Tiling on a skim - devil float it?

[GotWood]

Evening all,

I need to pick you brains please.

When skimming a bathroom wall in preparation for tiling, I over-polished it and the primer (BAL APD neat) peeled off in sheets. I now intend to peel it all off and re-prime with a 1:1 dilute.

Should I then give it a second coat, neat?

Also, should I have devil-floated the skim?

Once primed, I intend to tank it (WP1) and then tile it (White Star or SPF).

I would be very grateful for your inputs.

gw

 

[gcol]

Best thing to do at this stage is e-mail BAL technical department and get something on record before you go any further. Tell them what you've done and what you've found. Follow their advice and see what happens. You can follow advice on here that may be the same advice as the BAL guys and it may still go t*ts up, but if you don't have anything documented it will be more difficult should you need to start shouting at someone.
How did you find it peeled off in sheets - I mean why did you pick at it?
My advice would be to rub at it with a wire brush (don't go mad) and start again, but strongly advise you to play the BAL game.

 

[GotWood]

I realised it peeled easily when I pulled some masking tape of it - it pulled a whole big sheet off. It peels just like you are removing PVA from your hands, I certianly have no faith in it holding tiles.

I'll try and get some advice from BAL and will report back. In the meantime, all advice/experience is welcome.

 

[tictic]

hope it small lightweight tiles your fixing onto that skimm coat....
have you left it long enough for the finish plaster to dry out.

 

[Richard C]

You should never plaster skim a wall your going to tile, let a alone polish the death out of it. If the tiles weigh in at more than around 18 kg/sqm, your going to be in real trouble & the WP1 won’t help either; what size/weight type tiles are you laying?

I would advise you read the Tiling Sticky & Forum Archive posts before doing any more work or buying materials, it could prevent you making more disastrous & potentially expensive mistakes. It’s also important to use only quality trade tilling materials of the correct type for your tiles & tile base; cheapo own brand & DIY stuff is mostly crap.

 

[GotWood]

An update - I spoke to the nice guys at BAL who advised on sanding it back (to remove the peeling primer), and priming it again with a 1:1 dilution. I did this, and to remove the dust I brushed it and then wiped clean with a damp cloth. I left it to dry ad then applied two 1:1 coats.

18hrs later and curious as to whether it was better than before, I took a small piece of duck-tape and stuck it to the wall. The tape came off easily along with the primer. I repeated the test, this time pulling the down (i.e. sheering force) to 'simulate' the tile's weight and it seems OK.

Do I still have a problem??!! Is the Duck-Tape test an over-kill? Is there a better test?



Richard C - before skimming the wall was very uneven, so I saw it as a necessary evil. My tiles weigh 18 kg/sqm. I am only using BAL products so the only weakness should be my workmanship(!).

Once again, I would be very grateful for advice.

gw

 

[GotWood]

Merry Christmas