Plastering ceiling

[crapmemory]

Please settle an argument. We are having a ceiling plastered and have purchased new light fittings for the same room. Do we fit the lights before or after the ceiling has been plastered? Also, how long do we wait to paint and can we emulsion straight onto plaster or should we undercoat first?
Many thanks

[buildersmate]

After - the plasterer will want you to remove them or he'll have a hell of a job making the thing flat with the celing fitting in the way.
When it's dried out - at least a week. Similar rules as for walls - first coat well-watered down - it soaks it up like a sponge.

[crapmemory]

Thanks for that. Somebody told me that Wickes do a paint especially for putting on new plaster. Do you know if it's any good? Otherwise, what ratio of water to paint?

[theshedman]

Hi, I agree with buildersmate about removing light fittings. you will get much better finish. I would try the light fitting first though before plastering then measure where it is to go to make sure you get the fittings in the right place when you come to put it up afterwards. If you miss the joist or nogging you could end up with a few unwanted holes in your nice new ceiling. A couple of coats of watered down emulsion will be fine to seal the new plaster. The first coat should have at least 25% water put into it. There should be no need to buy special paint as watered down emulsion will do the same thing without the extra cost.

[crapmemory]

Thank you both for your answers.

[furrydice2]

Yes I agree you just need to buy some of the cheapest white emulsion you can, then water it down a little. This will seal the plaster really well. If you don't do this and you just put the paint straight on to new plaster you will find that when you come to put the second coat on it will pull the first coat off, this creates massive problems. If you use white watered down emulsion then you will see shadows where there are small marks, you can then sand these before applying the final coat of paint. This will result in a perfect finish.