Chimney flashing question


In the continuing saga of the roofing company who doesn’t seem to pay too much attention to details, here is the best photo I can get of the flashing job they did on the chimney. (I won’t walk on a second story roof, so I can’t get a better photo).

The general manager told me they use “coil stock” to do the flashing. I suggested to him that the top edge of the counter flashing should, at the very least, have some type of stiffener bend to it to give it strength, but he said this is how they do it. To me, this flashing is only as strong as the caulk joint at the top. Once the caulk fails, and it will, the flashing is rendered useless and leaking begins, no?

Also, I note there is no “apron” or similar flashing on the downside of the roof, either.

I’d like comments from roofing experts about what they can see from this photo. As always, I appreciate any comments or suggestions.


Everyone does it a little different.
Looks good.
I cant see what he did behind and under the counterflashing so i cant judge.


When doing the chimney flashing with coil stock we still grind into the
chimney and have the coil stock return into the chimney. We also don’t use
caulking for this joint we remortar the chimney. Caulking should only be
used on the laps of the metal and hidden. Its hard to tell in the picture
if they did or did not do this. However, from the picture the metal does
look to be pretty straight which generally comes from the 90 degree into
the chimney and hem bend at the bottom. I have seen too many times a flat
stock anchored right over the chimney without returning in and at that
point yes it is only depending on the caulking and will fail.
For the apron portion I believe your referring to the counter flashing.
when using the coil you do not want to do it in one piece because of the
movement of the chimney. so you would run your count flashing up and then
the skirt right over top of it. which looks like it was done by the
Coild isnt a wrong way to do it and some states will only let you use
metal to flash chimneys such as NY. 99 percent of the time we use lead to
flash our chimneys when doing shingles. We do our chimneys this way when we
do our metals roofs.
With that being said from the picture presented I can’t tell if the
metal does return into the chimney and i can’t imagine any roofer even a
lesser quality one not putting a flashing going up the chimney. Hope this


Hard to tell from the pictures of it is installed properly. If the top of the coil is bent out and filled with caulk opposed to being cut into the masonry it will fail. What we do is cut a 1.5-2" reglet into chimney then put a back bend on top of counter flashing to mechanically attach to cut. I never use light gague aluminum (coil stock) against masonry chimneys. We always use copper flashing against masonry to prevent electrolysis. If aluminum is Used for step/counter flashing a buffer layor of ice shield or felt needs to be installed between the masonry and the metal. If using aluminum I recommend a minimum of .032 opposed to coil. As so the apron/base flashing I can’t see from the pictures of it is threw it is perfectly acceptable to put that under the final show course of shingles and then use flashing sent and nails so seal the last shingle and keep it in place.


Thanks to all. The metal is NOT cut into the chimney. There’s no stiffener
at the top and the caulk simply overlaps from the counter flashing into the
brick to hold it in place.


I’ve seen alot worse. I get to reflash alot of chimneys on 5-10 year old roofs because the metal is not ground in. I’ve torn off plenty of old chimneys just sealed in with caulk also that have held up fine. We grind in the metal and caulk it into place just fine.

It would be hard to go after the roofer on this one. “How do you flash your chimneys exactly?” Should have been asked before hand.


That appears to be a poor job and won’t likely survive over time.


Thanks for weighing in. Can you offer me a couple of bullet points that I can take back to the GM of the roofing company?


First thing is that the base & counter flashing need to be separated as in the base flashing is what goes around the chimney and is nailed into the roof and the counter flashing is secured to the chimney.

You may have what is known as a “gum lip” counter flashing but it doesn’t look it has an actual gum lip bend in it.

Your chimney is ideal for cutting a raggle (a slot in the chimney) and inserting the counter flashing into that, this wasn’t done.

It just isn’t a very good way to do a chimney and won’t last the life of the roof.


Thanks again Axiom.

There is no gum lip, or even a stiffener bend, in that counter flashing. It’s coil stock laid against the brick with a heavy, wide caulk bead over the seam and onto the brick.


I think Axiom covered it nicely and you can trust his input. Were I going to let someone else roof my house, he would be a top choice.


While it is far from perfect, it is still on par with probably 75% of other roofers (in my area) would have done. Imo it may hold up for the life of the roof, it may not (I’ve seen the odd chimneys that don’t even have counter flashing never leak inside).

How did your son find this roofing company and what made you choose to go with them? If they were on the cheaper side I think you got what you paid for with a lot of these issues (although the original rubber section of the porch I would have still deemed unacceptable).


The company is a large, highly reviewed and respected company in Toledo, Ohio. Owens Corning Platinum Installer, great Angie’s List reviews, etc. The GM who came out to look the place over and do the bid was personable, friendly, and nice. We did get one other bid that was about $1,000 higher from a major competitor.

The original EPDM was replaced by them, and the second install is far superior to the first, but virtually none of the manufacturers standards for install were followed. I am having another roofing company come out and bid to replace this second install. We still have not paid a cent for the first install, and my intention is to deduct the price of the second company’s replacement of the EPDM from the first company’s payment.


It looks like I’m late to the party. Axiom pretty much said it all. Here is a link that explains and shows both head wall flashing and chimney flashing.

If you have any further questions the the link should provide you adequate answers.


Thanks Charles. I am familiar with the different types of flashing. However, after the fact, the roofing GM told me that they don’t normally install head wall flashing. In my case the wall is cedar shake shingles. He said they would have had to cut the shingles to get the flashing installed. He offered to caulk the place where the wall meets the shingles.

Ultimately, I suppose this is all my fault for not giving detailed specifications to the company about how to do their job. I just assumed that a large, well reviewed company would do the right stuff. I was wrong. And I feel stupid about it as I was the “front man” for my son and his family on finding a contractor. At 61 years of age I thought I would have learned by now, but I guess not.


If this is an existing home there should already be headwall flashing installed and the roofers can re-use what is already there, simply using caulk is a poor solution.