Suitable adhesive for tiling upstairs onto ply?

[joshtiler]

Hi all, I recently read a very long thread about tiling onto chipboard floors in upstairs bathrooms and how it is not a suitable surface to tile onto. Now i make sure that all chipboard is overboarded with ply and firmly fixed. Was just wondering what adhesives are suitable for tiling onto ply and do i need a single part or 2 part flexi adhesive? Also what is the best primer to use for ply?
Many Thanks.
joshtiler

[TIP TOP]

hi rich,i use a kerakoll product called marmorex which is a flexible powder but on timber i will always use the top latex with it as a two part mixture.you should use an acrylic primer but i like to use a tanking paint called aqua 77 which seals and totally waterproofs the ply,i dont know what the other guys and gals out there do.hope that helps

[Dave]

Hi Josh, personally i try to avoid tiling direct to ply, yes there are plenty adhesives that will bond directly to it but for extra moisture stability , i like to overboard with min 6mm cement type boards.. i,e. hardibacker 250..

This gives me and my customer peace of mind that water ingression doesn't hinder the bond of the tiled installation..

[joshtiler]

Thanks for answers guys

Dave: I have never used hardibacker 250 before what do you fix it with? the carpenter has already put ply on the floors so is it ok to put the hardibacker onto the ply? does the hardibacker need priming? will i need a spf or 2pf adhesive to tile ontop of the hardibacker?

[Bri]

Hardie is stuck with SPF and screwed every 200mm. Just out of interest, how thick is the ply that's been laid?

[joshtiler]

Hi bri, i think its 15mm ply thats what i asked for as saw a tread on here that said 15-18mm is that ok? thanks for the fixing instructions, will i be able to use the same spf adhesive to lay the tiles? does hardibacker need priming?

[ROBSON MCGREGOR]

Hardie is stuck with SPF and screwed every 200mm. Just out of interest, how thick is the ply that's been laid?

What screws do you use for fixing the hardie & do you also use washers?

[Rich]

As has been said above, ply is better than chipboard but is still not a good substrate to tile onto, a cement board would be my choice. If you do decide to tile directly to the ply then I would recommend a 2-part adhesive and make sure that the ply is fixed correctly. Have a read through the link below for a little bit more info



Plywood floors...