tiling on a wooden floor

[hairymary]

hi fellas im about to tile my kitchen floor which i have prepared with 12mm wbp ply screwed at 300mm centres. I intend to use BAL SPF Adhesive but i have read on another forum that i should have primed the underside of the ply? Is this correct?

[hillhead]

thats correct,and the edges too for extra peace of mind.whats your subfloor? under your ply?12mm could be too light depending on sub again.

[diamondtiling]

I agree with Joe regarding the 12mm ply, any deflection on that floor will result in the tiles lifting. I would insert extra noggins for strength and use 18mm ply over the existing joists.

[hairymary]

my sub-floor is t&g. I have a problem with regards to priming the underside of the board in that the board is already down and the new kitchen units already installed over it!

[Alan.P]

What's the t & g sitting on, I'm assuming wooden floor if you've fixed at 300mm centre's, on that note, how do you know you've screwed into joists ? You've more than likely gone into the boards. It does sound like you may well have problems in the future if you don't get the preparation right now, and to be blunt, it sounds like it's not right sorry.

[timeless john]

Replied to your other post!
For the answer on this post - I would recommend that you overboard the 12mm plywood with 6mm Hardi Backer Board or similar.
By cross jointing the boards you will not only provide a waterproof surface, you will stop the direct transfer of movement through to the tile.

[muffinman]

hi fellas im about to tile my kitchen floor which i have prepared with 12mm wbp ply screwed at 300mm centres. I intend to use BAL SPF Adhesive but i have read on another forum that i should have primed the underside of the ply? Is this correct?

prime the surface and edges of the borad use 18 mm ply ,why prime the under side of the board tip wen srewinf down dont use long screws ,they need to be shorter then lenth of the ply and the floor board take my advice you may hit a pips ahesive needs to be flexible I uesd a webber product with AD250 and primer T

[Alan.P]

prime the surface and edges of the borad use 18 mm ply ,why prime the under side of the board tip wen srewinf down dont use long screws ,they need to be shorter then lenth of the ply and the floor board take my advice you may hit a pips ahesive needs to be flexible I uesd a webber product with AD250 and primer T

The underside and sides of the boards are primed to stop any ingress of water into the boards that could cause warping of the boards witch will pop the tiles.

[hillhead]

Ditra matting might do the trick,i used it this week over 22mm shuttering grade ply just to protect my tiling !!!!

[bluebob]

i would put a few more screws in.150 centres and change to a 2 part flex.unless there is obvious movement you should not have any problems.

[bluebob]

forgot to add,or take timeless johns advice.either way you should be ok

[muffinman]

sorry guys why should you primme the undersurface joke there is no damp there if you guys are looking for advice then look ere

[diamondtiling]

sorry guys why should you primme the undersurface joke there is no damp there if you guys are looking for advice then look ere

Come again chuck???

[hillhead]

This place is getting funnier.lol

[diamondtiling]

I suspect muffinman had a few beers when he posted that Joe. When he reads it later it will be, "Doohhhhhhhh!!!!! did I really say that"

[grumpygrouter]

prime the surface and edges of the borad use 18 mm ply ,why prime the under side of the board tip wen srewinf down dont use long screws ,they need to be shorter then lenth of the ply and the floor board take my advice you may hit a pips ahesive needs to be flexible I uesd a webber product with AD250 and primer T

BAL don't specify priming the tiling surface of ply with their adhesives, and as per Alan P for why you prime the underside.