Can The Edge Vent be used on a mansard roof?

Installing The Edge Vent at the transition of a mansard roof would be fine.

Installing The Edge Vent at the transition of a mansard roof would be fine. The only concerns would be for projected dormers extending above the transition creating breaks in the linear application of the vent which would cause several gaps in the ventilation line and create leak points due to the presence of the vent in several valleys. Small sheet metal drip edge (tee shaped) would also be helpful underneath the vent to prevent wind-blown rain from entering the vent coming from the lower roof decking. It's acceptable to install The Edge Vent at the low pitch portion of mansard and gambrel roofs due to the lower portion of these styles being nearly vertical. This keeps the possibility of wind-blown rain to a minimum. There is additional information about this on campus of Air Vent University on airvent.com (see "Lesson Plans").