Tiles falling off plywood walls - help

[benno]

Hi,
I am trying to tile a small cloakroom containing a toilet and a wash basin. The walls have been lined with 11mm plywood which has been screwed to a sub-frame, the tiles are 320X600 porceline and are 9mm thick. I have used a tubbed addhesive supplied by the tile shop and it has been applied approx 6mm thick using a slotted trowel. Some of the tiles seemed to be very loose after 2 days to cure and have come off with most of the adhesive either still on the tile or still on the plywood, but others are still firmly fixed.

My question is should I have primed the plywood, and should I have used a powdered addhesive given the size of the tiles.

Also, I will need to drill a couple of holes into the tiles, so what is the best way of doing this ?

Thanks in advance for any responses

 

[DHTiling]

Hello benno and welcome....


mmmm what a dilemma you have got yourself into....


Well, i'm afraid it is wrong adhesive onto wrong substrate and wrong adhesive for that type of tile...

Ply on walls is not a good idea to start with and i do not think it will support the weight of those tiles anyway even if you had used a flexible cement adhesive...

Ply only holds about 25kg per mtr..and that includes adhesive and grout...

You could screw plasterboard to it...and then use a cement adhesive and not tubbed stuff...

The tiles you have put on should clean up fine....but deffo do not tile onto the ply on the walls....over board if it is feasable...

 

[White Room]

Did the shop supply the tiles as well as the tubbed adhesive, the wall adhesive is the wrong gear to use for the porcelain, It's air drying and with that size tile and dry on the edges but would'nt allow air to get to the middle of the tile. I would try and remove them asap and use a cement adhesive. I would have used plasterboard for the walls unskimmed

 

[benno]

Thanks, that was quick :hurray:

I thought I would have to start again as it would be quite dangerous to leave these heavy tiles in thier current state, luckily I haven't gone above head height yet

My own fault really, I got the tiles cheap from one place and the addhesive from another place and thought the tubbed stuff would do all types - should have joined here earlier

Could I ask, What thickness of pb would I need to use and would I have to prime the plaster board with something or is it ok to go straight on?

Thanks again

 

[DHTiling]

Hi benno...

12.5mm PB and screw about every 300mm centres...and then prime with acrylic primer...

what tile shops are near you..?..maybe we can advise an adhesive that one sells for you..

 

[benno]

Hi Dave et al..

thanks for your help, much appreciated!

We have topp tiles, b&q,wickes,screwfix and a few indepenents that I am aware of locally in Liverpool

When yopu say screw the plasterboard, is there a best way of doing this?

thanks for your help, will let you know how I get on

Also, Can you suggest any good brands for primers and adhesives given my specs

Cheers

benno

 

[White Room]

You need dry wall screws with a course thread at 32mm long, It holds to wood alot better. When you fix the plasterboard over ply overlap the joints of the ply with plasterboard. Go to one of the independent suppliers who should advise on adhesive single part flexible and primer, bal apd is the one I use but there are others.