The attic will hit R80. Brazelton is doing much of the traditional renovation work himself, with the help of his father and a few friends. He sleeps inside the unheated, unfinished house on a cot, sometimes with the family's two dogs for companions. The more complicated work is being handled by a professional builder, Ryan Stegora.
Go with an aluminum patch. Use aluminum rivits or screws. Avoid stainless or other metal screws due to the interaction of different metals. Use a sealant like 3m 5200 or Boatlife. Do not use fiberglass to patch aluminum. It just doesn't hold up well.
Cut the fiberglass panel using a circular saw with a carbide-tipped blade, a jigsaw with a metal-cutting blade, or a fine-tooth handsaw. When using a circular saw or a jigsaw with a standard up-cutting blade, cut from the back (unfinished) side of the panel; with a standard handsaw, which cuts on the push, or down, stroke, cut from the front side of the panel.