Home>Discussions>EXTERIORS>Dormer leak due to lack of step flashing + "quick fix" needed for storm
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Mr. Bananas
Dormer leak due to lack of step flashing + "quick fix" needed for storm

I live in North NJ and we had a rainstorm the other day and I heard water dripping onto a vent. I went into the attic and saw that I had a hole in my attic roof about the size of a pen (diameter) - see the third picture; it is where the red wire is coming out of the dormer beneath the J channel. I didn't see this hole because the previous owner had insulation over it, which was absorbing the water. The leak is quite significant. It is located where dormer wall meets the roof.

I did some research and I found out that I'm in need of step flashing. Actually, I'm in need of a new roof but I'm trying to wait until this coming spring for financial reasons.

I ripped off some of the roof shingles and I noticed that along the dormer wall, the previous owner had put many layers of shingles (instead of step flashing) most likely to divert water away from the dormer. Also, the J channel is preventing me from accessing the shingles along the wall so I am unable to easily insert flashing from beneath.

My questions: What can I do to plug this leak to get me through this winter? I bought Karnak 19 Ultra Semi and my plan is to put Karnak all along the dormer wall. Will this get me through winter? Anything else you would recommend?

https://www.youtube.com/watch?v=DOneZN1W0gw

Mr. Bananas
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm
A. Spruce
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm

I'm seeing multiple issues there that can only be repaired by stripping the roof completely off and possibly some siding. If you're trying to button up for an impending storm, then I would patch the shingles back in as best you can, then gob the area with roofing tar, like was done during a previous repair or at time the roof was originally installed.

Issues I see:
1 - No roofing felt.
2 - No step flashing or transition flashing.
3 - Multiple layers of old, disintegrating shingles.
4 - Uneven roof deck creates pockets where shingles are unsupported and will unknowingly break when walked on during gutter cleanings or roof inspections, or other roof related work.

I'm certain that more issues will be found as the roof is removed and that area of the leak is opened up. probably some dryrot, possibly some pest issues.

Mr. Bananas
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm
A. Spruce wrote:

I'm seeing multiple issues there that can only be repaired by stripping the roof completely off and possibly some siding. If you're trying to button up for an impending storm, then I would patch the shingles back in as best you can, then gob the area with roofing tar, like was done during a previous repair or at time the roof was originally installed.

Issues I see:
1 - No roofing felt.
2 - No step flashing or transition flashing.
3 - Multiple layers of old, disintegrating shingles.
4 - Uneven roof deck creates pockets where shingles are unsupported and will unknowingly break when walked on during gutter cleanings or roof inspections, or other roof related work.

I'm certain that more issues will be found as the roof is removed and that area of the leak is opened up. probably some dryrot, possibly some pest issues.

I'm surprised you were able to tell there were multiple layers of shingles. I think the previous owner either put new shingles on top of old ones or put more shingles along the dormer wall instead of flashing.

On the same day as my first post, I went up and put Karnack Ultra and it seemed to do the job. However, we had another thunderstorm this past Wednesday and a new leak appeared further up the dormer wall. We have more rain coming tomorrow so I applied Karnack to that area as well. Hopefully it'll last until spring.

I know I need a new roof but for financial reasons I'm waiting until next spring. In addition to flashing and felt paper I will also be adding an ice shield. Is there anything else I can do as well?

Thank you

A. Spruce
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm

Where I am located, ice shield is not a requirement, so I can't speak to that sort of thing.

What you typically are looking for in a reroof is to strip to bare deck, From here any rot or damaged areas can be assessed and repaired, then new felt (preferably 30# ), flashings, and shingles. Excessively wet or cold areas require ice/water shield, dryer regions do not.

If there is no step flashing, then it should be installed, which may require the removal of siding to do so. If you've got a chimney, it needs proper flashings as well. If there is no transition flashing between a slope and a face, you'll need that too. What's the difference? Step flashing is applied along the rake or diagonal of the roof and a vertical surface, transition flashing is between a horizontal face and where it meets a roof line.

Mastercarpentry
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm

Any idiot can learn to lay shingles and make a roof look good, and that's at the skill limit for many (if not most) roofers. Really good roofers do flashing correctly instead of applying sealer and hoping it holds. That takes time and that costs money but in the end is worth it. Between now and spring you should educate yourself on how the flashing your house needs is supposed to be done, then put those details into the contract with your roofer and watch to see they are indeed done correctly. If you're not specific they may do something else claiming that to be 'standard' and correct.

It's the flashing which makes the difference between a good roof and a crappy one.

Phil

RobmanQ
Re: Dormer leak due to lack of step flashing + "quick fix" needed for storm

As stated above, proper flashing is most important of any good roofing job. Unfortunately, a lot of roofers just do not get it, and that is because flashing should be coordinated with the builder, who usually at this time is in the showroom buying a new pickup or with his lawyer divorcing his wife. For the winter, just install and fix the exposed portion with roofing as much as possible. Consider ripping out the bogus channel which was probably installed during the last roofing job since it does not look original. Install temporary L flashing under the siding and over your roofing, that should keep out majority of the water for now. Cover the dormer wall / roof transition with plastic if you have to, just to get you through the winter, and screw it down with battens, use tuct tape on the wall. In the spring, rip off the old roofing and get a new roof. Make sure all transitions are properly flashed. You may have to cut back the siding a bit to install step flashing, and counter flashing. The siding should maintain a minimum 1 1/2" gap above the roofing (this varies with different parts of the country....check with the building dept.) There should be counter flashing installed over the step flashing once you are finished. Good luck.

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