Roof Sheathing Ridge Gap

Ridge vents 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.

Roof sheathing ridge gap.

Roof trusses must be dry when sheathing a roof with osb to prevent mold growth in the roof and coverage gaps as the trusses dry and shrink. Multiply it by 18 square inches the net free air per foot of ridge. Leave a 3 mm 1 8 inch gap between the osb panels to allow for expansion. This gives you 450 square inches of total exhaust.

Begin applying the sheets from the bottom of the roof the eaves and work your way up to the ridge. Vents evenly spaced underneath the roof provide intake. It is important here that the sheathing at the eave line be exactly perpendicular to the rafters so that the sheets will meet at the centers of the rafters. Now wait a minute.

Ridge vent installation in new construction the roofing contractor leaves a small gap at the peak of the roof when installing the roof sheathing. Avoid butting osb panels tightly. How should the sheathing meet at the roof peak when there will be no ridge vent. I have seen two thoughts.

It s a simple gable roof with vents at either end and a ridge vent. But where the wall sheathing meets the roof sheathing there is a gap of approximately 1 8 of an inch. Maintain ridge nailing by adding additional blocking set back from the ridge or by using vent holes see. Stagger the panels over the roof with 2 supports between panel ends.

This is a simple pitched roof line with ridge beam and rafters attached with slope hangers. Leave a slight gap as if the sheathing was cut a little short and install the sheathing to a matching edge no gap. To calculate an example of exhaust and intake use 25 feet of roof ridge vent. And i was advised that that gap should be protected by a home inspector.

The gap size typically between 1 and 3 inches.