Nail Pops and Exposed Nails: Small Roof Problems That Cause Leaks

What a nail pop is

A nail pop happens when a roofing nail backs out of the decking and pushes up on the shingle above it. The raised shingle can break its seal, and eventually the nail head can wear a hole through the shingle. Water then follows the nail shank straight into the decking.

Why nails back out

• Decking that expands and contracts with heat and moisture.
• Nails that missed the rafter or decking, or were driven at an angle.
• Nails driven into wet or damaged decking.
• Underdriven nails that were never seated.

Exposed nail heads

Some nails are meant to be exposed only if they're sealed — at ridge caps and some flashing — but exposed nails anywhere else are a leak waiting to happen. High nailing above the manufacturer's nailing line also weakens wind resistance. See shingle nailing patterns.

How they're repaired

Pounding a popped nail back down rarely holds. The repair removes the nail, places a new nail nearby in solid wood, seals the old hole, and replaces the shingle if it has been punctured or creased. If many nails are popping across the roof, the cause is often the decking or the original installation, which may point toward larger repair or replacement. See repair vs replacement and signs your roof needs replacement.

Signs from the ground and the attic

Small bumps in rows across a slope, shingles that won't lie flat, or nail tips with rust rings and drip marks in the attic.

Call for roof repair to have them fixed before they turn into wet decking.

Frequently Asked Questions