How To Make Attic Ventilation Baffles

Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter.

How to make attic ventilation baffles.

The deeper the insulation the longer the baffles have to be. When set into place and sealed with spray foam the vent baffles are insulated and air sealed. 1 2 inch foil faced rigid foam insulation. 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.

Measure the distance between your rafters and purchase enough rafter vent baffles to install one over each. Locate the soffit vents in the eaves of your home. You will need a baffle for each space between the rafters. In a traditional cape cod house with 4 foot kneewalls there are two ways to install ventilation baffles.

It may be easiest to locate and mark them from below. Attach a headlamp to your hard hat to free up your hands as you work. Staple the edges into place with the staple gun making sure they are lined up correctly and securely. Put on your safety gear.

The preferred way is for the baffles to begin above the ventilated soffit and extend all the way to the small attic above the second floor ceiling. Be careful of any roofing nails that may be sticking out of the rafters or bay. Put the straight est edge of the block at the baffle fold. Baffles establish a channel for air to circulate between the insulation and the roof sheathing.

Affix the insulation block to the baffle scissors and double sided carpet tape. As with attic floor insulation moisture and heat removal are the reasons for creating proper air. Set the baffles and a loaded staple gun inside the attic opening and boost yourself into the attic. Rafter baffles are sheets of plastic foam or cardboard that fit between the rafters in your attic to prevent moisture accumulation and add insulation to your home.