drying time

Hello, I'm wanting to follow some advice given on here (huge thank you to JohnD!) to fill in some deep gaps/holes on a Thermalite wall with a sand and cement mix. After I've filled in the holes, I intend to dot and dab plasterboard across the wall and then skim over it with plaster. Please...

I am purchasing a lower ground floor flat and we have identified that there is a fairly bad damp problem. We have had a damp specialist in and they have recommended the treatment outlined at the end of this post. They have mentioned we should give the plaster 1 month per 25mm of wall thickness...