Nail Straight Rows on Plywood by Following Its Mill Lines

The Problem

A wandering nail row on sheathing means misses — fasteners that skip the stud or joist below and hold nothing. Snapping a chalk line for every row fixes it, but on a full sheathing job that's a lot of snapping.

The Technique

1. Look closely at the face of the sheet. Sheathing plywood carries faint, dead-straight parallel lines from manufacturing, spaced about every half inch across the sheet.
2. Drive your first nail into the framing at one edge of the sheet and your last at the other, locating the stud or joist as usual.
3. Pick the mill line that runs through (or nearest) both nails, and follow that one line for every nail between them.

The line does the job of a chalk line that's already printed on the sheet — you're only borrowing it once your row is registered on the framing at both ends.