Vertical access can be a fixed internal stair ramp or exterior stair.
Irc attic access requirements.
When the access is located in a ceiling minimum unobstructed headroom in the attic space shall be 30 inches 762 mm at some point above the access measured vertically from the bottom of ceiling framing members.
The following are the requirements taken directly from the irc.
This section makes it very clear.
The rough framed opening shall not be less than 22 inches.
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.
Habitable attics require a vertical access and emergency escape and rescue opening.
Attic area exceeds 30 square feet and minimum vertical height of 30 inches measured from the top of the ceiling framing members to the bottom of the roof.
Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow.
See section m1305 1 3 for access requirements where mechanical equipment is located in attics.
Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that exceed 30 square feet 2 8m squared and have a vertical height of 30 inches 762 mm or more.
The rough framed opening of the attic access shall be not less than 22 inches by 30 inches 559 mm by 762 mm for you canucks.
2006 irc residential construction.
The rough framed opening.
Attic access requirements after getting help from an internachi inspector we ve come up with irc 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 762 mm or greater over an area of not less than 30 square feet 2 8 m 2.
Roof construction an attic access opening shall be provided to attic areas that exceed 30 square feet 2 8m2 and have a verti cal height of 30 inches 762 mm or greater.
2009 ibc commercial construction requirement for attic space access 1209 2 attic spaces.