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Access to attic space from another attic

emcreech

Member
Joined
Aug 14, 2013
Messages
5
Location
Raleigh, NC
I'm a Newbie here and apologize if there was an existing thread where I should have tacked this. I've found gobs of info here and elsewhere on Web re: attic access, but not this. Is there a difference if the opening is from another attic through the sheathing or extension of roofing OSB? (Latter case applies to space over large dormer window.)

Case in point: We added a 2-story attached garage, completed in Nov 2012. The only access to new attic is through a 14" x 22" (W x H) opening cut through the sheathing of the original end wall of the house from the existing attic. Access to existing attic is not a problem. It would not be possible to make opening significantly larger without structural changes. (There are actually 2 trapezoidal openings with post (2 - 2x4's) between. 14" x 22" is the larger one.)

The new attic space is >30 sq. ft. & taller than 30"*. If a thin, acrobatic 5' person could get in there, he could stand in the middle. It would be possible to use it for storage if assessable, but with all the knee-wall space, I do not see how even a committed pack-rat could need it. All that is up there is a lot of NM wire, boxes for 2 ceiling fixtures, and drops for 3 outdoor floods & 5 knee-wall lights.

I have painstakingly run telephone & Cat5 cable across the corner and into knee-wall space. (I stupidly didn't think to do that during construction.) I want to add another outdoor LED flood on opposite end of house, but on same circuit. Only reasonable place to tie-in is in that new attic. I'm sure there will be other reasons to get up there.

*Is that 30 sq ft having 30" above or total area of attic having at least 30" height in the center? Space in question would meet both conditions, but not space over dormer.

Thank you for being here and any advice you can give me.

EM Creech
 
First, Welcome emcreech! Glad you found us and jumped in!

No, nothing prohibits you from accessing an attic via another attic as long as the opening meets the minimum dimensions for an attic access. Unamended IRC code is 22 X 30.
 
Yankee said:
Would be fine here.
I do not understand your reply, Mr. Yankee. Do you mean that where you live the 14 x 22" opening between attics would meet requirements for access to the new space?
 
Thank you! Mainly wanted to be sure I was not missing some exception. I'll probably contact the builder and see what gives.

I also asked about the determining factor for access. Is it min. of 30 sq ft which has 30" above it all, or is it the total area of an attic having at least 30" height in the center? Space in question would meet both conditions, but not space over dormer.

Wish I'd come here during construction last year.
 
fatboy said:
First, Welcome emcreech! Glad you found us and jumped in!No, nothing prohibits you from accessing an attic via another attic as long as the opening meets the minimum dimensions for an attic access. Unamended IRC code is 22 X 30.
My reply (#6, now maybe #7) was intended for Fatboy. I must not have clicked the right "Reply" button.
 
SECTION R807 ATTIC ACCESS

R807.1 Attic access. Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that exceed 30 square feet (2.8 m2) and have a vertical height of 30 inches (762 mm) or greater. 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 not be less than 22 inches by 30 inches (559 mm by 762 mm) and shall be located in a hallway or other readily accessible location. When located in a wall, the opening shall be a minimum of 22 inches wide by 30 inches high. 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. See Section M1305.1.3 for access requirements where mechanical equipment is located in attics.
 
@ emcreech..........When you hit reply, it just falls in the order. If you want to reply to a specific post, stay on that one, and hit the "reply with quote" button at the bottom right hand side of the post. Or, copy/paste the post you are replying to.
 
Last edited by a moderator:
cda said:
SECTION R807 ATTIC ACCESS R807.1 Attic access. Buildings with combustible ceiling or roof construction shall have an attic access opening to attic areas that exceed 30 square feet (2.8 m2) and have a vertical height of 30 inches (762 mm) or greater. 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 not be less than 22 inches by 30 inches (559 mm by 762 mm) and shall be located in a hallway or other readily accessible location. When located in a wall, the opening shall be a minimum of 22 inches wide by 30 inches high. 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. See Section M1305.1.3 for access requirements where mechanical equipment is located in attics.
Thanks, CDA. <> is what I was missing from everywhere else I had looked.
 
emcreech said:
Thanks, CDA. <> is what I was missing from everywhere else I had looked.
The code cannot address every situation that can come up

Are you kind of wanting the builder to give you a code compliant attic access?

Was this work done in an area that has adopted the Irc??
 
Picture this: A code compliant attic access panel 22x30 to an attic space with nothing but trusses. Access to the attic is compliant through the 22x30 opening but access throughout the attic is limited by the spacing and configuration of the trusses which are 16" on center. There would be no way to access any part of the attic in a code compliant manner if the access provisions of the code applied. I think the code requirement is to gain access to the space, then there are provisions for access to any equipment if installed. The access requirement can't possibly apply to every possible path. So if the dormer area in question did not have sheathing and consisted of open trusses it would be compliant, you would still need to fit between the framing just as you would elsewhere. IMO the opening cut in the sheathing would neet to be cut as wide as the truss spacing (14 1/2") and 30 tall and it would be fine as long as there was no equipment to access. I don't see how cutting the sheathing back to 22" but leaving the truss member would make any difference or would be any different than the rest of the attic. Maybe this kind of fits your conditions?
 
I would suggest that you get everything done that you plan on doing while you are still young and thin enough to fit through the opening...and leave it alone.

Fatboy will tell you 22"x30" because ...well he is a fatboy
 
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