Delay after plastering

[JohnD]

Next week, I am having some walls and ceilings replastered in an old house. The old plaster has been hacked off and the walls are dry.

How long after replastering can lining paper and emulsion be applied?

 

[dcdec]

Drying time generally depends on the ambient temperature. The best way to tell is you'll see the dry plaster turn a light salmon colour and when the wall is uniformally this colour its dry and ready to paint, could be a couple of days could be a week.
Your post does beg one question tho, why do you want to line newly plastered walls?
Quick tip, if your going to paper dont mist coat with emulsion as in years to come when the paper is stripped it will pull the emulsion off creating a heavily pitted surface. Use a paste size or for best results for the future seal the plaster with zinsser guardz, its around £25 a gallon but will leave an excellent paintable surface, seal the walls and make the paper easier to strip. I know your probably not too worried about ten years time but its a really nice professional approach for future applications or the next chap that comes along to do it.

Any paint applications water down by 40 % for mist coat and the non vinyl paint thing is a complete fallacy it only applies to plaster when the walls have been bonded. Fill after mist coat marking the filler with a bit of blue tape, rub down when dry, prime filler with watered down emulsion then pole sand the walls to de-nib and proceed with finishing coat/s

 

[JohnD]

the lining paper is because some sections of some walls have had plaster removed, others have not. The lining paper is to even up the finish as some of the old plaster is imperfect.

The work is being done by a local building firm as part of an insurance claim, following a burst pipe in December, and they have specified lining paper (the walls previously had various heavy patterned, or painted textured papers, but I prefer a simple matt pale painted finish now).

I had not heard about not papering onto emulsion, when DIYing, I usually tidy up the walls smooth, and emulsion, and had always thought this gave a nice surface to paper on in future.

 

[Richard C]

If your talking about a re-skim, 10-14 days will be OK for painting but if you’ve had a full base coat & skim, leave it 4 weeks before painting. Sticking paper over it is another matter & you will need to leave it longer. New property advice is to wait at least 6 months before papering as it will effectively seal in any residual moisture which can lead to all sorts of nasties & you may end up stripping it all off again. If old solid external walls are involved, I assume you’ve taken steps to prevent moisture ingress (which all solid external walls will suffer) & at least a waterproof render base coat is being used?

As a plasterer, I & most other spreads on here will disagree that not using vinyl emulsion for misting new plaster is “a complete myth” & thinning 40% is way too much; 25-30% is all you need, 2/3 coats in quick succession.

Why on earth would you want to stick lining paper over nice new plaster

Edit;
Sorry just read your new post

 

[dcdec]

Guess we'll have to disagree on this one Richard but i have never applied more than one mist coat and never water paint down less than 30- 40%.

Permeable paints only need to be used on surfaces that may not be completely dry and thats not just my opinion its stated in the NVQ P&D manual which honestly is the best reference book for the trade, it also makes no mention of multiple coats of primer. If you apply one coat of suitably thinned emulsion it does the job its meant to do which is satisfy the porousity of the plaster, subsequent coats are pointless.

 

[Richard C]

Permeable paints only need to be used on surfaces that may not be completely dry
and thats not just my opinion its stated in the NVQ P&D manual which honestly is the best reference book for the trade,

In a new build, you can wait at least 6 months or longer before the fabric is dry enough to accept non-permeable paint or paper; I would never risk it on new plaster. Sorry but I would hardly regard the NVQ P&D manual as a definitive reference source for building/plastering but I’m not in the pro dec trade so I probably don’t know my asre from my elbow.

it also makes no mention of multiple coats of primer. If you apply one coat of suitably thinned emulsion it does the job its meant to do which is satisfy the porousity of the plaster, subsequent coats are pointless.

An initial mist coat will be sucked dry by new plaster in no time, adding additional coats in quick succession keeps it moist & allows the plaster to “suck” the paint into the microscopic pores in the surface giving better adhesion. Thinning 40% may have a similar effect but I’ve never heard of anyone thinning mist coats that much. I’ve been criticised for advising 25-30%, many will tell you 10% is OK & some will say to use it neat. IMO, they are only interested in saving time & won’t be around in 5-10 years time when it either starts to crack & fall off or comes off with the wall paper someone else has stuck on there.

 

[JohnD]

I can't wait another month for them to finish, they'll have to get dehumidifiers in.

 

[misterhelpful]

I'll just chip in with my thoughts if that's ok?

I agree (dcdec), that more than one mist coat is not necessary, but also (Richard C), that if you put 2 coats on in quick succession, ie finish one wall then do it again before starting another, it does give you a better base for your topcoats.

I have never watered down a mist coat more than 20%, but usually use contract matt which is quite thin anyway. I have used vinyl without any major problems, but it has caused some lifting on occasions.

Also, I have papered and painted plaster skim as soon as it is dry without repurcussions, but always leave base coat and skim at least a month before doing either.

JohnD, I'm with dcdec about not mist coating plaster before papering, but if the rest of your walls are already painted, it makes little difference.