Flashing a dormer. Need help from a pro. (Updated with pics)

I extended a piece of flashing on the side of a dormer. They didn’t use step flashing or turnback flashing. They used angle flashing and it looks like they sealed it with roofing cement. I just tucked the extension piece of flashing under the old flashing about 4 inches.

Do I need to seal under the shingles with roofing cement?

I wasn’t sure if I needed to or not. The bottom portion of the angle flashing is around 6 inches so water would have to travel that far horizontally to get past the flashing.

The problem area was the the bottom side of the dormer. They just cut the top portion of the flashing and nailed it to the stud. I am having a sheet metal shop fabricate me a corner flashing. How to professionals seal the ends. Keep in mind the end of the dormer is the siding of the house that goes all the way to the ground.

Any help would be appreciated.

pictures would give us a better idea,it doesn`t sound right

fronty, it’s kinda hard to explain without pictures. But using a continous piece of flashing to flash a sidewall is not the correct proceedure. It should be step flashed instead.

See link for an example of step flashing for a chimney, same principal applies to sidewalls.

restoremyhome.com/images/syk … %20008.jpg

Keep in mind this flashing is in progress and is not complete, but it had to be corrected from the picture below,which I believe is what you talking about.

restoremyhome.com/images/syk … %20003.jpg

and if anything use silicone at corners where stepflashing changes direction

I should have brought my camera. Well, it does look like the second picture. I can’t really replace the flashing because I’m not replacing the roof at this time. I would have to rip off all the old shingles where the flashing meets and take the siding off of the dormer. I’m guessing step flashing is used because it gets weaved into the shingles. A continuous piece of angle flashing just lays below the shingles. If I seal it with roofing cement, I should be ok right??? No damage has occured down the side of the dormer. The only damage is at the end of the house. I’ll take pics tomorrow. I’m going to do some work on it today.

Sealing with roof cement in my opinion will keep it from leaking on a temporary basis. You might have to continue to maintance it by going up every 2 years or so to clean out old dry and cracked cement and reseal with new.

If a penetration or wall flashing is correctly flashed there should be NO NEED for roof cement.

OHH Gawd ! on corners the best way is to use a piece of lead that way you can mold it around the corner and make it nice and tight. No caulking or tar needed.


they make a pre bent corner…called flash-rite. most supply stores carry them $2 a piece. problem fixed (as far as the corner goes)

I went to ABC Supply and they said that they don’t sell anything like that and that tradesmen just make them. Thanks for the info. Unfortunately, I already had a sheet metal shop fabricate one for me.

i think home depot and lowes both sell them

Copper + locked corner + solder = love

ditto rooferj

got regular 4x6 flashing in hundreds of homes.chimneys
walls, doormers, whatever.
problem free for 20+ yrs. if you do not know how to get shingles to seal to a peace of 4x6 then you may very well need to step flash.

ditto theroofinggod#1 , reply 5/30/07 4:25pm.


Thanks for the help.

It really isnt any rocket science. lead flashing you just mold it around the corner problem solved. Yes we also can do the locked and solderd corner on spec jobs. but lead is quick and works just as well. those lumberyard corner pieces are cheap crap.


Holy Christ ! ! Yes, I just saw the picture.


I looked all over those places and couldn’t find any.

Needs more tar…

Serious??? If so, where should I add the tar?

sorry time to call in a pro

What is wrong with it? What would a pro do? Maybe, he would use step flashing instead. Well, that is out of the question at the moment. I would have to rip all of the shingles out along side the dormer and remove all of the siding. Details please… Keep in mind that the angle flashing worked well for the last 20 plus years. It was the corners that were not protected well.