Open Corridors in Highrise Required to be Rated?

9/7/2022

We are working on a 20-story apartment building where the corridors are open with parapet walls on either side. These serve as an exit access corridor. The project is under NFPA 101.

In Chapter 7 of NFPA 101, the exist access corridor is supposed to have a minimum fire resistance rating of 1-hour. However, I can't seem to find any provision in the code regarding open corridors.

Will these corridors be required to have a fire resistance rating? What about the doors of the dwelling units?

I'm assuming if the corridor is not fire rated, then we wouldn't need opening protection through these partitions/walls.

Thanks in advance.

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11 Comments

chad

9/7/2022 06:49:10 am

The corridors are open to an atrium, is that what you mean?

Unit doors are certainly going to be required to be rated.

Alex

9/7/2022 07:48:58 am

Hi,

Few questions before I can really answer your question:
- Is the open corridor around the perimeter of the building? Or, is it open to an atrium?
- What is the buildings construction type?

Either way, the unit walls should be rated with rated doors/frames.

Thanks,
Alex

9/7/2022 08:12:22 am

7.5.3 Exterior Ways of Exit Access

7.5.3.1

Exit access shall be permitted to be by means of any exterior balcony, porch, gallery, or roof that conforms to the requirements of this chapter.

7.5.3.2

The long side of the balcony, porch, gallery, or similar space shall be at least 50 percent open and shall be arranged to restrict the accumulation of smoke.

7.5.3.3

Exterior exit access balconies shall be separated from the interior of the building by walls and opening protectives as required for corridors, unless the exterior exit access balcony is served by at least two remote stairs that can be accessed without any occupant traveling past an unprotected opening to reach one of the stairs, or unless dead ends on the exterior exit access do not exceed 20 ft (6100 mm).

7.5.3.4

Exterior exit access shall be arranged so that there are no dead ends in excess of those permitted for dead-end corridors in Chapters 11 through 43.

edward Ferraioli

9/7/2022 08:26:21 am

Im in nj code. Full sprinkler building corridors are rated 30 minutes 20 minute fire door. Not sorinklered 1 hour. Open to atrium what ever attruim rating is. If open to atrium the atrium smoke control must be able to handle corridors also in there smoke test.

Ed James Ferraioli

9/7/2022 08:29:58 am

Look in IBC 2018 section 1020 I'm using nj edition it also in international IBC around same section

Todd E Wyatt

9/7/2022 08:30:25 am

NFPA 101 Life Safety Code is organized by general chapters (1-11, 43) and chapters (12-42) based on Occupancy Classifications (OC). Chapter 11 Special Structures and High-Rise Buildings includes requirements for “high-rise buildings” (HRB).

Based on your reference to “apartment”, we will assume that the OC is “New Apartment Buildings” and shall meet the requirements of Chapter 30.

30.3.6 Corridors.
30.3.6.1 Walls.
Exit access corridor walls shall comply with 30.3.6.1.1 or 30.3.6.1.2.
30.3.6.1.1
In buildings not complying with 30.3.6.1.2, exit access corridor walls shall consist of fire barriers in accordance with Section 8.3 that have not less than a 1-hour fire resistance rating.
30.3.6.1.2
In buildings protected throughout by an approved, supervised automatic sprinkler system in accordance with 30.3.5.1.1, corridor walls shall have a minimum 1⁄2-hour fire resistance rating.

Since high-rise buildings (HRB) are required to be protected by an automatic sprinkler system (ASPS), the Exit Access Corridors (EAC) are required to have a “minimum 1⁄2-hour fire resistance rating.” Doors that “open onto exit access corridors shall have not less than a 20-minute fire protection” and shall be “self-closing and self-latching.” The 0.5-Hour EAC walls are required to be Fire Barriers meeting 8.3. In addition to the fire-resistive rated (FRR) EAC walls, “dwelling units shall be separated from each other by walls and floors constructed as fire barriers having a minimum 1⁄2-hour fire resistance rating.”

The use of the term “parapet” references exterior walls partially or entirely above the roof line.

Jamal

9/7/2022 08:34:37 am

Open Areas corridor/ Door / Walls NOT required to be Fire Rated Material . The Material selection shall be Flame spread index 0- 25 since high rise , whereas the material of cement and bricks comes under 0-25 FSI . Solid Block Bricks are automatically 2 Fire Rated .
You may refer to NFPA220 as well .
Further the main important is that building approved by AHJ under construction type refer to NFPA 5000 so accordingly you must comply the building as per Approved Building code and Life .

Moreover you share the full details then possible FRA can be done .

Jesse

9/7/2022 08:37:48 am

Are these open corridors open to an atrium? Or are they open to atmosphere? If open to atmosphere, I wouldn't think the fire rating requirement to apply.

schulman

9/7/2022 08:46:56 am

i cannot think of a single instance of what you described, regardless of atrium, etc.., where the penetrations would not be required to be rated.

Glenn Berger

9/7/2022 08:52:12 am

What I interpret in your question is that you really do not have exit corridors or exit access corridors as defined by NFPA 101. You have aisleways that lead to an exit (stairway). The walls of the dwelling units need to be rated.

Tim

9/8/2022 12:41:12 am

The separating walls between units must be fire rated 60 minutes. The passages if open and ventilated will not pose a problem provided you have the option to travel in two directions to a protected stair.

We have done a CFD model on similar design an the fire did not spread past unit of fire origin and passages remained usable with tolerable conditions.

Escape in two directions mitigate possible intolerable conditions on passage passing unit on fire.

Materials used for construction must be considered as well.

Open Corridors in Highrise Required to be Rated?

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