tiling on plywood

[Daniel]

Hi guys, today I will speak to client about material list needed for her three bathrooms. She wants me to do just the tiling everythings else should be prepare for me. The trouble is that when i was there last time to give her quote I noticed, that her builders boarded up the walls with 12mm play even in the shower area. She wants me to do the tanking at shower area. Question is. Is the Mapei Aquadefence liquid going to stick to playwood? and also would You tile on playwood at all? Well, If she wants it, what can i do? Last question: is here in Uk simillar agency like NSAI, the National Standards Accreditation Agency in Ireland??
Thanks Dan

 

[peteablard]

Can it not be removed and replaced? Personally I wouldn't want to tile it.

 

[Daniel]

will speak to client this afternoon, I don't think she will want to replace it. I thought adding 12mm hardiebacker boards might help, but don't know if she want to spend more money. Would tell client, that removing is the best think to do?

 

[Bubblecraft]

I'm with Pete. Advise her why it shouldn't be tiled & what would be the best option. You really don't want your name linked to it if it fails due to bad prep

 

[peteablard]

I'm sure if you explain the situation why ply isn't a suitable substrate (Not great in any areas but certainly not in bathrooms), for peace of mind it will be worth them having the job done properly

 

[The D]

BRITISH STANDARD 6.2.4.2
Sheets and boards
Sheets and boards include the materials listed in
6.1.2.6
, except
plasterboards; sheets or boards should be adequately braced to
provide a rigid surface, be free from any springiness and surface
undulations and undergo no subsequent distortion during and after
completion of the tiling. Wherever possible, the boards should be
screwed, not nailed, to the supporting framework.
In general, where the sheet or board has a smooth and a rough side,
the latter should be used for tiling. The surface to receive the tiles
should be clean and free from dust and other forms of
contamination.
The use of sheets and boards that are subject to movement from
changes in moisture content, e.g. wood-based materials such as
plywood, chipboard, wood particle boards, etc., should be avoided if
at all possible. If such boards have to be used, they should be
restricted to small areas and tiles should not bridge joints between
boards. All exposed edges and the backs, but not the faces, of such
boards should be sealed with a suitable sealer to prevent distortion
by atmospheric humidity changes. Care should be taken to ensure
such boards are not installed in a condition where their moisture
content is higher than the ambient equilibrium moisture content
once the tiled installation is in use; failure to observe this can lead to
subsequent warping and distortion of the boards with consequent
cracking and delamination of the tiling.

 

[peteablard]

BRITISH STANDARD 6.2.4.2
Sheets and boards
Sheets and boards include the materials listed in
6.1.2.6
, except
plasterboards; sheets or boards should be adequately braced to
provide a rigid surface, be free from any springiness and surface
undulations and undergo no subsequent distortion during and after
completion of the tiling. Wherever possible, the boards should be
screwed, not nailed, to the supporting framework.
In general, where the sheet or board has a smooth and a rough side,
the latter should be used for tiling. The surface to receive the tiles
should be clean and free from dust and other forms of
contamination.
The use of sheets and boards that are subject to movement from
changes in moisture content, e.g. wood-based materials such as
plywood, chipboard, wood particle boards, etc., should be avoided if
at all possible. If such boards have to be used, they should be
restricted to small areas and tiles should not bridge joints between
boards. All exposed edges and the backs, but not the faces, of such
boards should be sealed with a suitable sealer to prevent distortion
by atmospheric humidity changes. Care should be taken to ensure
such boards are not installed in a condition where their moisture
content is higher than the ambient equilibrium moisture content
once the tiled installation is in use; failure to observe this can lead to
subsequent warping and distortion of the boards with consequent
cracking and delamination of the tiling.

In my head that's exactly what I was thinking Deano, I just couldn't quite put it into words like that

 

[Daniel]

Deano you are the man. I will read this for her. I think this will make change her mind. Just hope the builders won't stone me to death.

 

[nybor62]

as all above .

 

[carlthetiler]

i did a job for a local building company and the same thing had happened. told them it is not advised to have ply in a wet area due to expansions, load bearing etc. tanking kit applied, was told to crack on and 2 weeks later the ply had blown and basically it was a floating wetroom! concrete board is a must if you ask me, i refuse to start work if i know i will have to go back to the job or i am not satisfied with the spec.................spend more money getting the job right or save and spend more money getting it right!

 

[Daniel]

What do You think? Ofcourse PLAY will stay and what is worst and I started laugh when they told me, that all walls in three bathrooms 90msq were boarded with 12.5mm white plasterboard. When The designer(man who i work for occasionally) told them to rip it all off and boarded with 12mm marine play. I don't know if I can write his company and his name here, becouse it's his mate who I deal with. Well I strongly advised client not to tile it on play and she said, it's too late now anyway!!! She wants me start on 1 March. I still have some time to decide, but considering I didn't lay any tile since New Year. I have to take it. All I can do is take pictures and let her sign piece of paper that She was advised not to do it. will post pictures of final product. Thanks guys for help.

 

[beanz]

Whilst not being perfect, i'd have thought Marine Ply would be ok, as moisture shouldn't get into it. At the end of the day, you can only advise them. Tell them you'll tile it, but can't guarantee it, as your insurance wouldn't pay out if there's a fail... Might make them think.

 

[John Benton]

We've had quite a lot of posts on here about tiling onto unsuitable substrates. The thing is, this can be put right before a tile has been fixed.

As has been said before, asking the customer to sign a piece of paper and you not to accept any responsibility when you know it is the wrong thing to do counts for nothing.

If you do the job and it fails, it will be your phone ringing, and it will cost you more to fix than you got paid.

So, in my opinion, that's not the way to run your business and I would insist that it be changed to a suitable background or not do the job at all.

 

[Daniel]

Thanks John, you are right about the responsibility.

 

[peteablard]

Print this thread off and show the designer.... If you are going to do it then get the customer to ask the designer to sign a disclaimer. He's the one saying it's suitable when it isn't and he's the one who the customer needs to turn to when it goes wrong. Ultimately though you really shouldn't do it. I can almost see the new thread appearing on here in a couple of months, "My tiler tiled over ply when he shouldn't have done and now the tiles are cracked...."