In the restoration of an old home, if one decided to use copper for the gutter material, under the copper sheeting in a gutter around the edge of the house does there need to be something isolating the copper that the wood of the roof?
I wouldn't have thought so. It'd be more important to keep the copper from touching other metals like aluminium. We have copper gutters and they're wonderful .we watch the neighbours getting their gutters replaced and feel smug .and they look really nice especially when they oxidise (c;
With the price of copper the gutters will be worth more than the house. But the answer is no reason to isolate them but you do need to paint the facia behind the gutters to protect it from water. Now if you have aluminum facia there could be some electrolytic action between them and one of the other would deteriorate but I am not sure if that is true, but any 2 metals can have electrolytic activity.
If the wood is pressure treated you must separate them because the the substance used to treat the wood could possibly have a negative affect on the copper i.e., corrosion. I might suggest that, in any condition, it would be a good idea to separate the two. In case you choose to do this you could use a membrane manufactured by the Grace, Corp. made specifically for this purpose.
