My Skylight is Leaking!! (Tucson, Arizona)

The leak is coming from a lower corner:



The Glass and metal frame look fine:




And I put my hand on the inside corner while it was raining, and it was dry:



So I'm pretty sure the leak is from this crack in the Marine foam used to foam the roof:



And so I'm sure the proper way to fix this would be to remove all the old marine foam around this box (or whatever you call it), and re-apply new
foam. Obviously I can't really see how the box is attached to the roof,
because the foam covers everything.

But shouldn't I try to re-foam just this crack, and the few others that
are around the edge? It looks like the leak is from this one crack, but
I'll re-seal all of them.

Any advice for what sealant to look for at Home Depot? It has to be
polyurethan or silicon, right? Shouldn't I try to cut away some
of the old foam around the crack?

I live in Tucson, AZ.

Thanks for any and all advice.....

Water can travel a great distance before it shows up, I would use a hose to flood the flat part of the roof and make sure the leak isn't else about.And welcome to the site.

nealtw said:

Water can travel a great distance before it shows up, I would use a hose to flood the flat part of the roof and make sure the leak isn't else about.And welcome to the site.

Click to expand...

Ok, yes, that's a good idea I also read elsewhere, but wasn't sure
if I should try.

That would make it more certain which crack the water is flowing
through.

It would also be pretty easy to do myself, because the skylight
is now open, so I can visually see when it's dripping.....

Any advice for what sealant to look for at Home Depot? It has to be
polyurethan or silicon, right? Shouldn't I try to cut away some
of the old foam around the crack?

Paul, first off to House Repair Talk!

If it were my skylight, I'd gently remove all the loose caulk and roof cement that has been applied around the skylight curb. Then I would apply a coating of elastimeric coating to the roof deck and the side of the curb. Silicone is a good caulk, but not for what you are wanting to do. It sets up to hard and doesn't allow for thermal expansion. Roof cement is never to be used when it has direct exposure to UV rays. You can get the elastimeric coatings at a roofing supply house or a commercial contractor center. Make sure ALL the cracks have been sealed.

Also, make sure there is a good seal in between the metal frame and the plastic bubble. Water can get in where the frame sits over the bubble, if you can find some, apply some butyl tape in between the plastic and metal to seal it up. And it wouldn't be a bad idea to someday get a curb mount skylight top to replace that bubble, they are problematic for leaks.

oldognewtrick said:

Paul, first off to House Repair Talk!

If it were my skylight, I'd gently remove all the loose caulk and roof cement that has been applied around the skylight curb. Then I would apply a coating of elastimeric coating to the roof deck and the side of the curb. Silicone is a good caulk, but not for what you are wanting to do. It sets up to hard and doesn't allow for thermal expansion. Roof cement is never to be used when it has direct exposure to UV rays. You can get the elastimeric coatings at a roofing supply house or a commercial contractor center. Make sure ALL the cracks have been sealed.

Also, make sure there is a good seal in between the metal frame and the plastic bubble. Water can get in where the frame sits over the bubble, if you can find some, apply some butyl tape in between the plastic and metal to seal it up. And it wouldn't be a bad idea to someday get a curb mount skylight top to replace that bubble, they are problematic for leaks.

Click to expand...

Thanks for the welcome, and it's good to be here.

Ok, the box is called a "curb", gotcha.

Ok, I should be able to get this stuff at Home Depot:

http://www.homedepot.com/p/Gardner-...c-Roof-Coating-SK-7705/100317815#.UpMnuyfNkwg

That's the same elastomeric coating you are talking about, right? It's
also white, which will match the original marine foam used on my roof,
and although it doesn't mention it in the description, the user reviews
talk highly of it's ability to stop leaks, which is what I need.

What is a good method to prep the surface of the old foam, so the new
coating will stick to it well? I will certainly seal up ALL the holes as best
I can.

I can use this butyl putty tape between the glass and the metal frame,
right?

http://www.amazon.com/dp/B0070O93HA/?tag=skimlinks_replacement-20

And I'm quite sure my skylight is glass, not plastic.

Thanks for the great advice!

All the bubble top skylights I've seen are plastic. Make sure all your surfaces are clean and free of grease, oil and or contaminates. On the curb, use a cleaner like 409, WD-40 works wonders on getting roof cement off with a little elbow grease, use a scrapper and clean the mating surfaces on the skylight and frame. Any thing you use to clean, make a test area to see if the cleaner is compatible.

Henery makes a gallon bucket size that should be more than enough to coat the curbs.

Ok, so the guy at Lowe's has educated me that the
product i previously posted is not the correct stuff
to use to seal leaks. This is the stuff:

http://www.lowes.com/pd_139933-29-5227-1-20_0__?productId=3013306

Which should be used with a patching fabric:

http://constructionsupplycentral.co...pair/gardner-6-x-50-roof-patching-fabric.html

I will thoroughly clean the old foam coating, and I may even
cut out portions of the leaking area, and then I will apply the
first coat of the Black Jack roof patch over the holes and leaks.
Wait until it's a bit tacky, and then put the patching fabric on.
Wait until that sets a bit, and then add another layer of the roof
patch.

After about 24 hours, I can either leave it as is, or add another coat,
or add another coat of the previous product I had posted, which is
meant to be a top coat.

The butyl tape was not carried by either Lowe's or Home Depot, so
I'll get that online.....