Q: A fallen tree limb has punched a hole in our aluminum siding about the size of a baseball. The damage appears to be limited to a single panel. How do I repair this?
A: The trickiest part of repairing aluminum siding can be finding a replacement piece that exactly matches the existing siding profile. First, cut out the damaged section of siding using tin snips. Keep the cut 1/2 inch away from the top of the damaged panel, and avoid cutting the vertical seam between two panels. Cut a patch of siding from the replacement panel about an inch larger than the damaged area. Cut away the upper nailing flange from the patch so it will lay flat. File all rough edges smooth. Test the patch for fit, adjusting the lower lip with pliers as necessary. Apply construction adhesive around the back perimeter of the patch and glue in place. Tap securely with a wood block to seat the repair. Paint to match.
If you’re unable to find a matching siding panel, you (or a contractor) may be able to fabricate a patch from aluminum sheet by measuring the panel and folding a piece to match on a sheet metal brake.