How Big Should An Attic Access Be

According to the 2006 international residential code r807 1 attic access homes with combustible.

How big should an attic access be.

Tuesday january 28 2020. Vent size for an attic. If your attic floor has a vapor barrier you will need one square foot of nfa per every 300 square feet of attic floor area half of that will be intake half for exhaust. The attic may be accessed through a scuttle door or attic hatch usually located in a closet or main hallway.

Select a closet ceiling or hallway ceiling with good floor space underneath since you will need to use a ladder to access your attic. What is the minimum size for attic access opening. A home s attic access such as an attic hatch pull down stairs or knee wall door often goes uninsulated and unsealed creating one of the biggest holes in the thermal and air barrier between the attic and conditioned space. The purpose of attic ventilation is obvious in the summer when hot air collects in the attic and makes the entire house uncomfortable.

If the opening is located in a wall the 30 inch dimension must be vertical. If the access is located in the ceiling the minimum unobstructed headrom above the opening must be 30 inches measured vertically at some point over the access. The rough framed opening. Whether the attic access is an attic hatch pull down stairs or a knee wall door you should install insulation with the proper r value for your climate based on the department of energy s recommendations.

Move a stud finder across your ceiling to locate the joists. If there is no vapor barrier double it to one square foot of nfa for every 150 square feet of attic floor space half for intake half for exhaust. You ll notice in the photo below that interior door jamb stock does not have any kind of weather stripping in it for obvious reasons. Also to find out where your home might be losing energy consider conducting an energy audit.

This generally comes in 7 lengths and you will need three pieces of it for a standard sized attic access hatch. The minimum size for an attic s access building codes. Mark each joist location with a pencil. The rough opening cannot be less than 22 inches by 30 inches and must be located in a hallway or other readily accessible location.

The 2012 international residential code requires an attic access opening for attics with an area greater than 30 square feet and a vertical height in excess of 30 inches.