Existing Corridor at Tenant Improvement

[ETThompson]

Hi

We're doing a tenant improvement for a hair/beauty salon in an existing 1-story shell. The project is at grade and all exits lead to the exterior and a public way. The overall space is Business / B use except for a small accessory storage S-2 space. Construction Type is IIB. Overall space is about 11k sf. The project is not sprinkelered. We're under the Ohio Building Code 2017 which follows the 2015 IBC.

The existing build-out (which we're partly keeping), has what appears to be an existing 1-hr corridor. However, our analysis is that because we have (3) exits and all our travel paths are well under our required travel distances (200' feet allowed, our maximum is 115 ft.).

Thus our analysis is that this former "corridor" is not required to be a corridor for our project. (Corridor defined in Ch. 2 as "An enclosed exit access component that defines and provides a path of egress travel"). Are we correct in thinking this is not required to be considered a rated corridor?

The design proposes a couple of large unprotected openings in this former rated corridor (8' long by 6' high interior relight glazing, not fire rated). Our thought is since the corridor is not truly required to be a "corridor", we should be allowed to have these unprotected openings (also, non-rated doors, etc).

I should also mention that this project has been permitted, without adverse comment on the issue above. The concern on a team member's part is the field inspector will raise an objection, and we'd like to confirm that our analysis is correct.

See attached Life Safety plan showing corridor (hm, having trouble attaching file...will do later...). This drawing probably should have been clearer that the existing 1-hr rated corridor was not required for our design, but as I said it was successfully permitted this way...

Thanks

 

[RLGA]

If the occupant load is greater than 30 (and I think it is), then the corridor is required to have a 1-hour rating per Table 1020.1 using fire partitions with 20-minute doors and 3/4-hour windows, sidelights, and transoms.

 

[steveray]

What part of the IEBC are you using? 2012 IEBC commentary for prescriptive compliance...

Alterations are to conform to
the requirements for a new structure. For example,
consider the corridor of an office building that is to be
extended 18 feet (5486 mm), as shown in Commentary
Figure 403.1. The existing office building has no
sprinkler system (and none is proposed), so the corridor
extension walls and doors are to be fire-resistance
rated in accordance with Section 1018 of the
IBC. This is applicable even if, for some reason, the
walls and doors of the existing corridor system are
not fire-resistance-rated construction.

 

[ETThompson]

If the occupant load is greater than 30 (and I think it is), then the corridor is required to have a 1-hour rating per Table 1020.1 using fire partitions with 20-minute doors and 3/4-hour windows, sidelights, and transoms.

I understand, and that is what we were debating here, but what triggers this space being considered a "corridor" from the point of view of the code? Is any long, skinny space used for circulation automatically considered a "corridor" (and thus if the occ load is over those limits, must be rated)? Or does it have to be "needed" to make the exiting work? In our case, we can get entirely out of the building within the required travel distances, so it just seems like the "corridor" shouldn't be required. If there was no existing hall/corridor and we could just get out under 200', we wouldn't be required to introduce a rated element, right? I thought travel distance was how far you're allowed to go as part of the Exit Access, and doesn't have to be protected.

 

[ETThompson]

PS - the occupant load in the exist corridor would be more than 30.

 

[ETThompson]

We hadn't really been using the IEBC or Ch. 34, though maybe we should. I guess I'd looked at it just like a tenant improvement (though as with the "corridor" we are keeping parts of the existing interior fit-out). I don't believe Ohio has adopted the IEBC, but since we're following the current code for the new build (and mostly for the existing condition), I think we conform to the spirit of the section you posted, since we're looking at this as if it were under the new construction code.

 

[RLGA]

An exit access component is anything that isn’t considered an exit or an exit discharge component. A corridor is considered part of the exit access, and as we’ve shown it may be required to be protected under certain conditions. If a space is used primarily for circulation and is defined by walls, then it will be considered a corridor (you know, if it looks like a duck...).

Ohio does not use the IEBC, but has reinserted requirements into Chapter 34 that was unused in the 2015 IBC. Section 3404.1 on alterations indicates that all alteration work must comply with the requirements for new construction and the building cannot be made any less complying with the building code than it was prior to the alteration. Thus, if the existing corridor was 1-hour construction, then it must remain 1-hour construction, unless you did something that altered the application of the building code, such as adding a sprinkler system.

 

[ETThompson]

OK, that makes sense even if not the answer we wanted... now we'll have to decide if we bring it up or just see if the inspector calls us on it... as I said, got through permit with no adverse comment...

 

[ETThompson]

I am curious as to what the *reason* for rating the corridor is...again it seems like if the corridor weren't there, and you could get to the exit from the building within the travel distance, you wouldn't be in a rated (protected) condition...so why does the corridor have to be more protected than just, say, an open space...? Just curious.

 

[Tim Mailloux]

OK, that makes sense even if not the answer we wanted... now we'll have to decide if we bring it up or just see if the inspector calls us on it... as I said, got through permit with no adverse comment...

If someone dies and get injured in a fire its not the AHJ that's going to get sued....Can you guess who the lawyers will go after?

 

[my250r11]

FWIW, just because it was missed in plan review doesn't mean you don't still have to build it to code. It usually is cheaper to do it correct than wait till is caught at later date and have to demo and redo correctly, but hey what do I know, I see it done the later way all the time. JMHO.

 

[RLGA]

I am curious as to what the *reason* for rating the corridor is...again it seems like if the corridor weren't there, and you could get to the exit from the building within the travel distance, you wouldn't be in a rated (protected) condition...so why does the corridor have to be more protected than just, say, an open space...? Just curious.

Corridors are not subject to the limitations of intervening rooms per IBC Section 1016.1, but they do have their own requirements. Corridors must lead to an exit (Section 1020.6), so, once in a corridor, the occupant is given a defined route to an exit and a certain level of protection (either a sprinkler system or fire-rated assemblies). To egress through an intervening room, the rooms must be accessory to one another. You could have a large open office with smaller private offices egressing through the open office to the exits, provided the maximum travel distance is not exceeded to at least one of the exits. However, if the open office then egresses through a storage room, a factory shop, another leased office space, or any other space not accessory to the open office area to reach one or more required exits, then a corridor must be used.

 

[JPohling]

Construct it to code not to what the plan checker obviously missed. Especially now that you know that it is a faulty design and that knowledge resides on the internet.
If something goes wrong they will be coming after you.

 

[steveray]

CORRIDOR. An enclosed exit access component that defines and provides a path of egress travel.

When in doubt go to the definitions....

 

[ETThompson]

I didn't mean to be cavalier, and this is for a colleague's project so I don't have direct control. I'll advise the team however that they should correct this condition.

I will say, it is really easy to exit this space in multiple ways, and rating the openings (remember, corridor itself is already rated) would have a minimal effect in my opinion. But the code is the code...