Watersealing a dormer

Old 10-16-07, 12:02 PM
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Watersealing a dormer

I have two dormers on my cape cod home that are leaking, one more than the other. The roof is about 5 to 8 years old and was installed by the previous home owner, not a company. I do not think they did a proper job waterproofing around the dormers and protecting it from the elements. I doubt that any type of ice and water guard was used and at best hopeful that they used flashing but not sure. There is a large amount of black caulk along the roof line where the dormer siding meets the shingles. There is a J-channel present as well. The leaks appear to be coming from the top of the dormer where the top roof meets the house roof. My question is how do I install the ice and water sheild properly and get the flashin installed? Can I reuse the vinyl siding that is on it now if I remove it without damage? I was looking on the net but found little information. Thanks
Old 10-16-07, 02:52 PM
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Welcome to the DIY forums!

It's difficult to give you step by step instructions on something so complicated, but I'll offer a few thoughts.

You are right that the gobs of blackjack sealant are a bad sign. It makes me wonder if you have 2 layers of shingles on the roof, or just one?

Its hard to tell from your description where the leak is coming from. Do you suspect the valley where the dormer and house roofs intersect? Or are you thinking the leak is coming from where the shingles go under your vinyl siding?

Vinyl siding can easily be removed, then reinstalled, provided you number the pieces carefully. One trick I sometimes use is to unhook the pieces from the nails, leaving the nails in place so that you are sure everything goes right back where it was. Numbering the back of the siding with a marker helps you keep track of what pieces went where.

If you have digital pictures that might more clearly show the areas affected by the leak, it might help us get a better understanding, and might enable you to more clearly picture the replies. Pictures can be directly inserted by using one of the photo icons that you will see as you reply... or you can just paste a link to the location of your pictures online provided you have uploaded them to a file sharing website somewhere.

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