DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   Roofing and Siding (
-   -   Siding (

samsr 02-15-2012 12:56 PM

Anyone had any problems with redwood siding coming in contact with copper roofing?

oldognewtrick 02-15-2012 01:45 PM

What type of problems are you having?

nealtw 02-15-2012 03:02 PM

Acid from the cedar eats the copper.

inspectorD 02-15-2012 03:07 PM

I have never seen any issues, but if someone used galvanized fasteners...there will be an issue.

samsr 02-15-2012 04:05 PM


Originally Posted by nealtw (Post 68003)
Acid from the cedar eats the copper.

Could you please give me clearer explanation as to your quote, I ask the question because I am installing redwood not cedar verticle siding above a bay window which I just put a new copper standing seam roof cover on and was told that if the redwood comes in contact with the copper something happens to the copper. Thanks for any information.

samsr 02-15-2012 04:15 PM


Originally Posted by oldog/newtrick (Post 67998)
What type of problems are you having?

I,m not having a problem yet, I am installing redwood verticle siding on a gable end over a bay window and the redwood will come in contact with the standing seam copper roofing on the bay window, one of my men was told that if redwood comes in contact withthe copper the redwood does something to the copper

nealtw 02-15-2012 04:48 PM

Redwood is not cedar. Redwood is ok and cedar is not.

oldognewtrick 02-15-2012 04:50 PM

We've used copper flashing with redwood siding and cedar shake for years without any issues.

nealtw 02-15-2012 06:07 PM

Shingles, if installed in direct contact with metal flashing, will wick water through capillary action under the leading shingle edge. The water will tend to remain in contact with the flashing and build up in acidity. This acid-laden water will corrode flashing in a linear fashion leading to "line corrosion" or pinholes in the flashing. The correct detail is to raise the leading shingle edge on a cant thus breaking the bond between shingle and flashing. Extensive details are included in CDA's Copper in Architecture Design Handbook.
I borrowed this from

All times are GMT -6. The time now is 11:32 PM.