On 5 Oct 2004 14:08:54 -0700, (william) wrote:

Hi
I'm looking for some opinions on using cement based adhesive on gypsum
plastered (skimmed) drywall?
I'm doing my first paid tiling job (for a family member) she got all
the material the supplier knew where the tile was to be fitted
(plastered drywall) he supplied a cement based powdered adhesive
It says on the bag "not to be used on gypsum based plaster" I asked
him about this and he said its fine to use it he has sold tons of the
stuff and never had a problem.
My sister in law (the client) is happy enough to use it she says he
should know what he is talking about, as it is his job.
To make things worse there is a shower that is to be tiled and the
substrate in the shower area is skimmed plasterboard (he says it is
perfect for this as it is a flexible adhesive).
I want to use ready mixed adhesive but am a bit unsure because the
walls are studded walls not solid block walls and they will move a
little.
The supplier thinks I'm a donkey and my client thinks I'm over
reacting.
But it says on the bag it's not suitable.
And I have researched it on the web and found something about some
reaction between cement and gypsum.
Should I just do the job with what he supplied and keep my opinions to
myself?

Hi,

Can you get the phone no. of the manufacturer from the bag or look it
up?

Or this might give an answer:

http://www.tiles.org.uk/help/answer-gypsum.shtml

more leads:

http://www.google.com/search?q=site%3A.uk+gypsum+plaster+tile+cement

cheers,
Pete.