• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

to enclose or not to enclose...a stair

Vlab20

Vlab20

Bronze Member
Joined
Mar 11, 2010
Messages
89
Location
Midwest
Existing 2 story building, unsprinklered. 3100 SF per floor. Floor #1(Tenant A) has a back door and a front door. The front door is connected to a small lobby. Inside that lobby is the stair to the 2nd floor, and a Men's and Women's restrooms. Floor #2 (Tenant B) has a front door that leads to an exterior ADA accessible ramp. Floor #2 also has a stair that leads to Floor #1's front door. The stair is enclosed but is NOT a rated enclosure. Tenant A space is not currently occupied but previously a B-Business occupancy. Tenant B will be a Physical Therapy space and thus a B-Business occupancy. Floor #2 work will be extensive. We will be remodeling the entire 2nd floor.

IEBC 2006 we are Alteration-2

IEBC 2006 Section 703.2.1 Existing vertical openings...all existing interior vertical openings connecting 2 or more floors shall be enclosed with...1-hour assembly.

Exceptions:

1. where vertical opening enclosure is not required by IBC or IFC.

IBC 2009 Section 708.2 Shaft enclosure required.

Exceptions:

7. In other than Groups I-2 and I-3, a shaft enclosure is

not required for a floor opening or an air transfer

opening that complies with the following:

7.1. Does not connect more than two stories.

7.2. Is not part of the required means of egress system.

7.3. Is not concealed within the construction of a

wall or a floor/ceiling assembly.

7.4. Is not open to a corridor in Group I and R occupancies.

7.5. Is not open to a corridor on nonsprinklered

floors in any occupancy.

7.6. Is separated from floor openings and air transfer

openings serving other floors by construction

conforming to required shaft enclosures.

7.7. Is limited to the same smoke compartment.

Question: Do I need to meet all of the 7.1 through 7.7 conditions to utilize this exception? I meet all the exceptions except 7.2

Question: Do I need to enclose the stair in 1-hour rated construction?
 
3100 SF per floor
Click to expand...
Are you sure of the sq ft per floor

AREA, BUILDING. The area included within surrounding exterior walls (or exterior walls and fire walls) exclusive of vent shafts and courts. Areas of the building not provided with surrounding walls shall be included in the building area if such areas are included within the horizontal projection of the roof or floor above.

5. In Group B occupancies, a minimum 30-minute enclosure shall be provided to protect all vertical openings not exceeding three stories. This enclosure, or the enclosure specified in Section 703.2.1, shall not be required in the following locations:

5.1. Buildings not exceeding 3,000 square feet (279 m2) per floor.

5.2. Buildings protected throughout by an approved automatic fire sprinkler system.

It is probably not hard to recalculate and reduce the square footage to less than 3,000 per floor.
 
@mtlogcabin...I might be able to get the calculation down. Not sure if it will be below 3000 SF. Thank you for the "exclusive of vent shafts". I do have a vent shaft that I can subtract and I can be more detailed in my calc at the exterior walls. Hope to see the number below 3000.
 
@mtlogcabin...can any part of the stair be excluded from the SF calculation? The stair is a u-shape with about 12" separation between the stringers. My total SF for the floor is 3010.
 
Just re-read the AREA, BUILDING...I can't exclude any sf from the stair. But it may appear that we will need to add a small shaft and that should take us close to 3000 sf.
 
You must log in or register to reply here.
Top