Insulating A Roof Without Soffit Vents

Install special roof intake venting products that work at the lower edge of the roof decking underneath the first course of shingles.

Insulating a roof without soffit vents.

Normal vented air likes to enter the attic lower down near the bottom third of the attic and as it passes through it will exit higher up near the top third of the attic space. These specialty vents do not affect the. With spray foam unlike with loose fill or batts you must cover the soffit vents they aren t needed to keep the roof cool. One great alternative to a soffit ventilation system is to install an intake vent right at the lower edge of the roof.

For an attic without soffit vents you may have the option to use gable vents instead. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. Then cover the foam with drywall as required for fire safety. In an attic without soffit vents you can add insulation in the corners and the wedges between the slope of the roof and the floor of the attic which serves as the ceiling for the room below.

The roof cavity between rafters can be filled with insulation followed by installation of a perfect vapor barrier followed by finish surface of drywall or whatever else. They call this a venting drip edge. The venting drip edge seems to be the easiest and most common way to go. Venting solutions for roofs with no overhang or soffit.

In cases where there is no under roof venting system no soffit intake vents no ridge vents a hot roof design is followed. Foam blocks airflow needs no vapor barrier and has a higher r value per inch than loose fill or batts so you ll get more protection with less depth. Aside from the technical aspects of insulating and venting an attic without a soffit this is a project that requires both experience and expertise. Typically you would have a gable vent on each end of the attic.

Weird attic layouts may be a part of it. If i had an older home without soffits i would strongly consider just completely air sealing the attic and adding foam insulation totally removing the need for ventilation.