# yellow stain on ceiling



## AlphaBeta (Sep 1, 2012)

Hi all, 
some yellow stains start to appear on the ceiling and not clear what would be the cause. I checked the roof/attic and nothing appear to be liking or dripping, although it is hard to get to all areas since the ceiling is cathedral vaulted. 

we bought the house about 10 months ago, it was freshly painted everywhere, and stains started to appear about a month ago. There is a sort of crack along the connection of the drywall, and the stain is coming along that crack. some more appeared next to the edge of the roof window frame. 

picture attached. If needed a better picture can be done tomorrow with more light. 

What that could be? From where to start to fix it? 
thanks AB


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## joecaption (Nov 30, 2011)

Looks like a condensation issue.
When there's a catherdral ceiling you really need soffit vents, foam baffles, insulation then a vaper barrier, with a ridge vents on the peak of the roof.


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## AlphaBeta (Sep 1, 2012)

Thanks joecaption for reply. The house is build in '98 (not that old), and it is townhouse in a big complex. So everyone has the same ventilation, unless someone messed it up in this unit. I will check it one more time. 

I think we do have soffit vents, foam baffles, and for sure insulation. 
Do not think we have vaper barrier, and also not sure if there is a ridge vents on the peak of the roof.

Would be possible to check if this is due to condensation issue from the attic, like to find stains or not necessarily? 

thanks, AB


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## notmrjohn (Aug 20, 2012)

Definately moisture from attic, that's a text book example,alpha, more than likely condensation, could be anther source of moisture which is worth looking for. Roof leak?
"it was freshly painted everywhere" just before you bought it covering the stains which were probably already there and are just now bleeding thru. Hard to imagine anything occuring in last 10 months that didn't exist already, except a leak. If you are very lucky the moisture source problem no longer exists and you can seal and repaint. Don't count on it though. here's an artical I found a while back, its actually about better way to insulate cathedral ceiling at beginning, but will explain what is going on in your ceiling and what to look for up there. http://www.applegateinsulation.com/Product-Info/Technical-Pages/249234.aspx The traditional way of trying to control moisture is to move lots of air thru there. Joe is trying to improve air flow. Turns out that may be exact opposite of how to do it. Not that joe is wrong, if that's how yours was built, that's about all you can do. This "new" method, dating back to '70's, prevents air movement. 
If a vapor barrier was installed it will be between the ceiling and the joists, under insulation. ( Here's where it would be nice to know your location, turns out you're in Panama we got a whole other story) if you have no barrier, or it is damaged you could be lookin at a messy repair. If previous owner knew of problem, depending on contrat, warranty, local law you may have recourse to releif. look around for any source of moisture, ask neighbors if they have similar problems and....
i just glanced back at your question. "Roof window"? Do you mean a.... sky light? ...... Sky lights are notorious for leaks! Dollars to donuts, there's your source of moisture. I gotta start reading the questions.


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## joecaption (Nov 30, 2011)

Post a picture of the roof standing out in the yard.
It's not the sky light leaking because the stains are above it as well as on the side of it.
Odd that it's only showing up along the drywall seams.
Is this just painted or is there any texture to the ceiling?


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## AlphaBeta (Sep 1, 2012)

thanks guys for reply! Very helpful. 

1) most visible is along the drywall connection, and there is a texture there now, that was not there before (10 months ago). Hopefully you can see on the picture. Also, at the far joint with the vertical ceiling it has a stain too, less visible, but also with texture sort of coming out. 
2) it is at the top of the skylight, so not a leaking from it as Joe mentioned. 
3) I checked one more time the attic, although hard to get everywhere there. There are no sign of leaking of the roof. However, one thing which I noticed, and actually mentioned by the inspector of the house too - the ceiling lights were probably installed after the insulation was done because the insulation around the lighting cans is open, thrown around, some cardboard/drywalls of the ceiling are wide exposed. Actually the crack where the stains is most visible is exposed from attic with no insulation. I did not see any moisture or stains of it in the attic. The insulation is 12" thick, i guess. 
4) we are in Illinois not Panama  BTW, what season is most likely to create this moisture problem: heating, AC or raining etc? 
5) a photo of the outside of the house is also attached, so you can see how the ventilation is done. Inside they did put foam baffles. 
6) I talked to the neighbors, and nobody has such problems, but they do not have ceiling lighting cans neither. 

Thus, i think you are right, this is a moisture problem. I plan to hire a contractor who will put back the insulation properly, cover the lighting fixtures with IR cans, check if the ventilation is done properly and if needs some improvements. Any other suggestions?


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## joecaption (Nov 30, 2011)

If there's an attic above these stains there should have been IC (in contact), air tite cans.
Remove a bulb and the trim ring it should say inside the can what it is.
In contact means they can be in contact with insulation.


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## AlphaBeta (Sep 1, 2012)

Joe, nothing is written inside the cans, and I also looked at the cans from the attic, and nothing like IC is written on them.


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## notmrjohn (Aug 20, 2012)

I din't think you sounded Panamanian. Climate tells you which side of wall to put vapor barrier. it goes on warm side. In most of US thats inside so it goes behind dry wall. In tropics and US South its outside so barrier goes under siding. Condensation occurs where warm air meets cold surface
joe,I'm not saying water is leaking at sky light and then on down. it doesn't have to be a big leak either. It doesn't happen fast. You might not see signs of leak or feelmoisture in air. I'm saying sky light could be the source of excess moisture in the attic, which then condenses. And I agree this is condensation issue. In summer there is warm moist air up there, it condenses on any cooler surface, uninsulated ceiling dry wall, ("where the stain is most visible") joist tops, light cans, sides of sky light even its top side and even fibers in insulation. Condensation occurs if cooler air leaking around cans meets moist air.Condensation on hard surfaces starts trickling down immediatly. in insulation it trickles slowly down over years. it should be stopped by vapor barrier but if not one, or pierced by drywall screws, light cans, sky lights etc. it can collect at those places ot trickle into seams between dry wall untill it comes out bottom. making those straight line stains.
In winter cool air is up there. Warm air rises thrugh ceiling, vapor should stop at barrier, if not, it condenses on cold surfaces. Then trickles down as before. Cool air doesn't hold as much vapor but if any excess moisture up there warm air grabs it. Then it condenses when it contacts a cold surface.
Non IC cans usually have holes in the sides that actually let cool or warm air pass through and meet its opposite. IC cans prevent insulation over them from causing heat build up in can ( I think I saw somewhere, it can get up to500 degrees in the can?) A lot of the after market covers which hold insulation away from cans still allow air leaks, they are primarily to keep insulation off can.

Alpha, you probably get more condensation in winter when warm moist air comes into contact with colder air up there. That doesn't mean that is when you will see effects down below, it may take time to trickle down. You* may* have a moisture source at the sky lite, I'm just sayin they're notorious for leaking. I'd sure like to see more soffet venting and a ridge vent. I don't know why folks are so skimpy with vents, they're no harder to put up and not much more, if at all, as expensive than solid panel. How is venting in rest of house? your place seems to be exactly like neighbor's. Except you have condensation problem, neighbors don't; you have recessed lighing cans, neighbors don't. Be sure to point that out to contractor. If he starts talking about power fans or vents its time for you to do more research. Opinions vary on those.


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## AlphaBeta (Sep 1, 2012)

Thanks John for detailed answer!


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