Step flashing stucco chimney- what is going on here?

Waiting for the roofer to come back to complete the job. We just had a reroof with certainteed grand manor & copper valleys. after researching and finding that galvanized steel with copper can lead to corrosion, we asked them to replace step flashing with all copper to match counter flashing. They ran out of copper and have to come back again to complete the job. Is counter flashing supposed to extend out past chimney like this? What would be the way to address this situation?

Maybe someone has some proof,
Ive heard about dissimilar metals corroding each other but never actually seen it on a asphalt shingled roof away from salt water.
If its true, has anyone seen it here
where the corrosive action corroded faster and caused a problem faster than the shingles itself?

The copper is only for cosmetics.
Something to show off since it is so exposed outside the stucco.
I would have used painted galvanized steel
And matched to the evedrip color.
Why would they use this copper in the first place?
Because you asked for it?
To impress you?

I noticed you didnt use copper eve-drip.
So why are you worried about it here?
You know your copper valleys are maybe touching this steel eve drip right?
You know the roofing nails dealing with all this are maybe not copper, right?

I would leave his work alone.
I really dont think there is anything wrong.

Changing out the step flashings would mean removing the shingles too and you dont want that.
These shingles are bullet proof
And almost roofer proof once installed.
They are so tough they are practically impossible to repair.
They will laugh at your flat bar (pry bar) trying to dismantle them.
Like jabbing at a piece of stone that wont even chip.
This is what its like when they have aged a little for sure.
MAYBE it might be flexible enough at this time
To replace the roofing around the chimney without damaging the surrounding shingles.
But i am recommending not to do that.

I think the probability of over all damage to the roof to replace the roofing here is greater than the probability of a problem with dissociated metals here.

I really think you are ok.

If you dont believe me,
And you are convinced “something” should be done about it.
At worst case, these shingles and step flashing
Shouldnt be touched.
you could remove the counter flashing.
Cover the step flashing with a slip sheet
Like some smooth self-adhered
Then install new copper counter flashing
because the other copper will be ruined removing it) :frowning:

Again, please just leave this alone.

Edit… been thinking some more.
The roll of material you have laying on your roof in the other thread next to the chimney
Is the exact type of material i am suggesting for the slip sheet.
So i believe this may have already been done.

I think youve got a fine roof!
Nothing to worry about.
I hope my post has left you with more confidence in your roof.
And not less.

Im sorry you had to see the mismatching step flashings. Only an eye-sore for a short while.
I know it was very very irritating.
It would have been very irritating to me also
I just would never allow one of my homeowners to see it.
I would have at least spray painted the mill finish black immediately
Or put the cover sheet on immediately.
Even if i didnt have immediate access to finish and install the new copper counter-flashing.

I think you have a fine roof.
I would be proud of it and know its going to last your lifetime.


I use scrap flat stock for steps,so sometimes my step pile is very multi coloured. I had one lady come out and comment on it,and I joked around and pretended not to see it. She was visibly upset until I explained it all gets covered

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I usually agree with roof_lover but not on this one. Something should be done about it. I know copper will corrode those aluminum steps. I can’t say for sure if it will happen before the shingles wear out, but since it’s an area that would cause massive issues if I it does I wouldn’t take the risk (and the homeowner shouldn’t have to). This doesn’t look to be a cheap job from a cheap company, so if they said they would use copper flashings they should do it correctly.


So what happens if it rains and this chimney isn’t finished?

You are right
But i saw in your other thread, where the copper counter on the one story is complete.
Is it still not complete on the 2-story?

They may have temporarily sealed it in some way.
I would call and ask.

Say you noticed the counter flashing not done yet along with the hip and ridge and what they did to keep it from leaking until they came back.
If they didnt do anything, , or they are unsure , that should prompt them to make haste to come back quickly.

A risk even if the steps were covered with a slip sheet first?

It will still be getting water run off from the copper onto the most venerable place of the aluminum step flashing, even if they are not in direct contact.

It is possible to leak if left as is but would likely take an extreme amount of rain as it currently is.

this is one chimney which I assume is complete? The other chimney is the one with the mismatched step flashing. And it’s supposed to rain. Where is the missing hip and ridge? Is that the area behind the chimney? Thanks so much for your help!

Galvanic-Corrosion_2.png (1228Ă—916) ( Galvanic chart

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