Existing unrated corridor

[sergoodo]

My interpretation of the 2012 IBC is the corridor can remain unrated. Somebody has to disagree, maybe....and hopefully not everybody. School me - Thanks

 

[mtlogcabin]

Existing?

So is it a remodel, change of use. Why do you think the corridor needs to be rated now?

 

[cda]

Fire sprinkler system in building??

 

[cda]

Guess my only question is how the occupant load was figured

Are the 27 their own group or will be in the rest of the office

 

[sergoodo]

Guess my only question is how the occupant load was figuredAre the 27 their own group or will be in the rest of the office

Gross Sf / 100 occupants to to determine # of exits required, then checked the placement. Then calculated to load served by unrated corridor. The building is unsprinkled and the 27 is waiting room occupancy. Since < 49 and direct safe exit at level of discharge...no reason to upgrade the corridor and run'em through the building to a 2nd exit.

 

[sergoodo]

Existing?So is it a remodel, change of use. Why do you think the corridor needs to be rated now?

I interpret rating is not required, no better place to test interpretation...check with the internets before I open my mouth.

 

[cda]

Gross Sf / 100 occupants to to determine # of exits required, then checked the placement. Then calculated to load served by unrated corridor. The building is unsprinkled and the 27 is waiting room occupancy. Since < 49 and direct safe exit at level of discharge...no reason to upgrade the corridor and run'em through the building to a 2nd exit.

Sounds good, launch it

 

[JBI]

Corridors are components of exit access and are often, though not always, permitted to be unrated.

For an existing corridor that is a lawfully existing building element, if it was compliant the day it was built it can remain 'as is' until something (work on/in the building) requires otherwise.

 

[mtlogcabin]

I agree with JBI with regards the corridor rating.

I disagree with your exit plan. Half of the assembly room should be accounted for in the corridor and only 8 should be counted as exiting through the assembly room. Roughly a gain of 6 in the corridor. Now you should be taking half of the 19 through the assembly room exit also for the correct numbers serving each exit. Doing it this way the corridor serves an occupant load of 25 which is still below today's code requirements for rating the corridor.

 

[steveray]

Doesn't 7+7+6= 20? And the mech room and corridor are covered by that?

 

[sergoodo]

Doesn't 7+7+6= 20? And the mech room and corridor are covered by that?

Yikes, I was going to change a 1 occupant blue to green...got distracted after initial initial thought and typing 19.

Maybe they make a pill for that type of error.

 

[sergoodo]

Thanks for all the insight. Mucho thanks

 

[JBI]

And lest we forget, the 'assembly' space with an occupant load below 50 is not regulated as an 'A' occupancy, but as a 'B'... Occupant load gets calculated by 'use of space', but exit requirements are based on Occupancy Group. (that actually simplifies things BW)