Step 7 · Install Roof Sheathing

Starting at the bottom edge of the roof, lay sheets of plywood or OSB (typically 1/2-inch or 5/8-inch) perpendicular to the rafters or trusses. Stagger the seams between rows for strength. Secure the sheathing with nails or screws, spaced appropriately according to code (usually every 6 inches along edges and 12 inches in the field). Ensure there are small gaps (about 1/8 inch) between sheets for expansion.