I have a folded copper roof over a 14′ curved bay window….painting the house this summer I noticed nails (copper?) coming out where it is fastened just under the drip edge…some gone completely…I thought I would replace all the nails with stainless steel screw, approx 1.25″, but am concerned about some type of funny corrosion between the 2 metals, like the green gook that forms on copper pipes…don’t want something running down and staining the white trim or awnings.
Any comments from previous experience??
thanx
By the way ..( in the “don’t build ’em like they used to dep’t”)…the top edge of this copper roof appears to be fastened/soldered? to a lead sheet that has been mortered into the brick, everything seems to be in great shape 45 years later…no leaks no caulk. NW Ohio climate. What ever happened to those guys?
Replies
Best hang on till Greencu comes along. I asked him about using copper nails for the ridge roll I am installing, and he is not recomending I use copper nails..they can withdrawl.
I think SS is fine..he's expert tho'.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Any comments from previous experience??
As Sphere says, greencu is the doctor.
That's galvanic corrosion you're fearing. I read up on it before siding my place with copper, including area effect. Used nylon tee washers to isolate the copper from the stainless screws. Then I ran out just before I finished. PITA to get the first 1k so I figured I'd do a little experiment. 5 yrs later, no sign of corrosion. Apparently we don't have the right air in central Va to create a problem, at least not very fast.
The next house we avoided the whole issue by figuring out how to use copper snap rivets instead of screws.
I'm less than enthused with the almost nonexistent barbs on copper nails, such that I only use toe nailed cleats under my copper roof. Brass screws wouldn't be an issue. Let me know if you want to find those tee washers. Far as I know there's one company that makes them.
Don't know your risk in NW Ohio, but I'd try the stainless screws and keep an eye on them for awhile. Or go with brass.
PAHS Designer/Builder- Bury it!
Apparently from what I've read and the galvanic chart, stainless steel is fine to use with copper. I have no personal experience mixing the two. When I've needed to face screw copper ( ridge roll, for instance ) I've used brass screws, but dislike them because of the tendancy of the heads to strip. If there is a problem between the two, the copper will win and in 45 years some one else will have to put in new screws.
I think brass screws would work if you're careful to drill appropriate size pilot holes and lubricate the screws. Another possibility would be marine bronze or silicon bronze screws. Stronger than brass and closer to copper on the galvanic scale. Probably expensive, too. Google for sources.
I'm for a copper nail to avoid Dielectric corrosion (find a ring shank nail) (Sphere!)
I got ring shank copper from Swan Secure:
http://www.swansecure.com/fasteners106/shoppingcart/roofingpage22.asp
They're called "slating nails" even though they're used for both copper and slate.
-- J.S.
http://www.abccatalog.com/store/listcategoriesandproducts.asp?idCategory=253 5 pages of different specialty nails.
You can buy them here, they'll probably have to order them for you though.
They aren't cheap you'll notice.
Joe H
I knew someone would be closer to the "flame" than me...I'm sure the guy on this roof will enjoy the benefits of your knowledge...perhaps even mine...
I'll help you out any time John & list you on my friends list, E- mail me some time...
Dave...(this credit to unknown) LIFE IS SO SHORT,YET THE CRAFT SO LONG TO MASTER