Place Shingle Nails So the Seams Above Never Drain Onto Them
The Problem
Every nail in a shingle roof is a hole held closed by the shingle above it — unless water finds a reason to dwell there. The butt joints between shingles are exactly that reason: rain concentrates in the seam and runs down it in a channel. Put a nail in that channel's path and you've built a slow leak into a brand-new roof.
The Technique
Think about where each seam above will send its water before you drive the nails below.
- Nail at the standard positions across the shingle, with a nail about an inch in from each end.
- Before nailing the course, look up at the seams in the course above: every butt joint is a water channel pointed downhill.
- Place your nails so none of them sits in line below a seam. Where the joint above "drops" its runoff, there should be solid shingle — the water running out of the seam crosses mat, not a nail head.
Do that consistently and the runoff concentrating at every joint travels over unbroken shingle the whole way down — the nails stay dry in the dead zones between seams.
Pro tip: This is the roofer's version of a habit worth having everywhere water runs: trace the drip path before you make the hole. Shingle layout offsets the joints course to course for exactly this reason — the nailing just has to respect the same logic.
Safety note: Roof work means fall protection — harness and anchor on anything with real pitch or height, footwear with grip, and no working a wet or frosted roof. No nailing pattern matters more than coming back down the ladder in one piece.