Yellow marks on freshly painted plaster

paintpot

I am refurbishing a cottage built around 1860. I stripped the lounge ceiling of three layers of wall paper and have had the entire lounge skimmed, ceiling and walls. The problem is, having painted the ceiling loads of yellow discolouration marks have come through the white paint. The plasterers are baffled as they applied two coats of PVA before the plaster and it hasn't happened anywhere else in the property. I believe the ceiling before had lime plaster on and the plasterers were a little concerned as to how the new plaster would take, they said it could bubble and fall off but I took the risk and it was fine. I am familiar with how to paint new plaster having done it before, there are no leaks coming through onto the lounge ceiling, there was no discolouration before the wallpaper was stripped and I have applied stain stop to the stains which normally works for water stains but the marks just keep coming back. Any suggestions as to what is causing these marks and what can be applied to stop them coming through the paint.

thanks

PROFESSIONAL_LANDLORD

Any suggestions as to what is causing these marks

Had similar experience years ago, water ingress from a chimney

and what can be applied to stop them coming through the paint.

Gloss paint ! once dry re-paint

paintpot

Thank you, I've been waiting days to read your reply as the site was down.:mad:

misgrace

I wouldnt use gloss paint, its too shiny, and you need a key for your emulsion to adhere to.

As you have already painted the ceiling, at least the ceiling is sealed, so I would advise you to use oilbased undercoat, this has a matt finish, and then your emulsion will adhere to it no problem.

Get some cheapo oilbased undercoat, thin down with white spirt, and stir well, then roll that on the ceiling, make sure every part of the ceiling is covered.

Leave till next day, give the ceiling a light rub down, and then apply your emulsion, I wouls slightly thin down your emulsion, you dont want it too thick going over your undercoat.
You will probably have to do 2 coats of emulsion, but you will be stain free.

Make sure the UC is oilbased, and you wont have any stains bleeding through.:D

paintpot

Thankyou misgrace, sounds like a plan :T

misgrace

Your welcome paintpot

Let me know how it pans out, if the stain is going to come through (which it wont) it would normally come through within 24- 48 hours.

But, dont miss an inch with your undercoat, as sure as dammit thats the bit the stain will bleed through.:rolleyes:

paintpot

Will do!


Don't you just love old houses! Random pipes appearing in random places, dodgey ceilings, the list is endless!