Tab shingles, a popular choice for many roofs, are flat, rectangular sections of asphalt shingle that overlap in rows. Common failure modes include curling, cracking, and blistering. Curling often happens when shingles don’t install properly or weather conditions cause them to lose flexibility, such as prolonged exposure to heat or cold. Cracking can take place because of fluctuating temperatures leading to material shrinkage and expansion, or due to impact from hail or falling limbs. Blistering appears as raised bumps and is usually from trapped moisture or a poor manufacturing process. These issues can allow water to seep under the shingles, which raises the risk of leaks and water damage beneath the surface. Simple diagnostics for homeowners include looking closely for these visible signs on the roof surface, especially after storms or seasonal changes.
Homeowners comfortable with walking roofs can safely check tab shingles themselves by using binoculars to inspect from the ground or gently touching shingles to test for brittleness, but never go up on a roof in bad weather or if it's steep and slippery. If you notice curling, missing tabs, or granule loss, it’s wise to call a professional roofer to evaluate the damage more thoroughly. When speaking to a contractor, ask “What specific causes do you see for this shingle failure here?” and “How will your repair or replacement method maintain my roof’s warranty?” A good roofer should prioritize fixing underlying issues like poor ventilation or old flashing, not just replacing visible damaged tabs. Ensuring the contractor uses compatible materials and follows manufacturer guidelines will help keep your roof lasting longer.