painting over new plaster issue

[AshleyC]

Ok i had by bedroom ceilings skimmed over a couple of weeks ago to cover the artex up. I've put a water thinned wash of white on as the base coat but in one of the rooms im getting dark spots appear all over it. Looks like little mould spots! I think its the PVA of the base coming through the plaster. The artex was especially thick and pointy in this room and it gave the guy a bit of hard work, i think he put extra PVA on there. So i've added another base coat of an unthinned oil based paint as that's what people have suggested but the spots are still showing through, not as bad as before but they're there!

What can i do to sort it out. I don't want to paint it all over now and then in 3 or 4 months i get the spots coming back. Is there a solution to this other than a tonne of paint layers?

 

[Nod]

Plaster will take a fair while (think several weeks rather than a couple) to dry out completely and the moisture that needs to escape can only get out through the down side. You can get special paint for fresh plaster which allows the water to escape better than it can through watered down emulsion and a full strength coat of oil based paint is probably the worst thing you could have put on it since that'll seal the moisture in completely. Not sure what the answer is other than start again and be more patient.

 

[Astraeus]

Be more patient.

As part of our renovation, we had every wall dotted and dabbed. Those dark patches showed wherever there were dots of plaster beneath the plasterboard. It appears that there was more moisture retained in the parts of the plasterboard where there was also plaster behind it whilst the other parts with air behind had dried out.

We put paint on about 10 days after the plasterers left.

 

[munch]

Ok i had by bedroom ceilings skimmed over a couple of weeks ago to cover the artex up. I've put a water thinned wash of white on as the base coat but in one of the rooms im getting dark spots appear all over it. Looks like little mould spots! I think its the PVA of the base coming through the plaster. The artex was especially thick and pointy in this room and it gave the guy a bit of hard work, i think he put extra PVA on there. So i've added another base coat of an unthinned oil based paint as that's what people have suggested but the spots are still showing through, not as bad as before but they're there!

What can i do to sort it out. I don't want to paint it all over now and then in 3 or 4 months i get the spots coming back. Is there a solution to this other than a tonne of paint layers?

You may have sealed in the moisture by using an oil based paint.

 

[kendo1]

Patience...

 

[scottduffy]

I had my whole house replastered when I bought it three years ago. Gave the walls only a few days to dry and painted it with mcpherson trade paint and haven't had any issues at all. I've used this paint for years and usually it only takes one coat but this time it was two but it went on easily and remains mark free. Great stuff.