# Separate building? Firewall, Fire Barrier? Occupancy?



## jdhami05 (Jan 24, 2012)

Hello all,

This is my first post on this forum.  I am somewhat confused about a project that I am going to start soon, regarding firewalls, fire barriers, and occupancy classifications.

The project is a gas station located in california.  The jurisdiction uses 2010 california building codes.  The existing store is a 2000 square feet convenience store, occupancy M I believe.  I would like to expand the building with 500 square feet for the same use (M), and 1500 for a auto repair shop (Occupancy S1 I believe), bringing the total to 4000 square feet.  The whole problem is I do not want to separate the building with a firewall because of the location being in a floodplain, thus having to elevate the structure above the base flood elevation, if constructing a new, separate building, by definition.

When I looked at the CBC table 508.4 under Separated occupancies, a M use with a S1 use does not require any hour separation (http://publicecodes.citation.com/st/ca/st/b200v10/st_ca_st_b200v10_5_sec008_par014.htm?bu2=undefined).  Am I correct? Does this mean that no fire barrier between the two uses is required for the expansion?  Also, does a fire barrier separate the building into 2 separate buildings like a firewall?  I just can't get concrete information on this topic on the web.  Some sources interchange the definition of firewall and fire barrier, causing confusion.

In summary, is a fire barrier required for this application.  If so, does it separate the building into 2 separate buildings like a firewall?

Thank You everyone, and sorry for the rookie question.


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## fatboy (Jan 24, 2012)

Welcome to the forum.

No separation required.


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## jdhami05 (Jan 24, 2012)

Thank you very much sir!


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## cda (Jan 24, 2012)

welcome jd

but your local code does not require new additions to meet flood plain condtions?? as in you can keep ading on to this building with no additional requirements??


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## gbhammer (Jan 24, 2012)

Welcome.

It is hard to believe that you would be allowed to add to the footprint of the building if it is nonconforming.


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## jdhami05 (Jan 24, 2012)

Hi cda,

Yes there are still restrictions.  Main one being that you cannot significantly improve a building in a floodplain without having to elevate it to the bfe.  Significant improvement being, any improvement to a building that improves the building more than 50 percent of the existing building's market value.  So, there are still restrictions, and I would have to get a professional appraisal and a quote from a general contractor, with the improvement being no more than 50 percent of the appraisal.

thank you everyone.


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## jdhami05 (Jan 24, 2012)

The biggest problem would have been the firewall.  Any addition in a floodplain would require: “Addition (to an existing structure)” means any walled and roofed expansion to the perimeter of a structure in which the addition is connected by a common load-bearing wall other than a firewall. Any walled and roofed addition, which is connected by a firewall or is separated by independent perimeter load-bearing walls, is new construction.

So, new construction would require the new building to be 6 feet above the existing building, had I had to build a firewall.  This would not at all be practical.  I was really nervous as to what answers I would get on this forum.  But glad all looks good so far as in no firewall requirement for the 2 occupancies.


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## brudgers (Jan 24, 2012)

Hardly a rookie question. It's the sort of thing one hires an architect to answer.


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## jdhami05 (Jan 24, 2012)

Hi Brudgers,

I have an architect on this job.  From what he knows, he has not dealt with this before.  I am sure he can look at the table I referenced and quickly make a determination.  However, I have yet to get a word back from him, thus, having to research everything myself.  Hopefully, he would be more informative next time.

thanks


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## north star (Jan 24, 2012)

*=*

jdhami05,

Welcome to The Building Codes Forum!   

In addition to coming to this fine Forum, have you [ not the architect ] contacted

the AHJ in which this building is located and discussed possibilities with the BO or

Planning Dept. Director?.....Just asking.

*= =*


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## cda (Jan 24, 2012)

JD

a firewall/ barrier does not always make it another building


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## Big Mac (Jan 25, 2012)

Welcome JD

Fire walls / Fire-barrier walls / Fire partitions / Party Walls / Fire Partitions / Smoke Partitions / etc. are all different types of walls with different requirements and different applications.  Having asid that, one wall may be designed to function in multiple capacities.

If you are familiar with the old UBC / Fire walls in the IBC are akin to Area Separation Walls in the UBC

and Fire barrier Walls in the IBC are akin to Occupancy Separation Walls in the UBC

At any rate the current IBC states "Each portion of a building separated by one or more Fire Walls that comply with the provisions of this section shall be considered as separate structures.  Section 706.1.


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