S-1 & S-2 Regarding Parking Garage

[ryan81]

Hello All.

I almost feel silly asking this, but my own personal logic has been stymied many times by the code, so I'll pose the question anyway:

I'm designing a building which includes a personal-use parking garage next to a business occupancy. The garage in question is not accessory to the Business occupancy and will be used to store the business Owner's large RV. Because this garage is over 1,000 SF it falls outside the scope of a "private garage" and is, for code purposes, a "public garage". Section 311.3 Classifies "Parking garages, open or enclosed" as a group S-2 Occupancy. Because the Business Occupancy is a hazard to the S-2 occupancy, a fire barrier wall must be constructed between the two.

With the premise that requirements of the code are minimums. Is there any reason I can't classify the "garage" space as S-1 (which is more restrictive/higher hazard than S-2) to avoid the fire separation between it and the Business Occupancy? My logic is that one ought to be able to store "low-hazard" items in a space purposed for higher-hazard items...a space which is designed to a higher degree of life-safety than would otherwise be required by the code for that low-hazard.

Thanks Everyone!

Ryan

 

[RLGA]

Because the Business Occupancy is a hazard to the S-2 occupancy, a fire barrier wall must be constructed between the two.

Where does it state that? Separation is only required when the separated occupancies method is used. Section 406.6.1 (enclosed garages) refers to Sections 504 and 506 (and 507 if applicable). Sections 504 and 506 both reference Section 508 regarding mixed occupancies. Sections 406.5.3 and 406.5.4 (open garages) reference Section 508.1 directly. If using the nonseparated occupancies method for the entire building you definitely do not need to provide the fire barrier separation.

If you are using separated occupancies and separating the Group B occupancy from the parking garage, you must classify the garage as a Group S-2. Section 406.5.4 (open garages) states specifically that, and Section 311.3 provides a general provision requiring that. Thus, separation is required if you are separating all occupancy groups, and you may be required to separate them if doing a combination of nonseparated and separated occupancies.

 

[mtlogcabin]

How big is the building? You may need to create different fire areas or sprinkle the building. It does not matter if it is an S-1 or S-2 the GVW of the RV will be over 10,000 lbs and that may trigger sprinklers unless your fire area is less than 5,000 sq ft. An S-1 would require a 3-hour wall and S-2 a 2-hour wall.

[F] COMMERCIAL MOTOR VEHICLE. A motor vehicle used to transport passengers or property where the motor vehicle meets one of the following:

1. Has a gross vehicle weight rating of 10,000 pounds (4540 kg) or more.

2. Is designed to transport 16 or more passengers, including the driver.

[F] 903.2.9 Group S-1.
An automatic sprinkler system shall be provided throughout all buildings containing a Group S-1 occupancy where one of the following conditions exists:

4. A Group S-1 fire area used for the storage of commercial motor vehicles where the fire area exceeds 5,000 square feet (464 m2).

[F] 903.2.10 Group S-2 enclosed parking garages.
An automatic sprinkler system shall be provided throughout buildings classified as enclosed parking garages in accordance with Section 406.6 where either of the following conditions exists:

[F] 903.2.10.1 Commercial parking garages.
An automatic sprinkler system shall be provided throughout buildings used for storage of commercial motor vehicles where the fire area exceeds 5,000 square feet (464 m2).

 

[TheCommish]

please give citation for

Because this garage is over 1,000 SF it falls outside the scope of a "private garage" and is, for code purposes, a "public garage".

Thank you

 

[mtlogcabin]

406.3.1 Classification.
Private garages and carports shall be classified as Group U occupancies. Each private garage shall be not greater than 1,000 square feet (93 m2) in area. Multiple private garages are permitted in a building where each private garage is separated from the other private garages by 1-hour fire barriers in accordance with Section 707, or 1-hour horizontal assemblies in accordance with Section 711, or both.

 

[ryan81]

Thanks for your responses everyone. I tried responding end of last week, but the forum must have been down as I could not access the site at all.

Where does it state that? Separation is only required when the separated occupancies method is used. Section 406.6.1 (enclosed garages) refers to Sections 504 and 506 (and 507 if applicable). Sections 504 and 506 both reference Section 508 regarding mixed occupancies. Sections 406.5.3 and 406.5.4 (open garages) reference Section 508.1 directly. If using the nonseparated occupancies method for the entire building you definitely do not need to provide the fire barrier separation.

If you are using separated occupancies and separating the Group B occupancy from the parking garage, you must classify the garage as a Group S-2. Section 406.5.4 (open garages) states specifically that, and Section 311.3 provides a general provision requiring that. Thus, separation is required if you are separating all occupancy groups, and you may be required to separate them if doing a combination of nonseparated and separated occupancies.

Apologies for missing a key piece of information from my original post. I was assuming the use of the separated occupancies method.

I understand that 311.3 lists parking garages (open or enclosed) as S-2. Further, 311.2 states that S-1 occupancies are for storage uses that "are not classified as Group S-2". Perhaps my question to you all is more of a theoretical one. My generic, baseline understanding (right or wrong), is that the code dictates minimum requirements and does not prevent one from going above and beyond what would be minimally required.

Maybe this is overly simplistic - but theoretically speaking, if I had a "container" designed to store an object posing a high fire risk, it stands to reason that i could use that same "container" to store an object posing a lower fire risk. Applying that concept to storage occupancies, S-1 is a higher hazard use than S-2 and is more restrictive from a life-safety design standpoint. From a life-safetly standpoint, what risks of S-1 would prevent storing a (lower hazard) motor vehicle so long as the Special Detailed Requirements in Chapter 4 for Motor-Vehicle-Related-Occupancies (along with other specific provisions of the code for S-1) are met?

Section 903.2.9 cited in mtlogcabin's response (below) seems to open the door to at least the notion that motor vehicles (albeit commercial vehicles in this case) could be stored in an S-1 occupancy even though not specifically included or even implied in section 311.2.

How big is the building? You may need to create different fire areas or sprinkle the building. It does not matter if it is an S-1 or S-2 the GVW of the RV will be over 10,000 lbs and that may trigger sprinklers unless your fire area is less than 5,000 sq ft. An S-1 would require a 3-hour wall and S-2 a 2-hour wall.

[F] COMMERCIAL MOTOR VEHICLE. A motor vehicle used to transport passengers or property where the motor vehicle meets one of the following:

1. Has a gross vehicle weight rating of 10,000 pounds (4540 kg) or more.

2. Is designed to transport 16 or more passengers, including the driver.

[F] 903.2.9 Group S-1.
An automatic sprinkler system shall be provided throughout all buildings containing a Group S-1 occupancy where one of the following conditions exists:

4. A Group S-1 fire area used for the storage of commercial motor vehicles where the fire area exceeds 5,000 square feet (464 m2).

[F] 903.2.10 Group S-2 enclosed parking garages.
An automatic sprinkler system shall be provided throughout buildings classified as enclosed parking garages in accordance with Section 406.6 where either of the following conditions exists:

[F] 903.2.10.1 Commercial parking garages.
An automatic sprinkler system shall be provided throughout buildings used for storage of commercial motor vehicles where the fire area exceeds 5,000 square feet (464 m2).
View attachment 10036

Thank you. I had not yet reached this section of the code when I posted originally. The building in question is approximately 8,800 square feet. The whole building will be sprinkled because there is a single dwelling (R-3) unit attached to the building.

406.3.1 Classification.
Private garages and carports shall be classified as Group U occupancies. Each private garage shall be not greater than 1,000 square feet (93 m2) in area. Multiple private garages are permitted in a building where each private garage is separated from the other private garages by 1-hour fire barriers in accordance with Section 707, or 1-hour horizontal assemblies in accordance with Section 711, or both.

Further - 406.4 reads (in part) "Parking garages, other than private garages, shall be classified as public parking garages..."

Again - Thank you all for your thoughtful responses.