How Big Should An Attic Access Be

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.

How big should an attic access be.

Also to find out where your home might be losing energy consider conducting an energy audit. Vent size for an attic. The minimum size for an attic s access building codes. Your joists should be 16 to 24 inches on center.

This generally comes in 7 lengths and you will need three pieces of it for a standard sized attic access hatch. 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. Select a closet ceiling or hallway ceiling with good floor space underneath since you will need to use a ladder to access your attic. Move a stud finder across your ceiling to locate the joists.

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. A inch gap around the perimeter of a standard pull down staircase can potentially leak the same amount of. Tuesday january 28 2020. Mark each joist location with a pencil.

If the opening is located in a wall the 30 inch dimension must be vertical. But venting has an equally important. The purpose of attic ventilation is obvious in the summer when hot air collects in the attic and makes the entire house uncomfortable. 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.

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. 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. 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 rough opening cannot be less than 22 inches by 30 inches and must be located in a hallway or other readily accessible location.

What is the minimum size for attic access opening.