Troubleshoot, Fix and Repair; How to Fix Leaks in a Corrugated MetalRoof. Fixing leaks in a corrugated metalroof starts with locating the source of the leaks. It is not easy to catch a leak on a metalbarnroof. Because of the texture of the material and the slope of the roof, the water never leaks down in a straight line. It can leak down the sidewalls or pool up in places. Since a barnroof doesn’t have many obvious places for water to pool, you need This is an edit to my previous message: There is no roof deck under the metalroof. In fact, nailer boards are underneath the metalroof. I would guess they are 1x8 spaced about a 1 1/2ft apart. Keeping a watertight roof on a barn is Each has different requirements for maintenance and repair, but all provide a watertight roof, Metalroofing, BarnRepair Have an old Barn that needs repair? Does it need Updating, New Roofing, or an Addition We repair existing damaged metalroofs. Expert advice on how to repairmetalroofing, including DIY metalroof inspection tips and information on how to seal leaks and seams on metalroofs.