't tile straight onto but wondered what sort of thickness marine ply I can get away with using as the floor is sturdy with no flex in it anyway?

 

[tpt]

your right about not tiling directly onto it. its an unusual surface to find! main prob is its lack of resistance to water and i honestly wouldnt trust it. i'd advise taking it up and using 18mm ply (depends on the gap between your joists etc - have a search in old posts in here)

If you have no choice but to go ahead AND there is no movement\deflection (use the two fat blokes test!) then i'd look at using a backerboard.

Another problem with MDF is it doesnt hold a screw too well so whatever you fit over the top isnt going to be great as they all have to be screwed into the base

 

[Richard C]

I've just joined up in the hope I can get some tips with a new project that I have just started in an en-suite room.

First tip is Read the Tiling Forum sticky & archive posts

I'm still in the process of removing tiles and some of the plasterboard has broken away so wondered if there's any special requirements when I come to replace it?

In a wet area only replace with waterproof tile backer board; dry areas use moisture resistant plaster board but if you need to plaster anywhere it must be primed first.

I'm also planning to tile the floor which is made up of sheets of MDF

In no way should you tile onto MDF if that’s what you have; unusual, are you sure your not confusing it with chip/crap board?

which i realise I shouldn't tile straight onto but wondered what sort of thickness marine ply I can get away with using as the floor is sturdy with no flex in it anyway?

If you’ve got MDF or chip on the floor, there is little point in over boarding IMO, you will need a minimum 12mm WBP (British Standard is 15mm). Far better to rip it up & replace with a decent floor more suitable for tiling; it won’t cost much more but will involve you in extra time. Use WBP ply (you don’t need more expensive marine ply), 18-25mm thick; exact thickness you need will depend on the joist size/pitch/span you have. You must seal the back/edges with acrylic primer but not the tile face. Read the archive posts & all should become clear, post back questions as & when you need to.

 

[big-all]

mdf is never ever an accseptable floor it sags it dosn't like damp basically its like useing thick cardboard for flooring