Any tips on weatherizing an already installed skylight, that is leaking on a shingled(3-tab asphalt) roof. What is the BEST sealant to use? Is flashing or the sealant usually the common cause of skylight leaks? Any insight, or people with experience in this realm is greatly appreciated.
thank you!!!! chipper email: [email protected]
10-25-2003
Built from locally sawn hemlock, this functional outdoor feature uses structural screws and metal connectors for fast, sturdy construction.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
Where do you suspect the leak is...
Dome, curb or flange?
What kind is it...
Who ever invented work didn't know how to fish....
If a skylight is leaking, does that mean that it is letting darkness in?
Or maybe sky?
Vast projects should not be founded on half vast ideas.
ROAR!!!
We'll never know...
Chipper never opened up a dialog or answered any questions...
Maybe the light in the sky is leaking out and a new black hole is forming...
NEXT!
Who ever invented work didn't know how to fish....
done properly there should be no areas where the installation relies on caulking to remain watertight. I'd be looking at the flashing installation. I always make my own steps, couterflashings and curb flashings.
I'm with SledBC. There is very little need for sealants on a skylight installation. The flashing does the trick with no problem as long as it is applied correctly.
What's the pitch of the roof? With 3-tab shingles, it's better if the pitch is about 4 in 12 or steeper.
I do use plenty of Ice & Water barrier, though. I extend it about 18" in all directions around the skylight and lap it up on the curb before weaving the shingles and flashing.
If the leack is really at the curb/sheathing joint, there's no quick fix. Peel back the roofing and do it right. It should only take a few hours.
Al Mollitor, Sharon MA
chipper,
How long has this skylight been in place?
It may be that it isn't the installation that's the culprit at all.
Had to make repairs three years ago to a unit that leaked along the sky-side lower edge of the glass. The manufacturer's caulking/sealant had become so dried and brittle that it looked like rock candy and leaked like a sieve. The window had only been in six years, but the warranty period was up. HO choice was repair in place if at all possible. Said I'd try, but no promises.
I scraped and vacuumed out what I could of the old sealant on the sky-side of things, then cleaned the area well with lacquer thinner. Carefully applied/forced a bead of high quality polyurethane caulk as the replacement. It hasn't leaked since.
remove the shingles around the lite and install new step flashing.
If you refuse to do so, than try using Karnak flashing cement under and over some tar impregnated fiberglass tape onto the sides and top of the lite and onto the roof but thats not really the right way,although it has worked in the past.
Be a lazy mans way out
andy
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
Chipper
Proper flashing technique on a skylight in a shingled roof shingled roof will eliminate the need for any caulk,sealant,gook,etc. I've installed probably a hundred or so Velux skylights over the years and never had a leak. They have a great flashing system that's simple to install and complements they're units nicely.Ice and water shield is probably a good idea but it's been at least eight years since I've put in a skylight and it wasn't as readily used in the years previous to that. We didn't find it necessary however to get leak free installations.
My thought would be to try to find out where the leak is first. No sense trying to solve a problem when you don't know what/where it is.
I also agree that caulk isn't the answer - It's just a temporary treatment for the symptopms of the problem.
I know what Victoria's Secret is. The secret is that nobody older than 30 can fit into their stuff.
My best sugestion if it's not Velux don't waste your time , just change it out. 19 years in on the job and the only problem was a seal failur around the glass.