Tree Island Ind. Roofing Nails are large flat thin head nails with a short body. They are used for attaching asphalt, fibreglass shingles or sheet metal to wood. Shanks are smooth or ringed for increased pull-out strength. When installing roofing nails be sure to flush to the shingles. Avoid countersinking roofing nails as this can cause shingles to tear. Suitable for exterior applications.