Painting on plaster

[Chris Styles]

Dear All,

Last night i put a skim coat of plaster on a bare plasterboard ceiling (about 3mm thick). Everywhere on the web seems to suggest that I dont paint this for 4 weeks. Seems a bit extreme.

Can anyone advise when I'd be safe to paint this (i am hoping 72 hours would be okay, i.e. this Saturday :-)

What are the problems in plainting it before 4 weeks? Can I reduce this 4 weeks as it is only a thin coat and should dry quickly? If there any preparations that would mean I could paint it sooner?

Cheers

Chris

[Rembrandt Kuipers]

How difficult is it to apply a smooth coat? I have a ceiling that I have tried to get as even as possible using jointing compound. (It has not been painted yet.) It took quite a lot of effort and looks pretty good to me, but not all the edges were tapered and inevitably it is not perfectly flat. Should I attempt to put a thin coat of plaster on?

I do not know the answer to your question - sorry. :)

Rem

[Andrew Gabriel]

That may be in the case of a full scratch and finish coat. For just a skim, I would think you would be OK to wait for the plaster to dry out (go back to light colour) plus, say, 24 hours to be safe. Ventilate well to aide drying out.

You can buy paint which is intended to be used on plaster which may still be giving off moisture. You could probably get away with ordinary matt emulsion, with first coat diluted to maximum extent allowed (probably 20-25% water). For any other paints such as silk/vinyl or special kitchen/bathroom paints, you are going to have to wait for the plaster to be completely dry first, or the paint will likely flake off.

[r.rain]

I've always painted new skim coat plaster just as soon as it dries and goes a lighter colour. I have *never* used anything other than plain old Matt emulsion and never had to water it down to seal it first as sugested many times on this forum.

Cheers

Richard

[Michael Mcneil]

3 days is the minimum for a new build. If the wall is still damp, the paint will not key. In a dry summer where you can have the heating on all night, the rest of the house is dry and you are able to vent it well, I'd still leave it 2 or 3 days if possible.

As soon as it is dry you can paint it with trade emulsion but if you want to use a quality emulsion such as B&Q or MacPherson's you aught to leave it alot longer. With trade paint you will have to put the quality stuff on in six months time as it just comes away like dust eventually.

Concerning th esecond poster. You trowel a well finished wall about 6 times IIRC.

1 Put it on 2 Wipe it off 3 Put another layer on 4 Wipe that off 5 Catch it going off and go over it with water and a light trowel. The idea of this is to get air out of the mix put in when the powder was mixed with water.

Tea break

6 Polish all the pits and streaks out.

7 Go over it with sand-paper because it is too highly polished for painting.