Are sealants required with copper systems?
Most copper installations depend on self-flashed details requiring no sealants. Under some conditions, such as low roof slope situations, the use of sealants is recommended as a secondary waterproofing material. However it should be noted that copper will outlast most sealants and that in any details using sealants a regular maintenance and inspection program will become necessary. In general, butyl, polysulfide and polyurethane sealants are reasonably compatible with copper. Acrylic, neoprene and nitrile-based sealants actively corrode copper. Silicone sealants have a variety of success with copper, but their suitability should be verified with the manufacturer.
