Roof Sheathing Direction

Cover sheathing with.

Roof sheathing direction.

I assume this means the panel should be applied with the long dimension across the studs yet the builder had installed the long dimension parallel to studs. And scroll down to see more details on each with installation hints and tips below. It spans the rafters to support the roofing and in the case of panel sheathing such as plywood or osb it acts as a diaphragm with the walls to resist horizontal loads. Check the nailing surface is level step 2.

The surface stamp indicated that the strength axis of the panel ran in the long direction see photo below. Roof sheathing attaches to the surface of the rafters or trusses to form the structural skin of the roof. But if you snap it at 40 inches then the sheathing will not project over the subfascia or true fascia. Why is the strength axis important for roof sheathing but not for corner.

Align the long edge of the sheathing with the ends of the. Position the first piece of plywood or oriented strand board sheathing on the bottom edge of the rafter tails at one end of the roof. This opens the door to the possibility of water damage by letting gravity work against you. How to correctly install plywood or osb roof sheathing.

Wind loads perpendicular to a wall are similar to floor and roof loads and installing sheathing horizontally makes walls better at resisting wind pressure. On roofs and floors sheathing is installed perpendicular to supports because this is the orientation that results in the strongest roof or floor. When the roof sheathing is used as a structural diaphragm as it typically is in high wind and seismic hazard areas the structural integrity of the diaphragm can be compromised by a continuous vent see figure a below left. The main one is the structure turning into a parallelogram where the studs are no longer perpendicular to the ground.

The same policy goes for roof sheathing as for hanging drywall you get more strength by spanning more rafters joists studs and offsetting the joints. This solves two points of weakness. Ventilate the roof according to current building codes step 3. Properly fasten panels including fastening and spacing hints step 4.