Consistency of Plaster

The walls are made from 50 year old plaster board. They are not very absorbent -

the plaster test remains damp for over 5 mins.


I have been making my mix to the same consistency as my Joint Filler - is this too thick? I am finding it difficult to spread. What would you say an ideal mix should look like?

Answer

Plaster Consistency
The Plaster should peak slightly when you pull the whisk out of the bucket, kind of like a thick yoghurt - so perhaps you could try it a little thinner. It should be easy to spread but you may instead find it harder to control when loading up your trowel.

Plasterboard Walls
Rather than just be damp, the plaster should be quite 'fluid' still for at least 5 minutes or longer if on a larger wall. Applying a coat of PVA to the plasterboard will make it less porous and therefore ensure the plaster remains workable for longer.