When attic access is required

This is the last graphic in the series concerning attic access. The IRC code provides guidance on how large an attic must be before an access is required. It was confusing to me so I made this graphic to help explain what it means.

Here is the IRC code:

R807.1 Attic access. Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that have a vertical height of 30 inches or greater over an area of not less than 30 square feet. The vertical height shall be measured from the top of the ceiling framing members to the underside of the roof framing members.

The rough-framed opening shall be not less than 22 inches by 30 inches and shall be located in a hallway or other location with ready access. Where located in a wall, the opening shall be not less than 22 inches wide by 30 inches high. Where the access is located in a ceiling, minimum unobstructed headroom in the attic space shall be 30 inches at some point above the access measured vertically from the bottom of ceiling framing members. See Section M1305.1.3 for access requirements where mechanical equipment is located in attics.


Very important requirement criteria that many will get wrong! (See BOLD above).

Great graphic as always, Randy. The problem I see is the AHJs enforcing this. I regularly find attics around Portland that have nothing close to the required headroom and often have a furnace crammed inside too. Our tolerance and rule bending goes well beyond homeless people camping for free on the streets.

Jeffrey, does this graphic somewhat make sense?

Honestly, no, the RED box just adds confusion.
Your original graphic is good, but doesn’t accurately portray the 30 inch issue in relation to older homes.
Newer homes don’t generally have an issue with the 30 inch headroom as the hatches tend to be centered in a home (hallway/hall closet/MASTER closet/etc).
Older homes tend to be wherever a contractor/flipper can squeeze one in, typically a bedroom closet and near an exterior wall, so the roof pitch is very low above the access hatch. If the hatch is even large enough for a person to fit, one end may only be as low as 12 inches clearance and the other end maybe 24 inches.
Add in an insulation dam of maybe 10 inches, and it get’s to be a huge PIA attempting to gain access!
Does that help?

I agree there are several situations like you listed that makes attic access a PIA, but IRC 807 doesn’t address those, they just state no obstructions 30” above the attic opening measured from the top of the ceiling drywall. If you have a box extension to clear 16” or more of blown fiberglass insulation there isn’t enough room to get into the attic if have the 30” they require. To be usable you would need 30” above the insulation or box extension whichever is taller. Since nobody is aware of this code and AHJ don’t seem to enforce this I think I will scrap this graphic.

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Shame, as it could be useful, but admittedly, very complex to portray in a simple graphic without endless text to explain everything it needs to contain.
Thanks for the attempt.


@rmayo - Your graphics are next level! Very much appreciated. I tend to file them all to use as needed!