Tiles aren't sticking to marine ply

[GCarnegi]

I have just tiled my bathroom using B&Q's own premixed adhesive/grout for bout £18 a pot.
I also built a small 3ft square "plinth" behind the sink - something to screw the sink to and forming a three inch deep "shelf" bhind the sink for the wife to put her soap on - us men don't use soap!

Anyway, the front of this plinth is made of marine ply, and I tiled it last night for the plumber coming round today to plumb in the sink. Thing is that the tiles are just falling off the marine ply really easily - okay I had to pull them a little. But this is after 12hrs, I'd have though the adhesive would have been dry by now?

The adhesive behind the tiles can still be scraped off like some kind of dry powder/paste. Kind of like it is when used on plasterboard after about 5 minutes.

My question is will this eventually dry and hold my tiles firm, or should I use some other adhesive for marine ply?

The ply isn't flexing at all (it's 12mm thick and it's vertical so there's not any flexing stress on it)

Interestingly, the tiles are ALSO not sticking to the top or side of the plinth, which are just the bare CLS timber (2x3's) - I plasterboarded ONE edge of the plinth as it's next to the bath - those tiles are absolutely solid.

any ideas?

Best regards
guy

 

[nellyb]

Without knowing what sort of adhesive you've used, it's difficult to say what the problem is. Does it say whether or not it is suitable for fixing to timber surfaces? Did you prime the timber with the required primer?

For fixing to timber, you should use either flexible/polymer modified powder adhesive, or a GOOD QUALITY ready mixed adhesive specifically designed for bonding tiles to plywood.

At the risk of repeating myself use a proper tile shop and not somewhere like B&Q. That way you get the right advice in the first place and will probably pay less for the stuff you buy also.

 

[gcol]

If you shop at B&Q, get a tub of Cerafix Trade tile adhesive. Don't use B&Q's own. And never use adhesive and grout in one. Always use a powdered grout that you have to add water to.

 

[GCarnegi]

Thank you very much for all your assistance.

Out of interest, the timber has not been primed or treated with anything (unless maybe there was any preservative added during manufacture).

I have a different adhesive for the floor tiles (it says its especially for use on floorboards). Maybe I'll try using that instead. It's pretty sloppy to apply, but seems to stick like sh^t on the floor. Unfortunately it's grey, but I'll be able to use the same grout as I used on the walls so no big deal (I hope!)

all the best,
Guy

 

[warehouseman]

Nellyb was spot on.
You are asking for trouble getting most materials from B&Q. The adhesives are normally 'budget' & of inferior quality.
Its advisable to PVA any ply as otherwise the liquid in the adhesive will partially soak in & there will be limited adherence.
Secondly, it is imperative that the adhesive is FLEXIBLE. If in powdered form, you can buy a good one part flexible adhesive in an independent store . They will help you & know what theyre talking about. If you use a ready made tub adhesive (flex again), it will be slow setting (min 24 hours) as opposed to 3 hours for fast set adhesive.
Incidently, a lot of powdered adhesives say they are suitable for wooden tiles BUT some are not flex & so you need to put in a flexible additive.
If you have stuck tiles with a non flex adhesive onto wood, sorry, but sooner or later they will start to drop off !!

 

[gcol]

Its advisable to PVA any ply as otherwise the liquid in the adhesive will partially soak in & there will be limited adherence.

I'd use pva only when wall tiling or tiling on a bath panel using a pre-mixed adhesive. When flooring, if you use a decent powdered flexible adhesive then pva'ing the ply boarded flooring is not unecessary and not recommended.

 

[sparkman]

Don't use B&Q for your needs - use a reputable trade tile supplier - you get free advice and the products are not only better but cheaper.
I made that mistake when tiling my new extension - I used a B&Q flexible adhesive (on their advice) onlt to find that after two weeks the floor tiles were still loose - the whole kitchen, dining room and conservatory floors had to all be taken up and B&Q didn't want to know when I complained.

sorry this sounds like I have a downer on B&Q - I haven't - just prefer to use trade people rather than diy sheds.

 

[Moz]

powdered mud/adhesive an grout only ...can be guaranteed IMHO

check here Bal ......ARE THE BEST

http://www.bpindex.co.uk/manf.html?id=1060

never assume that all mud/adhesive products adhere too PVA walls/Plywood as they DONT ....trust me ..lol

 

[abalone]

what is the best tile adhesive to use on VARNISHED chipboard? I tried some B and Q flexible tile adhesive for wood but it wouldn't stick