tiling onto hardboard

[ruddyuseless]

I would appreciate some advice. The hardboard on my bathroom floor is a bit messy/dusty after tiling the walls. Do I need to prime it with something before tiling? Thanks.

 

[gcol]

First off - are you sure you've got hardboard down? I've heard people refer to plywood as hardboard before now. Hardboard is about 3mm thick and like a shiney cardboard (on one side).
You don't want to be tiling onto hardboard.

 

[ruddyuseless]

Yes. Most of the floorboards have been ripped up and replaced with 18mm ply. But in one part near the wall the original floorboards remain as they go under the wall and there was no joist to fix the ply to. On top of all this hardboard has been screwed down (rough side upwards) so it covers the entire bathroom floor.

 

[Bowness72]

I would take up all the hardboard and replace with ply otherwise any floor tiling you do will probably crack/lift and be a waste of time.
You might be able to treat the existing area of floor boards with something and tile over if its not too big an area, although a professional tiler might want to correct me about that.

 

[gcol]

You won't get anyone advising you that it's ok to tile onto hardboard. Generally in that situation you would cut the floorboards flush with the skirting or wall. Screw extra supports (noggins) between the joists and lay ply over that. You'll need support under the joints in the ply too.

 

[ruddyuseless]

Thanks, I'll give it a go.

 

[Bowness72]

You won't get anyone advising you that it's ok to tile onto hardboard.

Sorry gcol, I didn't mean tile onto the hardboard, just the small area of tongue and groove boards, assuming they are well fixed down and in good nick. Although I do agree with taking the T & G up and installing noggins. Just thought might be a bit easier if there was something suitable to treat them with.