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TOPIC: Copper Roofs

Copper Question

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Installing a Classic Rib roof on a gambrel log home. ISO board and plywood sheeting. Toar off and re-felted. Have question about installing a copper chimmney cap and stack covers. In neither place will the copper actually touch the roofing. The stacks will have the gasket between the copper cover and the roof and the chimmney caps will have, well the chimmey between the copper caps and the flashing and roofin. The manufacturer says that the different metals should not come in contact with each other for the obvious reasons, but if they aren't touching will the moisture or run off from the copper cause any damage to the roof. Getting some mixed signals from that question. From what I understand the galvanic process required contact between dissimilar materials.
Guest User

10/17/2004
Yes, generally, you need contact for electrolysis. That said, though, run-off can also cause problems. I am assuming that the Classic Rib roof will have a good paint finish on it. That paint finish will provide good protection for the steel from the copper run-off. However, the copper run-off might cause visible streaking. Generally, I would suggest avoiding this type of thing. I am not so concerned about actual damage of the roof but rather I am concerned about aesthetics issues from the streaking caused by the run-off.
Guest User

10/17/2004
Hmmm... That was my concern exactly. Color is green and finsih is listed as MS Colorfast30 and Acrylic Coated Galvalume. Tough thing to guess, depends on the acid content of the rain as well I would guess. The run off should be dark though, and it should taper off as the copper ages. I'm leaning towards trying the stack cover over the winter prior to the chimmney cap to see how it goes. Would the streaking be something that can be washed off or would you expect it to stain? Thanks for the help.
Guest User

10/18/2004
Really, here's what I would expect: Metal roofs get some accumulated dirt on them over time. The amount and type of dirt depends upon several things including rainfall and also how many trees are around. Over time, this dirt can build up to a sort of grime and, if trees overhang the roof, the dirt could support biological growth. However, the run-off from the copper will carry ions (or something -- I never liked Physics that well) which will act to "clean" off this stuff. So, really, what happens is that you end up with clean streaks beneath the copper.
Guest User

10/18/2004
Well heck that doesn't sounds too bad. Already cleared the overhanging foilage out of the way. But there will be leaves and other frag from the surround trees. So more copper would be a good way to clean the rain and tree grime off? ha... Thanks for the information I think we'll go ahead and try the copper stack cover and chimmney cap and see how it goes. Doesn't sound like it'll do any physical damage, and besides copper will look bloody fantastic with a green roof. Thanks for the help.
Guest User

10/19/2004
we have a customer that is having troouble with ice daming and would like to have a de-icing cable installed. We are trying to find if there are copper straps avalible straps to afix it to the roof also was wondering if we could use stainless steel without causing damage. Other metals to copper is supost to cause decaying of one of the metals when touching. Please reply asap. Thank-you Trina
Guest User

1/20/2005
I would try the local plumbing store as they should have copper pipe straps that could be folded to work. To the best of my knowledge Stainless and copper do not react together.
Guest User

1/20/2005