Purlins at a 45 degree angle still provide sufficient support for installation of the metal roof panels.
Roof sheathing ridge gap.
The last course at the top may need to be rip cut if the roof is not in 4 foot increments.
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.
Like you i usually see about 1 1 2 inches of gap for the ridge vent.
How should the sheathing meet at the roof peak when there will be no ridge vent.
If there were no signs of trouble due to the abnormally small cut out i d just note its presence.
Jim katen oregon.
It s a simple gable roof with vents at either end and a ridge vent.
The original builders had put a 1 inch strip of plywood to reduce the gap opening.
When using full sheets of sheathing i end up with a 2 2 5 inch gap from center on either side of the ridge beam.
Maintain ridge nailing by adding additional blocking set back from the ridge or by using vent holes see.
Rising along the underside of the angled purlin until it reaches a gap then rising up to the next purlin and so on to exit at the ridge or gable.
I have seen two thoughts.
Ventilation air follows exactly the opposite path.
I am a diy so could easily be wrong but the 1in strip at the top near the ridge doesn t seem like good practice to me.
This is a simple pitched roof line with ridge beam and rafters attached with slope hangers.
Begin applying the sheets from the bottom of the roof the eaves and work your way up to the ridge.
The ridge vent installed properly will work better than retrofitted roof vents.
It takes 36 nine 4 panels 8 gaps of wall before the panel creep has moved a full inch which is probably the absolute limit.
And i was advised that that gap should be protected by a home inspector.
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.
The gap size typically between 1 and 3 inches.
The house does not have an overhang.
Now wait a minute.
But where the wall sheathing meets the roof sheathing there is a gap of approximately 1 8 of an inch.
If sheathing the wall starting with the first panel in the middle rather than at one end it should be just possible to sheath a 36 length of wall without having to trim a panel to keep the end panels sufficiently over the studs for nailing.
Leave a slight gap as if the sheathing was cut a little short and install the sheathing to a matching edge no gap.
