How To Vent Attic Space

The building code lets you reduce that by half under some conditions but more roof ventilation is usually better.

How to vent attic space.

Following this closed cell spf was also installed to the underside of the roof deck. Screw holes through both flanges. With the help of an assistant raise the vent up to the soffit and center it over the cutout slot. To determine the area multiply the length times the width in feet.

First determine your attic area by multiplying the length by the width. A 30 x 40 ft. Then aim for about 1 sq. So if your attic is 25 by 15 you ll need 2 5 feet of vent space.

You can also contact your local municipality to check on building code in your area. Building codes and attic assemblies. Attic for example has an area of 1 200 sq. Staple the chutes in place.

The dormers and the attic space over the outside porch were sealed off from the rest of the attic by making a wall of plywood then insulating the wall with closed cell spf. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh. Building codes typically echo the administration s guidelines.

Then divide the total area by 150 to find the total amount of vent space needed for your attic. Be sure to wear long sleeves goggles and a dust mask. Space the holes 12 to 14 in. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

In some cases you may need to install a wind wash barrier of wood or plastic to close the gap between the top plate and the air chute to prevent wind from blowing into the attic. In of vent opening per 150 sq. When determining how to insulate this attic space various assemblies were taken into consideration and a hybrid combination of vented and unvented attic space was planned. Next lay the strip vent down on a flat wood surface such as a plywood sheet or long 2 x 4 and drill 1 8 in dia.

Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Ventilation helps maintain a healthy attic space both for your roof and for your family.