On Sat, 28 Apr 2012 07:47:05 -0700 (PDT), alamaison
wrote:

Depends on ambient temperature etc. but generally 4 - 6 weeks.

I'm wondering whether we are all talking about the same type of
plaster?

I've only ever plastered on top of an already plastered wall or fresh
plasterboard. In theory, it should only be 3mm thick. Can it really
take 6 weeks for that to dry out?

I've never had to plaster a base coat onto brickwork. If you do, do
you allow the base to dry first or just put the finish on top straight
away? I'm thinking that the depth of plaster (base+finish coats) will
be significantly more than 3mm, and would take longer to dry, in which
case 4-6 weeks may be reasonable. So does it depend on application?