How To Make Attic Baffles

The rigid foam is cut to be 2 inches wider than the space between rafters then 1 inch of foam is scored and folded over on either side of the foam creating standoffs that hold the foam away from the roof sheathing providing a space for air to flow.

How to make attic baffles. The book that helped us build and renovate. If your rafters are closer or farther apart than this distance it may be necessary to make your own rafter baffles. They come in several widths so purchase the baffle that fits between your rafters. Cut at least two 24 inch squares of inch plywood to use as seat boards when crawling out into the attic.

The picture below courtesy of the epa indoor airplus program which we provide builder verification services for helps show how the system works. Measure the distance between your rafters and purchase enough rafter vent baffles to install one over each soffit vent. Commercially made baffles can be purchased in 16 inch or 24 inch widths. You will need a baffle for each space between the rafters.

An attic baffle is simply an item to regulate the flow of air aka required roof venting and impede it the insulation from interfering with each other. Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter. Attach this roof and attic insulation treatment using foam baffles to ventilate insulate and channel cold and hot air to roof vents before insulation is add. When set into place and sealed with spray foam the vent baffles are insulated and air sealed.

Baffles should fit snugly between your rafters and extend from just over the vent at the wall plate up the rafter.