What size nail is required when installing roof louvers (box vents)?

Here is some information about nail size when installing roof louvers (box vents).

The nail used to fasten roof louvers must fully penetrate the roof decking (accounting for the thickness of the sheathing, shingles and flange material). Also, if the Texas Department of Insurance (TDI) evaluation report states using a certain length nail, this would be the minimum length needed, where additional length would be required if the decking and roofing materials would not allow it to come through on the other side. As a note, the longer the nail the harder it is for the vent to be removed from the roof during a wind storm.