Proper Ventilation

I know that proper ventilation is important to the life of the roof and the warranty . I would like to know how many roofers actually calculate to proper amount needed and present this to the HO. I sure it is easier to sell the roof without having to add extras to the price of the roof since improper venting won’t show up until the roofer is long gone. I was just wondering what you guess was in this area.
Thanks,
Jay

If the roof has functioning intake all I do is remove power vents, turbine vents, & turtle vents, and install ridgevent on the entire length of all ridges.
Haven’t had a single issue doing it this way for over 15 yrs.

If the roof doesn’t have functioning intake I bid to repair it so that it does function correctly.
I then use ridgevents as stated above.
There are rare instances where I will deviate from the use of ridgevents but generally speaking ridgevents work the best in my area.

We pay attention to ventilation a lot. It’s one of my biggest selling features. We end up changing some aspect of the ventilation on probably 75% of the roofs we do. Usually because of lack of intake or multiple types of exhaust on one roof (ridge vent with box vents or power vents or a lot in our area is anything else along with gable vents. We close up A LOT of gable vents) My biggest thing with it is that it’s required under the manufacturer’s warranty. We’ve been in business for over 20 years and expect to be in business for at least another 100 (positive thinking!), so I don’t need to go replace any roofs for free because a warranty I issued through a manufacturer was deemed void because we didn’t do the ventilation right!