# Should I replace counterflashing?



## jeffw (Apr 13, 2008)

I am a homeowner and need to replace the roof of the house I am purchasing. The house is in southern NY state and was built in 1956. I am guessing the copper chimney flashing is original. 

I received multiple estimates and all but one of the roofers told me that I should replace all of the chimney flashing, both counter and step. 

One roofer, who in my opinion, seemed a bit more knowledgeable than the others (but maybe I'm being fooled by his salesmanship), told me that he would not at all recommend replacing the counter flashing ("I wouldn't even do it on my own house"), as it is in good shape and since it might be a through wall flashing, I am asking for trouble. He told me I should only have the step flashing replaced when replacing the rest of the roof. 

I don't mind spending additional money, if needed, to get the job done the best way. 

If I am replacing the rest of the roof and step flashing, should the counter flashing also be replaced? 

How long does copper flashing last? If it is already 50 years old (but in good shape), will I be able to get another 30 years out of it? 

Thanks.


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## oldfrt (Oct 18, 2007)

Hey Jeff,

If most of the estimates included replacing the counter flashing there may be a reason that they would go through the trouble to do it,since it requires cutting into the mortar or brick to re-install.I know a few roofers that are dead set against replacing counter flashing because of the labor involved.It's like they don't figure it to be part of their job.

I believe it is part of a complete roof system and some roofers may not warranty their work if the counter flashing isn't done by them.

That being said,there is always the possibility that the chimney was re-pointed or rebuilt recently,and the flashing may be alright.In this case,make sure that the step flashing installed is also copper,as tin will deteriorate in a short time when it comes in contact with the copper.


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## Ed the Roofer (Jan 27, 2007)

For a very accurate answer to your question, the best thing would be to post a few photos, one from each side, to see what kind of shape the existing counter-flashings are in.

If the material is tight and well embedded into the mortar joints or even properly surface mounted, then it may not be necessary.

Also, the Baby Tin step flashings that MUST be used and the nails to attach them and the shingles to them, MUST also be made of copper.

If standard aluminum baby tin step flashings and galvanized nails are used, they will be chemically eroded by the Galvanic Reaction of the extreme dissimilar metals in contact with each other.

Ed


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## jeffw (Apr 13, 2008)

Attached is a photo of the existing flashing. I couldn't get a view from the back as a tree is blocking it (and I didn't climb up there)

Based on what you see:
1) Can you tell if this is a through the wall flashing?
2) Should this counter flashing be replaced?

Thanks so much for your assistance.


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## Ed the Roofer (Jan 27, 2007)

I can't tell from my screen whether or not that is Lead Coated Copper or another type of metal.

It looks like the top edges are embedded into the horizontal mortar joints, but because of the amount of metal pushing away from the vertical joints, they might not have cut them in, or cut them in deep enough.

I can not comment about the quality remaining at the base of the flashings, because they are coated with roofing cement, which is many roofers talent level for doing what they consider to be a counter-flashing.

Because of the soldered corner or turned around corner, it "May" be difficult to remove and reinstall new baby tin step flashings behind the sheet metal that is attached to the masonry surface.

If you do decide to keep the existing counter-flashings in place, your roofer will have more room to work with, since the height of the roof surface wil go down, especially if it is a multi-layer tear-off. They "Should" be able to install new baby tins with that extra room.

Also, they should be scraping out the old caulk and loose mortar from the reglets and filing those channels back in with either new mortar or a high grade of caulking sealant, preferably, Geocel, Vulkem or NP-1.

Ed


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## the roofing god (Aug 2, 2007)

YES REPlace the counter flashing!,1st waterproof the juncture betwween the roof and wall w/Ice and water shield so it goes 3-4 " up the brick,then install new flashings---that `s old 16 oz. copper which has reached a green patina


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## johnk (May 1, 2007)

TRG-doesn't that green patina help protect the copper


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## the roofing god (Aug 2, 2007)

yes it`s actually bacteria that grows on it,but the bottom was tarred,and you should be laying the ice shield 3-4 inches up the wall to deal with wind driven rain or ice,In the event it is a thru wall flashing,it is easy to cut the existing flush to the brick using a grinder with a diamond blade---In my opinion ,any copper flashing that had to be tarred,has problems ,and should be replaced


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## johnk (May 1, 2007)

TRG-I'll admit your right....again.Geez that's hard for me


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## johnk (May 1, 2007)

Nobody noticed that there was no flashing at the base of the chimney.I missed it at first as well,eyes were focused on all that tar.(And Axiom pointed it out on another forum)


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## Dale Chomechko (Mar 11, 2008)

*Chimney counter flashing*

I usually don't replace it if its in good shape. If the mortar & brick are good we sometimes replace the step, wall & backpan flashing Then over all of it install a custom gumlip flashing. In this case it's copper which should be used only with copper. As has been pointed out there is no counter flashing in front. Best solution is probably cut this one out and replace it.


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## the roofing god (Aug 2, 2007)

have seen it in person,and it definitely needs replacing


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