Proper Attic Ventilation Requirements

You can go as low as 1 300 of the attic floor area for attics which have a continuous vapor barrier below to a high of 1 5 in inches x the floor area in feet.

Proper attic ventilation requirements.

Rafter vents should be placed in your attic ceiling in between the rafters at the point where your attic ceiling meets your attic floor. The following are the requirements taken directly from the irc. Look at your eaves and roof. If you don t see any attic vents on the roof or in the eaves you need to add some.

A hot ceiling tells you that the attic is acting like a solar oven raising your cooling bills and. You can also contact your local municipality to check on building code in your area. The majority of the requirements related to attic ventilation have not changed much from the previous editions. Your roof vents may not look.

In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. The ventilation ratios go according to attic floor size not roof size. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.

Of vent for every 300 sq. Proper ventilation necessitates that fresh air is able to find its way in the attic space while allowing stale air to get out. This is accomplished through the placement of ventilation near the bottom of the attic space at the soffits or eaves intake and at the top peak s or ridge s of your attic space exhaust. Touch your ceiling on a warm sunny day.

According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Measure the length and width of the attic floor space to be ventilated. That is a huge difference in allowance.

Most building codes require a ratio of 1 150 ventilation space to attic floor space.