Help! New coat of white paint on ceiling now covered in brown marks?

[Katdcruz3]

Hi All,
Hoping someone can help me please - I'm so confused.
We are trying to redecorate our bedroom (have just moved in to this house). The bedroom was all white - white ceiling and walls. We sugar soaped, rinsed the sugar soap off. Left to dry overnight. Today we start painting the ceiling in another coat of white just to freshen it up, and it's turned brown and patchy - I believe these are water stains.

One thing I read suggested it may be a reaction from something in the paint with the existing moisture? But why were the previous owners able to paint it white?

Is the solution a stain sealant? If so any recommendations please?

Also to complicate it further, my hubby thinks the previous owners may have wall papered the ceiling (????) then painted over it. If this was the case, what solution would you recommend here please?

And would you use the sealant on the walls as well before painting just to make sure there is no issue?

We have checked the loft and there's no obvious leak to fix. And I should add this room has an en suite, so possible damp from there?

Thank you all kindly!

 

[blup]

Thin down some oil based emulsion, or just keep adding coats of wb paint and it should eventually go.

Blup

 

[JohnD]

did a previous occupant smoke? Or are these marks near a chimney?

if it's water, look at the upper surface of the ceiling by rolling back the insulation. Plasterboard is liable to have the paper peeling off, but you should see marks

post some photos of the marks.

p.s.
don't use glue.

 

[Katdcruz3]

Thanks for your replies. Here's some pictures of the marks - before painting this coat of white paint the ceiling was just normal white, no brown marks!

 

[Wayners]

May have had stain block on and over time it's degraded, so along you come and if failed.

I'd either use coverstain and give it 48h and paint white or you could use johnstones stainaway which is waterbased and hope that fixes. First coat will blead stains but they lock in and second coat will be fine.


Zinnser also make other stain blocking paints however I have not used myself. I tend to stick to what I know works as I can't be messing. As a diy person consider stainaway but don't back roll it or second coat too quickly, give the coats 12h to dry before coating again

 

[Katdcruz3]

Thanks for all your help on this - we used Zinsser cover stain (2 coats) and then 2 coats of Matt emulsion and looking good now! Phew such a relief.