Unsealed Shingles

Unsealed shingles are common at asphalt shingle roofs. Asphalt shingles have an adhesive strip so that they the overlying shingle bonds near its lower edge with the shingle below. This enhances wind resistance as it helps prevent the shingle from being lifted and damaged by wind. Factors that can contribute to a adhesive strip failing or improperly bonding includes manufacturing errors such as defective sealant or a sealant adhesive being applied too scantily over the shingle.  Other problems beyond the control of the manufacturer include over-storage (warehousing) of the shingle or installing them in cold weather, which can contribute to the shingles not fully bonding.