Roof Sheathing Ridge Gap

Now wait a minute.

Roof sheathing ridge gap.

This is a simple pitched roof line with ridge beam and rafters attached with slope hangers. But where the wall sheathing meets the roof sheathing there is a gap of approximately 1 8 of an inch. The gap size typically between 1 and 3 inches. Vents evenly spaced underneath the roof provide intake.

It s a simple gable roof with vents at either end and a ridge vent. Multiply it by 18 square inches the net free air per foot of ridge. Ridge vent installation in new construction the roofing contractor leaves a small gap at the peak of the roof when installing the roof sheathing. 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.

This gives you 450 square inches of total exhaust. So you re talking about you re going to reroof and you have a gap between the wall sheathing and the roof sheathing. To calculate an example of exhaust and intake use 25 feet of roof ridge vent. Begin applying the sheets from the bottom of the roof the eaves and work your way up to the ridge.

How should the sheathing meet at the roof peak when there will be no ridge vent. 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. Leave a 3 mm 1 8 inch gap between the osb panels to allow for expansion. The last course at the top may need to be rip cut if the roof is not in 4 foot increments.

Leave a slight gap as if the sheathing was cut a little short and install the sheathing to a matching edge no gap. The house does not have an overhang. Maintain ridge nailing by adding additional blocking set back from the ridge or by using vent holes see. I have seen two thoughts.

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.