Preparing a deck for copper installation involves careful attention to the base materials to ensure the lifespan and performance of the copper. The sheathing beneath the copper should be structurally sound, flat, and made from a durable material like plywood or oriented strand board (OSB). This provides a stable, uniform surface that prevents the copper from buckling or warping over time. The deck must be as flat as possible because copper roofing is thin and flexible, and irregularities underneath can cause dents or uneven stress points that might lead to premature wear or leaks. Before installation, visually inspect the deck for soft spots, rot, or gaps, and repair or replace damaged sections. Ensure the sheathing is clean and free from debris that could cause unevenness or damage the copper.
Fasteners used under copper decks are just as important since copper can be easily scratched or punctured by inappropriate hardware. Stainless steel or copper fasteners are the safest choice to avoid corrosion, which can stain or damage the copper over time. Avoid using galvanized nails or screws, which can cause a chemical reaction leading to discoloration or accelerated corrosion. As a homeowner or DIYer, you can check the deck’s flatness using a long straightedge or level on the surface to identify uneven areas that need attention before copper installation. If you notice any questionable spots or the deck isn’t perfectly flat, it’s wise to call an experienced roofer who understands metal roofing specifics. When you reach out to a contractor, consider asking, “How do you ensure the decking is adequately prepared for copper to avoid future problems?” and “What type of fasteners and under-layment do you recommend to maintain the copper’s warranty and longevity?”