DIY Message Boards
Skylight leaking or condensation?

This topic can be found at:
http://boards.diynetwork.com/eve/forums/a/tpc/f/9221916776/m/9263992577

Nov 17, 2013, 10:59 AM
DanteBK
Skylight leaking or condensation?
Here in Los Angeles we just went from 88 degrees and sunny to 70 degrees and misty over the period of a single day, and shortly after this happened, I noticed a ring of mysterious stains around the skylight in my condo.

It's like a series of little dots completely encircling the skylight area. I think it's from drops of water running down from the little shelf around the skylight carrying dirt/dust with it. But is this water from a leak or is it from condensation because of the weather change? It seems strange there would be a leak around every corner of the skylight at once, but the condo association did have a lot of roofing done on the building over the summer, and perhaps they damaged the seal around the skylight?

Any suggestions on how I could diagnose this issue? I don't own a ladder tall enough to get up into the skylight (it's at least two feet higher than the ceiling around it) and am not sure if I'm allowed on the roof (though that can probably be arranged).

Photo attached.

Thanks in advance!
Dante


Nov 17, 2013, 12:46 PM
GardenSprite
Can't answer your questions but just wanted to observe how curious it is to me that the spots appear to be evenly located and round. The two sets on the far right look as if they're actually evenly spaced.

I've seen skylight moisture leaks (in an outdoors shed) but they were more random and ragged.

I'd be interested to see what the others here think about this.
Nov 17, 2013, 01:22 PM
redoverfarm
Could it be the drywall fastners ( nails or screws) since it is close to the edge.

This message has been edited. Last edited by: redoverfarm,
Nov 17, 2013, 04:55 PM
Jaybee
The even spaced holes are because there is a corner bead embedded in the drywall to cover the skylight well to ceiling corner. You are getting moisture behind the drywall and the water is running down to the bottom. Then, it continues downhill, following the inside of the corner bead as a track - but since the corner bead has regular spaced holes the water is finding it's way through there.

That explains the spots, but not the leak. Depending on how the upper edge of the drywall in the well is set up, you could be getting condensation that runs down off the skylight and behind the drywall. Hard to tell from the pic, but it appears that the drywall just runs up close to the glass of the skylight.

It's also possible that there is a flashing leak alongside the skylight - water gets in there and migrates downhill along the edge of the skylight well.


Jaybee
Nov 17, 2013, 05:30 PM
DanteBK
I'm not sure if the spots are coming from behind the drywall, as they can be easily wiped away with my finger. Some of them have clear trails coming down from the skylight (photo below), though most do not. But this is not a subject I know well, so perhaps they could be coming from inside the drywall and still be easily cleaned off?

As far as I can tell, the upper edge of the drywall is not touching anything. The skylight looks like it's attached an inch or so away from the edge.


Nov 17, 2013, 06:29 PM
Sparky617
If you were in a colder climate I'd swear it is condensation on the glass from bathing or cooking. Given your mild LA location I can't imagine you're hitting the dew point at 70 degrees overnight. Is this skylight in your bathroom or kitchen? If either, do you run your exhaust fan when bathing or cooking?

I'd bet on condensation over a leak, but hard to say from the picture. With your second picture it definitely looks like it is running down the drywall and collecting at various points along the edge. The dots may or may not line up with holes in the corner bead as mentioned by Jay or were nails/screws are as mentioned by Red.

If it is in your kitchen or bathroom I'd wipe everything clean and use the exhaust fan and see if the condensation on the glass is minimized going forward.


General Disclaimer

Any advice given here is general in nature and is not necessarily valid for your given area. If in doubt check with your local codes enforcement department for what is required when doing electrical, plumbing or structural work on your house. Permits may or may not be required in your area and home owners may not be able to DIY some tasks. I have no way of knowing if you have the skills needed to complete the tasks you are asking about, when in doubt seek professional assistance.

My advice may be worth exactly what you pay me for it. :-) For the record I did not stay in a Holiday Inn Express last night.
Nov 17, 2013, 06:47 PM
Jaybee
Is the glass curved or straight?

If curved, then condensation will run towards either side. From there, it could easily get on or behind the drywall.

Your second pic clearly shows water running down the face of the drywall and collecting on the underside edge.


Jaybee
Nov 17, 2013, 07:19 PM
DanteBK
quote:
Originally posted by Sparky617:
If you were in a colder climate I'd swear it is condensation on the glass from bathing or cooking. Given your mild LA location I can't imagine you're hitting the dew point at 70 degrees overnight.


Sorry, I wasn't clear, 70 degrees was the high. It got to 45 or so overnight. Yes we have big temperature swings here. 88 high one day then 45 low 36 hours later.

It's not near the kitchen or a bathroom, but it's only a few feet from the laundry room (which is behind a slatted door).

quote:
Originally posted by Jaybee:
Is the glass curved or straight?

If curved, then condensation will run towards either side. From there, it could easily get on or behind the drywall.


It's curved, like a little dome.
Nov 17, 2013, 07:58 PM
Sparky617
Is your dryer vented outdoors? Are you sure it is? Make sure the vent is working freely and hasn't become dislodged from the back of the dryer.

Given the colder temperature the skylight could be hitting the dew point if the humidity level in your condo is high.


General Disclaimer

Any advice given here is general in nature and is not necessarily valid for your given area. If in doubt check with your local codes enforcement department for what is required when doing electrical, plumbing or structural work on your house. Permits may or may not be required in your area and home owners may not be able to DIY some tasks. I have no way of knowing if you have the skills needed to complete the tasks you are asking about, when in doubt seek professional assistance.

My advice may be worth exactly what you pay me for it. :-) For the record I did not stay in a Holiday Inn Express last night.
Dec 07, 2013, 09:53 AM
DanteBK
It must have been condensation, because it's rained here more steadily a couple times since this happened and there was no additional "leaking". I cleaned the area around the skylight and all is well.

Thanks for the feedback, everybody!
Dec 07, 2013, 10:27 AM
GardenSprite
Glad things turned out well for you and thanks for the report back on what's worked in this situation.