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Sidewall flashing w/o removing shingles

catch32's picture

Stupid homeowner question #78:

My roof is being redone. Complete tearoff after 120 years. I have a dormer w/ cedar shingle siding (see photo). In my discussions with the roofer we agreed he would remove the lower courses of shingle to flash where the roof meets the sidewalls.

I got home tonight and the roof was shingled, yet no sidewall shingles have been removed. It was dark when I got home so I can see what they did. Is it possible to CORRECTLY flash the sidewall without removing some shingle courses?

Of course I will call the roofer tomorrow and have a discussion. I was under the impression the correct way to flash was to remove the siding and to install the flashing. Is it correct to just slide the flashing under the cedar shingles? Just want trying to get an idea what is the industry standard way to do it.


(post #69114, reply #1 of 8)

Was there  step flashing under the old roof? If there was it is very possible to reuse the old. Have any pics of the new roof?

(post #69114, reply #2 of 8)

Two possibilities that I can think of (just had to do (2) with a slate dormer)

          1) the flashings were ok and he just shingled into them and they matched the current exposure

           2)he fed the flashings up from the bottom as the old ones were nailed to the roof by the upper corner and he fitted the new ones the same way.Very labourious and not as good as nailing to the sidewall

Edited 11/22/2005 9:12 pm ET by jako17

(post #69114, reply #3 of 8)


I redid the ledge on the bottom of the front gable. It looked the original flashing and it was gone (see photo). Roofer helped me replace it by removing the bottom 3 shingle courses and putting in new aluminum flashing with ice & water to seal the top of the flashing.

House had the original 120 year old cedar shakes under several layers of asphalt shingles. I was not home to see it, but my wife told me the skip sheathing on both sides of the dormer was heavily water damaged. The house had aluminum siding installed in the 80's. When we pulled it off there was a look of black caulk on the roof along the dormer sides.

Bottom line is likely it was the orignal flashing. In this situation would not removing the sidewall shingles be a better approach. The shingles are peeling heavily and will have to be replaced anyways.

(post #69114, reply #4 of 8)

The best thing to do is always remove a course or two of siding and replace the flashing. It's opening a can of worms, though, and scares some guys. It is difficult to remove siding without damaging the felt underneath, and when you do get some siding off you often find that the felt was already in poor condition and then you have to start asking yourself if the walls need to be redone.

On your house there probably isn't felt (is there?) so I suppose the roofer could have justified just jamming some flashing in there, either from the bottom or from the lower end. When there's felt you always have to be sure to get behind it.

(post #69114, reply #8 of 8)

The roofer should have been made aware that you are going to redo the siding on the dormer by your GC and removed the shingles as needed to put in new flashings when doing the roof .That will give you a good seal .I would suggest a strip of ice and water shield under the flashings.Secondly re- the ceder shakes ;look into a breathable underlay and if staining them, prestaining the backs before application to balance the moisture intake with it's associated cupping.I have found in my limited experience that home owners will quite often do that for me if I drop off the shakes and stain a week or so before commencing.

(post #69114, reply #5 of 8)

Roofers always use the existing step flashing if it's in good shape. What if you had clapboard, vinyl siding or stucco on there. They're not going to take that off. The problem with this is, is that the roofer told you he was going to take it off, therefore he becomes a sider to install the sidewall shingles back and he didn't do what he said.

Do you have a contract with him where he says that he will remove the siding and old step flashing and install new step flashing and siding?

Joe Carola
Joe Carola

(post #69114, reply #6 of 8)


Reroofing is part or a large renovation and addition project. Roofer is a sub of my GC. No direct contract with me.

Siding is in poor condition on dormer and will be replaced anyways, so flashing can be redone then. Assuming all the shingles come off what is the best way to seal the flashing? Ice & Water shield over top of flashing?

(post #69114, reply #7 of 8)

If the old flashings were only nailed to the roof, he might have been able to pull them out and fish new back in. That's doubtful. He may have re-used the old, but if siding is 120 yrs old as the house is, I wouldn't accept that, since the experation date on the flashing is about here. If redoing the siding is imminent, new flashing can be installed with the siding, so NBD.

He also could have left the old flashing in place and slipped in new over the top of it. I've done this numerous times to keep from disturbing the siding.

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