Fresh plaster - how many mist coats?

longwalks1

we are due to begin painting our downstairs after it was plastered, how many mist coats will it need? I hear so many conflicting opinions. So far been told:

mix of PVA, then top coat (ruled this out straight away)

1 x mist coat 50/50 paint/water split, then top coat

2 mist coats, 50/50 then 75/25 paint/water then top coat?

Whats everyones preferred, or what will give the best results please?

TheCyclingProgrammer

Tub of screwfix bare plaster paint, two coats with snagging in between. No mess or trying to the mix of water and paint right, no fuss.

You are right to avoid PVA.

Grenage

I would use a bare plaster paint, or a cheap emulsion with 50% water - whichever is cheapest.

Like Cycling, I'd also just use two coats.

Davesnave

1 coat bare plaster paint + two fine roller top coats here.

No issues.

Nick_C

Two mist coats of 50/50 followed by a single top coat has worked well for me. That's for ceilings. I guess a wall might need two top coats

Aylesbury_Duck

Agree with all the above. Had a lucky escape many years ago when a plasterer advised a much more naive me to use a PVA mix before painting. I did just that and then painted it and fortunately never had any problems but plenty of others have.

Ebe_Scrooge

I'm shortly going to be in the same position of painting on bare plaster, so thanks for the advice posted here and other similar threads.


I realise the PVA option is not recommended. Purely out of interest - what's the reason it shouldn't be used, and where did the idea of using it come from in the first place ?

Grenage

It's normally used before plaster skim, but you don't want it on the surface as paint may not stick very well.

Aylesbury_Duck

It is often said that it provides an impermeable barrier onto which the paint will adhere rather than soaking into the plaster. That works both ways though. You will also seal in any moisture left in the drying plaster which would cause problems.

Ebe_Scrooge

Thanks both - that makes sense now you've explained it :beer:

Ruski

If it is in a damp atmosphere if will reactivate the PVA and you will end up with 'crazed' paint - and it's an utter hctib to sort out

HTH

Russ