www.ultimatehandyman.co.uk

Hi there!

I am confused to what type of floorboard i've got in my bathroom and whether I need to replace it to tile some ceramic tiles.

There isn't movement when i walk around the boards and it does not seem to be swelling even though there appears to be some water marks.

Can anyone tell me what type of floorboard i've got and whether it is suitable for floor tiling?





Many thanks

Ken

18mm chipboard. No good for tiling mate. You need to overlay it with WBP ply or backerboard. Or take it up and 25mm ply straight onto the joists.

It might not seem like it but there will be movement in your floor. As the other poster said, chipboard is a poor surface on which to tile. My method would be to screw the boards to the joists at 300mm c/s, sweep the floor and wipe over with a damp sponge to remove dust. Then overboard with 6mm Hardie backerboard or No More Ply fixing the sheets with flexible cement based adhesive such as Mapei Keraquick, and screws. Then tile, again using Keraquick and finish with Mapei Ultracolor Plus flexible grout. Leave a perimeter movement joint and fill with silicone.

Secure and use Ditra matting.

How do I fix the Hardie board (cement board) to the chipboard? Screws? What type of screws?

you have to set it on flexible adhesive then use the ceramic screws that hardi supply, alternativly you could use a ditra or shcluter matting which does not need fixing just bedding on adhesive!

PS they have to be cement based flexible addys

Will they be ordinary adhesive with flexible additive?

Cheers,

Ken

-- Thu Jun 10, 2010 9:05 pm --

Where can i buy some of this DitraMat?

www.tilefixdirect.com does it but I cant add it in for some reason
www.tilehq.co.uk charges 25quid for delivery

Does anyone know where i can get it in Aberdeen?

If you use Ditra matting, remember it is an uncoupling (and waterproofing) membrane and is designed to relieve lateral stresses. It does not help with vertical stresses, ie bounce, so you must ensure the chipboard is well screwed down at 300 c/s. That usually means inserting noggins/dwangs between the joists. Without this you will almost certainly void any warranty from the adhesive/grout manufacturer.
Keraquick is a S1 rated adhesive and can be made an S2 rated adhesive if mixed with Mapei latex additive instead of water. BAL Fastflex is a similar product, both of these being the most flexible for fixing tiles onto a timber floor. Check the Schluter Ditra website for more info.