Roof Insulation Air Flow

Without high levels of attic or roof assembly insulation warm air will flow through the ceiling and roof to the outdoors in the winter.

Roof insulation air flow.

It is important to block these spaces. Channel air flow channel air flow is an indirect path between openings in the building envelope. In addition insulation baffles must be installed at the point where the attic floor meets the roofline to prevent the attic insulation from migrating into the cavities and restricting the airflow from the soffit vents. Air should be tunneled from the eaves behind the insulation that is installed between the roof rafters and allowed to exit at the peak or at gable vents.

As the air in the baffles heats up it can flow to the peak and out the roof vent. Concrete block with mortar joints can support diffuse air flow two ways. Through the block and through cracks that form in the mortar joints. Plastic cardboard and styrofoam baffles are available at home stores which can be installed between the roof sheathing and insulation to allow unobstructed air flow from the eaves to the unheated space.

To control these different types of air flow ensure that the building envelope is airtight. Similarly in hot weather conditions warm air will infiltrate into the living are attic temperatures may reach 140ºf 60ºc and more. These openings are often a space hidden from view where a wall and the roof deck interface. To counter these problems baffles are installed to keep a small space between the insulation and the roof deck.