Q: I enjoyed the article on copper roofing (“Installing a Flat-Seam Copper Roof,” May/16). I have always “pre-tinned” copper panels before installing them. Is this necessary?
A: Kyle Diamond, a partner in New Dimension Construction, in Millbrook, N.Y., responds: “Tinning” is the practice of applying solder along the edges of copper panels before bending them to create the interlocking edges that I describe in the article. Tinning helps to ensure that there are no voids in the soldered joints between the copper panels where moisture might be allowed to enter.
Tinning is essentially a way of creating a foolproof installation, and I’d recommend it as a good practice, especially for beginners. I have been soldering joints in copper roofing for years, and one of the biggest keys to creating successful and long-lasting solder joints is to control the heat of the soldering iron. I am also meticulous about cleaning the joints before applying the solder. Any contaminants in the joints, including debris such as sawdust, can be a recipe for failure.