In article ,
"Man at B&Q" writes:
On Dec 18, 3:19 pm, (Andrew Gabriel)
wrote:
In article ,
Tim Decker writes:

I have had to re-plaster part of my shower room. This is about 25mm
thick and was done using browning and then finish plaster.
I am assuming that I need this to dry completey before I plaster. Once
this is done I should prime the surface.

I have read conflicting advice on this. The tiling faq

http://www.enigmatist.com/free/john49/tilefaq.htm
recommends the use of pva.

However, elsewhere I have read that this can cause problems if it gets
wet.

I would be interested to hear the views of the group on this.

You have to check the instructions for the adhesive you use.
None are likely to recommend PVA as it's water soluable,

Except when it's waterproof?

Waterproof/Exterior PVA (which is really EVA) is only waterproof
inside a mortar mix (and it's only a bit more waterproof than PVA).
Other than that, I'm not sure what you're referring to.

If you want to create a waterproof barrier (e.g. on plasterboard),
use one of the tanking products designed for the purpose. If you
just want a bonding agent, that's already in the tile adhesive,
and it sticks rock hard to anything (as anyone who's tried to get
a misplaced bit off will testify;-).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]