What tile adhesive is used for large format tiles?

[White Room]

Has the plaster been contaminated with something, did any of the primer seperate when applied to the walls.

Did you upset the plasterers by any chance ??

 

[stevep1]

we started with 1-4. only went to neat as a test when nothing else worked. and on the advice of palace tech. some people say dont make a barrier between tiles and wall and others say you have to because of the plaster and addy reacting. never had it before pray i dont again.

 

[Aston]

how long did you leave the 4 to 1 ratio ? before the next coat??

 

[stevep1]

dont think it seperated. they seemed like decent chaps (for plasterers). i know the house owner went through a spell of sacking plasterers. i dont suspect sabotage though.

 

[DHTiling]

The reaction is ettringnite and it can take 2 coats etc to fully protect and as i said before if you apply neat it can skin.

I am finding it difficult to give a reason now steve as all that i use works for me ..

Your failures haves lost me.. lets see if another set of pro eyes can recommend something..

 

[White Room]

The plaster can be very absorbant so thats a good reason to prime alone other than enttringnite

 

[stevep1]

the first 4-1 coat was dry in 15 mins . i would say the next one went on an hour later

 

[stevep1]

i've lost myself. everything i've ever done before this job has worked for me too. thanks for your time and suggestions its really appreciated

 

[White Room]

Is the plaster all gypsum, as in a float and set or sand cement then a finish

 

[stevep1]

gypsum. thats why we went with palace tilers primer. it says on their web site to use it neat when sticking to gypsum with a cement based addy. since then i have tried everything

 

[White Room]

No, what I meant steve was a browning, hardwall, bonding or sand cement backing used on the block walls before the plaster finish was applied

 

[DHTiling]

Steve.. my apologies.. i am kind of slurped.. i will ,if not resolved tomorrow have another sober look..

 

[stevep1]

a 3 mm skim coat of gypsum finish over plaster board. i explained the weight issue but was told to go ahead. that wouldnt explain the tests ive done with 300mm cuts from the ceramic tiles that wouldnt stick when stood up against the wall

 

[stevep1]

i'm having a few myself. been one of those weeks

 

[Aston]

steve
how long did you leave the 4 and 1 coat of sbr? before applying the 2nd coat
just answer that for me please