Determining Fire Area in Non-Separated Mixed Occupancies.

[Seanior]

I searched this forum feverishly before making this my first time post. I have a mixed occupancy building that requires no separation. B, M, and S-1 Occupancies (its a car dealership) Could someone clarify where my fire areas begin and end? Is it between occupancy classifications or is it the nearest fire barrier / exterior wall? I seem to only find smoke when looking for said FIRE AREA and would appreciate any help.

Common sense tells me that fire area would extend to the fire barriers, but since none of my occupancies exceed the sprinkler requirements for maximum fire area, but combining them would do so with no separation... I'd like another opinion.

Thank you in advance!

Seanior!

 

[steveray]

FIRE AREA. The aggregate floor area enclosed and bounded by fire walls, fire barriers, exterior walls or horizontal assemblies of a building. Areas of the building not provided with surrounding walls shall be included in the fire area if such areas are included within the horizontal projection of the roof or floor next above. [F]

And welcome to the forum!

 

[steveray]

You may have to separate to not have to sprinkler.....Height and area is one reason to sprinkler, Chapter 9 fire suppression has a bunch more....and fire barriers create separate fire areas which may provide some relief from sprinkler requirements.

 

[cda]

Welcome welcome

 

[cda]

From RGLA

http://www.specsandcodes.com/articles/the%20code%20corner%20no.%2027%20-%20fire%20areas.pdf

 

[Seanior]

Thanks! and Thank you for the Great Welcome! This is going to prove to be a great resource!

 

[cda]

Thanks! and Thank you for the Great Welcome! This is going to prove to be a great resource!

Keep on coming and also ad time

Forum is supported by members you can become a full blown "sawhorse"

http://www.thebuildingcodeforum.com/...free-book.html

And the millions of benefits ::::

http://www.thebuildingcodeforum.com/...ed-member.html

 

[RLGA]

With no fire barriers, the entire building would be considered a single fire area of multiple occupancy groups: one Group M fire area, one Group B fire area, and one Group S-1 fire area, each having the area of the entire building. If the area exceeds the threshold for a sprinkler system, then a fire barrier or barriers will be needed to ensure that no occupancy group is within a fire area that exceeds the maximum area for that occupancy group to avoid a sprinkler system.

Please note, the IBC has changed since I wrote the article mentioned in the post above. Fire barriers used for occupancy separation may not necessarily qualify for use in determining fire areas. In the 2009 IBC, the fire barriers between fire areas of mixed occupancies cannot be less than the highest rating indicated in Table 707.3.9 (707.3.10 in the 2012 IBC) for the occupancies under consideration. For example, your Group S-1 would require a 3-hour fire barrier between it and the Groups B and M (which only require a 2-hour fire barrier, but the Group S-1 has the higher value).

 

[Seanior]

FANTASTIC INFORMATION! I ended up determining exactly what you stated. Thanks again!

 

[JBI]

Without separations you would need to base the allowable 'fire area' in accordance with the most restrictive use in the building. Separations would allow use of the 'sum of the ratios' method in Chapter 5.

 

[RLGA]

Without separations you would need to base the allowable 'fire area' in accordance with the most restrictive use in the building. Separations would allow use of the 'sum of the ratios' method in Chapter 5.

For all intents and purposes, occupancies that are not required to be separated per Table 508.4 are still considered separated. In this case, none of the occupancies require separation (Groups B, M, and S-1), so they have the option of using either the nonseparated or separated method.