Attic Insulation Ventilation Balance

To keep the ventilation space clear above soffit vents special baffles need to be installed before the insulation goes in.

Attic insulation ventilation balance.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Balanced soffit to ridge and unbalanced soffit to soffit only. Both can be added to uninsulated attics or layered over existing material. Loose fill or batt the common term for blanket insulation.

Calculate net free vent space. Once you ve decided which type is best for you examine the material options and prices to home in on the right product. The general rule of thumb is to have at least one square foot of vent space for every 150 square feet of attic area. The balance of the required ventilation provided shall be located in the bottom one third of the attic space.

We evaluated two ventilation schemes. In most cases the best type of attic insulation will be blown fiberglass or blown cellulose insulation. The modeled attic had gabled construction measured 50 by 27 feet with a 4 12 roof slope and had r 30 insulation in the ceiling. Building codes typically require 1 square foot of venting space for every 150 square feet of attic space.

For help achieving the right balance between ventilation and insulation in your charlotte area home please contact us at ross witmer. Where the location of wall or roof framing members conflicts with the installation of upper ventilators installation more than 3 feet 914 mm below the ridge or highest point of the space shall be permitted. Our experience dates back to 1945. An attic fan is only recommended if your home is sealed off from the attic and the soffit vents are unobstructed.

For diy attic insulation you ve got two choices. For an attic ventilation system to perform properly it needs a balance of intake and exhaust. After successful completion the student should be able to perform an inspection of the attic insulation ventilation and interior of a residential property according to the internachi residential standards of practice. This cools your hot attic by drawing in air from outside and pushing overheated air to the exterior.

A section of this book lists the particular parts of. Unfortunately too many houses have sufficient exhaust but inadequate intake. For comparison we also evaluated a sealed attic one without vents at the soffit or the ridge. If there s a vapor barrier beneath the insulation it can be 1 300.

The potential problems vary with the type of exhaust vent being used.