How to Install OSB Panels on a New Roof

Locate the barge rafters, which are the two outermost rafters on each side of the roof. For instance, if you’re facing the flat side of a standard gable roof, the rafter farthest to your left is a barge rafter, and the rafter farthest to your right is a barge rafter.

Measure 48 inches up from the bottom of each barge rafter and make a mark on the top of each rafter.

Pop a chalk line between these two points. This is your guideline for installing the first row of OSB panels.

Position an OSB panel horizontally at one side of the roof, lining up the top of the panel with the chalk line.

Nudge the OSB panel inward 1/8-inch from the outside edge of the barge rafter. Although 1/8-inch isn’t a large space, it allows the edge of the OSB panel a little room to expand in high humidity.

Use a framing nailer to insert 8-penny nails every 6 inches through the OSB panel and into the roof rafters beneath.

Install the second OSB panel just as you did the first, lining up the top of the panel along the chalk line, but leave a small, 1/8-inch gap between the first panel and the second panel. Because the panels are 8 feet long, they will meet over the center of standard rafters that are 16 inches or 24 inches apart.

Continue installing OSB panels in the same manner until you reach the opposite edge of the roof. Measure and cut the final panel 1/4-inch shorter than the distance from the last panel to the outside edge of the barge rafter. This allows you an 1/8-inch gap between the new panel and the last panel, as well as an 1/8-inch gap between the end of the OSB panel and the edge of the barge rafter.

Start the second row of OSB panels right above the end of the first row and stagger the joint seams in the second row so they do not align with the seams of the first row. For instance, if you cut 4 feet off the last panel in the first row so it would fit, you can now install a full 8-foot panel directly above it, and the vertical seams from one row to the next will not align.

Stabilize the horizontal seams between the first and second rows of panels with H-clips. Position two H-clips between each rafter, sliding them over the upper lip of the first row of panels. When you set a panel on the second row, slide it gently downward until the bottom edge slips into the open ends of the H-clips.

Continue installing rows of OSB panels from one edge of the roof to the next in the same manner until you reach the roof ridge. Here, you will most likely have to cut the final row of panels lengthwise to fit.