Begin at the eaves.
Attic ventilation needs a way for outdoor air to enter as well as a place for air to leave. Covered or blocked intake openings can limit that path even when roof exhaust vents are present.
What a baffle does.
A suitable baffle preserves a channel between insulation and the underside of the roof near the eaves. It helps keep loose-fill insulation from obstructing the ventilation route.
Check the opening behind it.
A baffle does not create an outdoor intake through a closed soffit or a blocked assembly. We consider the available openings, the eave construction and the roof ventilation arrangement together.
Connect the details. Insulation, ceiling air sealing, attic ventilation and household exhaust are considered together when planning the scope.

