What are rafter baffles and why do they matter?

Rafter baffles — sometimes called insulation baffles or vent chutes — are channeled panels installed between rafters at the eaves that create a clear airway from the soffit intake up to the attic space above the insulation. Their job is to keep that intake air pathway open so intake air can actually reach the attic and do its job.

Why they matter becomes obvious the moment blown-in insulation enters the picture. Blown-in insulation is an excellent thermal performer, but it’s also a loose material that migrates toward the eaves over time — exactly where your intake air needs to enter. Without baffles, blown-in insulation gradually fills the rafter bays at the eaves and blocks the intake path entirely. The soffit vents may be perfectly intact, but the air can’t get past the insulation to enter the attic. You have the appearance of a ventilated roof with none of the function.

Our approach is straightforward: if a house has blown-in insulation and we’re replacing the roof decking, we install rafter baffles at the eaves where soffit intake exists. This restores and protects the intake air pathway before the new deck and roofing system go down. If soffit intake doesn’t exist, we install on-roof intake venting from Lomanco — a purpose-built product that brings intake air in through the roof plane itself rather than through the soffits — so the ventilation system has what it needs regardless of what’s happening at the eaves.

It’s one of those details that’s invisible when it’s done right and expensive when it’s skipped.