From the roof he will cut a hole the same size as the diameter of the vent.
How to properly install roof hvac.
It s common to place the heating ventilating and air conditioning hvac systems for large buildings on the roof.
Cover the entire flange with shingles to integrate it better into the roof.
Place the first screw about 7 inches from the bottom and each subsequent screw about 18 to 24 inches apart along the vertical run.
Install the roofing screws vertically along each rib in the panel.
Press new shingles onto the caulk and use nails at the top of each shingle to fully secure them to the roof.
If the gaps lined up water could get directly onto the roof sheathing and then seep in through a nail hole.
Place a line of roofing tar or caulk on top of the vent s flange or its bottom flap using a caulk gun.
Secure the screws but do not overtighten.
The washer under the screw head should seal to the surface of the panel without bulging or shifting.
Arrange the shingles so the ends and the tab notches do not lie directly above gaps in the shingle below.
Likewise it may not be advisable or possible to set the rooftop hvac unit directly on the roof especially if the building has a membrane roofing system.
From inside the attic your roofing professional will drive a nail about one third of the way down from the ridge between two rafters to mark the desired spot for installation.
Glue down shingles to cover the bottom of the vent.