Roofing Glossary

Overdriven Nails

Overdriven nails are fasteners driven too deep — the nail head breaks through the shingle's fiberglass mat instead of sitting flush on the surface. A nail that has blown through the mat has almost no holding power; it is a hole, not a fastener.

Overdriving is a nail-gun pressure problem: too much air pressure, or firing at an angle, punches the head through the shingle. The damage is hidden under the overlapping course above, so it goes unnoticed until shingles start slipping or blowing off.

The mirror defect is underdriven nails — heads standing proud — which push up the overlapping shingle and eventually wear through it. Correct depth is flush: head flat on the shingle surface, not countersunk, not raised.

Why It Matters

Like high nailing, overdriving is invisible after installation and devastating in wind. Both are pure workmanship issues — another reason the crew's skill matters more than the shingle's marketing.

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