Insulating A Roof Without Soffit Vents

To begin with the attic must be sealed to make the space airtight and to ensure that there is no air leakage.

Insulating a roof without soffit vents.

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. Then cover the foam with drywall as required for fire safety. They call this a venting drip edge. Typically you would have a gable vent on each end of the attic.

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 venting drip edge seems to be the easiest and most common way to go. With old homes it can be very difficult to properly ventilate the attic for a variety of reasons. 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.

With spray foam unlike with loose fill or batts you must cover the soffit vents they aren t needed to keep the roof cool. For an attic without soffit vents you may have the option to use gable vents instead. These specialty vents do not affect the. Smart vent a special roof eaves vent product that provides a 3 4 opening about 6 above the top of the roof drip edge.

Venting solutions for roofs with no overhang or soffit. 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. 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. 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. Weird attic layouts may be a part of it.