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Fire Separation in unlimited area building

M

mwskopf

SAWHORSE
Joined
Sep 30, 2019
Messages
60
Location
Kansas
Hello All.
I have a question regarding an unlimited area F-2 factory with small office.
Would a Business occupancy appendage be allowed to be connected to unlimited area F-2 factory with a 2hr fire barrier separation per table 508.4? The business office is bigger than accessory use rules.
There would be a 60' yard around the whole "complex".
2018 IBC
Type IIB buildings
See attached crude sketch.
Thanks
 

Attachments

Can you classify the B as accessory?

2021 IBC 507.1.1 Accessory Occupancies​

Accessory occupancies shall be permitted in unlimited area buildings in accordance with the provisions of Section 508.2, otherwise the requirements of Sections 507.3 through 507.13 shall be applied, where applicable.
 
Sorry, reread the OP, and you answered already that accessory is not an option.

Which unlimited area option are you using from Sec. 507?
 
See if this code path will work

508.3 Nonseparated occupancies.
Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

508.3.1 Occupancy classification.
Nonseparated occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space. In addition, the most restrictive provisions of Chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area.

508.3.2 Allowable building area, height and number of stories.
The allowable building area, height and number of stories of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration for the type of construction of the building in accordance with Section 503.1.

506.2.2 Mixed-occupancy, one-story buildings.
The allowable area of a mixed-occupancy building with no more than one story above grade plane shall be determined in accordance with the applicable provisions of Section 508.1 based on Equation 5-1 for each applicable occupancy.


1695770141738.png
 
mtlogcabin said:
See if this code path will work

508.3 Nonseparated occupancies.
Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

508.3.1 Occupancy classification.
Nonseparated occupancies shall be individually classified in accordance with Section 302.1. The requirements of this code shall apply to each portion of the building based on the occupancy classification of that space. In addition, the most restrictive provisions of Chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area.

508.3.2 Allowable building area, height and number of stories.
The allowable building area, height and number of stories of the building or portion thereof shall be based on the most restrictive allowances for the occupancy groups under consideration for the type of construction of the building in accordance with Section 503.1.

506.2.2 Mixed-occupancy, one-story buildings.
The allowable area of a mixed-occupancy building with no more than one story above grade plane shall be determined in accordance with the applicable provisions of Section 508.1 based on Equation 5-1 for each applicable occupancy.


View attachment 11553
Click to expand...
You are suggesting to not use an unlimited area building provision, correct?
 
The answer to your question is yes; what your propose would be an unlimited area, non-sprinklered F2 primary use with a separated B mixed used.
As others suggest there may be alternative code paths you could explore to see if they offer a more budget-friendly approach. I.e if you look into the non-separated mixed use path, 508.3, you find that in order to comply without the need for the 2 hour fire barrier between the office and factory, you need to look at each area of the code and apply requirements based on whichever applicable use (F2 or B) is more restrictive. In most cases one looks up chapter 9 sprinkler requirements for the non-separated uses and see if either are required sprinklers (likely not for your B use, and not for your F2 use), fire alarms, and so on, but there are other code requirements throughout you need to go through and consider.
One thing you need to closely watch with this approach is to be sure you do not have any other use classifications within the office space or F2 space that could create new headaches when taking the non-separated use approach (this is true for accessory uses too if it was the case): if for example you have a break room for the employees, you then have a space that should be classified as A2. chapter 9 establishes that A2 fire areas exceeding 5000 SF are required to have sprinklers Installed throughout the entire floor. Regardless of the code path you choose for designating the A2 area as accessory, separated, or non-separated, you’ll find it will be necessary to separate the A2 area with a 2 hour fire barrier in order to not need to sprinkler the entire floor (building in your example). Without the fire barrier compartmentalization the A2 fire area, that relatively small A2 space causes the entire floor (building) to be classified as an A2 fire area.
Another tip I’ll put out there is you can use a combination of approaches when deciding between designating different use classifications as separated, bin-separated, or accessory uses. This is helpful when you identify many different use classifications in your building but only a few create additional code restrictions if not separated.
Finally, section 311.1.1 is a useful section of the code that can help you avoid needing to classify storage areas as either S1 or S2; so long as the space is an accessory to the main use (purpose) of the building, the space is to be assigned the same use classification as the primary use. Take note that the term accessory in this case is not the same as accessory use: this provision is not restricted by the 10% rule.
I know I went off topic here, but I have always found it necessary to look at all of these items together when planning the best code path. code planning is much easier when you can include sprinklers, without them there are many pitfalls along the way.
 
All, Thanks for the replies!
I hadn't thought about the mixed non-separated as I didn't think it would allow enough square footage, but it may be applicable with both B and F-2 being 23,000 allowable Per 506.2 table non-sprinkled. With a frontage increase, that would be more than enough. (for this phase anyway, they are growing quickly). I try to encourage most all of our clients to sprinkle, but it is a significant investment at about 5-7 bucks a foot around central KS area (new construction)
MadrkTEK you make some good points about being careful with the non-separated aspect. ( and the 311.1.1 tip!)
The office will indeed have a break room but will be small and I believe will fall under the "small assembly" classified as B rule in 303.1.2.
Thanks again Gents and ladies if any.
 
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