fresh plastered ceiling - how to seal it?

[eltax91]

Hi folks. We had some water damage in the kitchen while we were on honeymonn which has resulted in a new plasterboard ceiling. The new ceiling has been skimmed by the plasterer, but i was not around when he left to ask him the question:-

Do i need to seal it before painting? If so, with something special, or just mix some water with the paint? It's a kitchen ceiling so if i don't will the paint just crack when it's hot and bring the new plaster down?

[philthy]

Just undercoat it and emulsion on top.

[spdpug98]

I would do a mist coat first, this will also let you spot any imperfections in the plaster before painting it

[eltax91]

spdpug98 said:

I would do a mist coat first, this will also let you spot any imperfections in the plaster before painting it

A mist coat?

[robinhood21]

Dilute the first coat of emulsion with water.

[spikeyhead]

Take one of the blubbery mammals and place centrally in the kitchen

Insert one stick of dinamite up its arse.

Light blue touch paper and retire to a safe distance.

I do hope the RSPCA don't monitor here

[GG89]

Buy PVA and dilute it 4 parts water to 1 part PVA, roll it on and leave for 15 minutes then paint. If you don't use it, it will be fine but will use more paint, Makes it easier for you. HTH

Edited by GG89 on Monday 12th October 21:29

[The_Doc]

GG89 said:

Buy PVA and dilute it 4 parts water to 1 part PVA, roll it on and leave for 15 minutes then paint. If you don't use it, it will be fine but will use more paint, Makes it easier for you. HTH

Edited by GG89 on Monday 12th October 21:29

agree/

[MrTom]

GG89 said:

Buy PVA and dilute it 4 parts water to 1 part PVA, roll it on and leave for 15 minutes then paint.

This - I was a plasterers assistant for a summer job and did this many times.

[fieldl]

You will get wet and PVA everywhere if you are as crap at decorating as me though.
However it is worth the effort.

[Illustrious_Lou]

eltax91 said:

spdpug98 said:

I would do a mist coat first, this will also let you spot any imperfections in the plaster before painting it

A mist coat?

You do this.

Dilute emulsion 4 part paint to 1 part water and roll on carefully as it is obviously messy. This will not only help you find any areas that need making good but it will also kill the suction that you would have by just painting over by going into the fresh plaster and making a barrier. I've replastered my whole house and painted by this method, it works.

Apply at least three coats of paint once done.

Job done

[JERRYCO]

Just use new plaster paint!

[King Herald]

GG89 said:

Buy PVA and dilute it 4 parts water to 1 part PVA, roll it on and leave for 15 minutes then paint. If you don't use it, it will be fine but will use more paint, Makes it easier for you. HTH

I am amazed how 50% of decorators/builders swear by PVA as a sealant, and the other 50% swear about it.

Go on any building forum and some say it is crucial, some say it is a waste of time.

Me, I have no idea either way.

[Venom]

Having seen the effects of PVA being used as a sealant in my house, where the decorators successfully managed to throw it about on almost every surface imaginable, and the ar*e ache it's caused me in getting rid of it in unwanted locations, I'd go with the diluted 'mist' coat method personally. Much easier to clean off unwanted areas in my experience, notwithstanding other relative benefits of either approach.

[V12Les]

robinhood21 said:

Dilute the first coat of emulsion with water.

By far the best way.

[iiyama]

Mist coat with contract matt.....ie an emulsion with NO vinyl content.

[B17NNS]

Yep, as has been said, a mist coat (50/50 water/emulsion) followed by a couple of coats of undiluted emulsion.

[Dr_Gonzo]

Mist coat it with a 70/30 mix of matt emulsion and water. You may even want to then do another coat of 90/10 paint/water if it's still sucking in the moisture. The reason for the mist coat is that the plaster will be like a sponge for the first and possible second coat. If you paint straight onto fresh plaster the moisture will be drawn out of the paint too quickly and it wont bond to the surface. It may look ok but it will probably start to flake off after a few months.

Some plasterers recommend PVA but that's because they don't have to deal with the after effects. PVA will become glue again when it get wet so when ever you paint the wall you'll have liquid PVA mixing in with it. You may also get the PVA bubbling as moisture gets through the surface. In short don't use it. It's the most over-used product in the building trade.

[fatboy b]

Polycell Basecoat can be painted on bare plaster.

[GreenDog]

Dr_Gonzo said:

Mist coat it with a 70/30 mix of matt emulsion and water. You may even want to then do another coat of 90/10 paint/water if it's still sucking in the moisture. The reason for the mist coat is that the plaster will be like a sponge for the first and possible second coat. If you paint straight onto fresh plaster the moisture will be drawn out of the paint too quickly and it wont bond to the surface. It may look ok but it will probably start to flake off after a few months.

Some plasterers recommend PVA but that's because they don't have to deal with the after effects. PVA will become glue again when it get wet so when ever you paint the wall you'll have liquid PVA mixing in with it. You may also get the PVA bubbling as moisture gets through the surface. In short don't use it. It's the most over-used product in the building trade.

This happened to me when I repainted the spare room - the paint which was already on on of the walls bubbled up after I applied the new coat. I ended up having to scrape the wall back to bare plaster and start from scratch. I though that perhaps the paint I first used had been cack and that caused it but it makes more sense now. The previous person to paint the wall must have PVA'd it. Live and learn etc.