Insulating A Roof Without Soffit Vents

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.

Insulating a roof without soffit vents.

Typically you would have a gable vent on each end of the attic. Aside from the technical aspects of insulating and venting an attic without a soffit this is a project that requires both experience and expertise. They call this a venting drip edge. With old homes it can be very difficult to properly ventilate the attic for a variety of reasons.

With spray foam unlike with loose fill or batts you must cover the soffit vents they aren t needed to keep the roof cool. 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. To begin with the attic must be sealed to make the space airtight and to ensure that there is no air leakage. 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.

Then cover the foam with drywall as required for fire safety. 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. In cases where there is no under roof venting system no soffit intake vents no ridge vents a hot roof design is followed. 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.

For an attic without soffit vents you may have the option to use gable vents instead. Venting solutions for roofs with no overhang or soffit. Smart vent a special roof eaves vent product that provides a 3 4 opening about 6 above the top of the roof drip edge. The venting drip edge seems to be the easiest and most common way to go.

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