While it is very true that you can't just drape a tarp over a gap in the roof, tack down some nails and call it good enough, some form of fastener is required to secure the tarp while causing the least damage to the "healthy" areas of the roof. The owner of Bros. Roofing & Repairs LLC is a preferred contractor with most insurance companies in South Carolina, though, and our method for securing the tarp is always accepted and appreciated by insurance companies. We wrap the edges of the tarp around boards to pull it taught and then carefully screw the board itself into the roof deck or the underside of the eaves.