Roofing Glossary

Shingle Curling

Curling is what happens when the edges of asphalt shingles lift and turn upward, away from the roof surface. It is one of the most recognizable signs of an aging roof — and one of the clearest signals that replacement is approaching.

Curling has two main forms. Cupping is when the edges turn up and the center stays down, like a cup. Clawing is the reverse: the center lifts while the edges stay nailed, like a claw. Both are driven by the same forces — the asphalt mat shrinking and drying with age and heat, moisture cycling in the attic, and poor ventilation accelerating the process.

Curled shingles cannot seal properly, which leaves them vulnerable to wind uplift — a curled edge is a handle for the wind to grab. Once curling is widespread, repairs stop making economic sense.

Why It Matters

Isolated curling can sometimes be addressed, but widespread curling across slopes means the shingles have reached the end of their functional life. It is one of the key signs you need a new roof.

What to Watch For

• Shingle edges visibly lifting across large areas
• Shingles that no longer lie flat or seal to the course below
• Curling concentrated on south- and west-facing slopes (heat-driven)

A Maryland Note

Maryland's hot, humid summers and strong sun exposure on southern slopes accelerate the drying and shrinkage behind curling.

Questions about your own roof? Request a free estimate or call Nucci Brothers Roofing at (301) 458-1003.