Sprinkler Requirement for S-2 open garage under R-2 Apartments

[J. Mulholland]

2015 IBC - Is there a code section that allows R-2 occupancy over S-2 open parking garage where the garage is NOT sprinklered? 2015 IBC does not require open parking S-2 occupancies to be sprinklered, however Section 510.2 does require an occupancy below the horizontal building separation to be sprinklered. Section 510.4 allows S-2 open garage below R-2 but doesn't list a sprinkler requirement. We have a small amenity space at grade among the open parking area but this could be classified as "accessory" use because it's small. Can I use Section 510.4 and not sprinkler the S-2 open garage area?

 

[classicT]

510.2 Horizontal Building Separation Allowance
A building shall be considered as separate and distinct buildings for the purpose of determining area limitations, continuity of fire walls, limitation of number of stories and type of construction where all of the following conditions are met:

1. The buildings are separated with a horizontal assembly having a fire-resistance rating of not less than 3 hours where vertical offsets are provided as part of a horizontal assembly, the vertical offset and the structure supporting the vertical offset shall have a fire-resistance rating of not less than 3 hours.
2. The building below the horizontal assembly is of Type IA construction.
3. Shaft, stairway, ramp and escalator enclosures through the horizontal assembly shall have not less than a 2-hour fire-resistance rating with opening protectives in accordance with Section 716.0
   
   Exception: Where the enclosure walls below the horizontal assembly have not less than a 3-hour fire-resistance rating with opening protectives in accordance with Section 716, the enclosure walls extending above the horizontal assembly shall be permitted to have a 1-hour fire-resistance rating, provided:
   
   1. The building above the horizontal assembly is not required to be of Type I construction;
   2. The enclosure connects fewer than four stories; and
   3. The enclosure opening protectives above the horizontal assembly have a fire protection rating of not less than 1 hour.
   4. Interior exit stairways located within the Type IA building are permitted to be of combustible materials where both of the following requirements are met:
      4.1. The building above the Type IA building is of Type III, IV, or V construction.
      4.2. The stairway located in the Type IA building is enclosed by 3-hour fire-resistance-rated construction with opening protectives in accordance with Section 716.
4. The building or buildings above the horizontal assembly shall be permitted to have multiple Group A occupancy uses, each with an occupant load of less than 300, or Group B, Group I-1, Condition 2 licensed care facilities, M, R, or S occupancies.
5. The building below the horizontal assembly shall be protected throughout by an approved automatic sprinkler system in accordance with Section 903.3.1.1, and shall be permitted to be any occupancy allowed by this code except Group H.
6. The maximum building height in feet (mm) shall not exceed the limits set forth in Section 504.3 for the building having the smaller allowable height as measured from the grade plane. Group I-1, Condition 2 licensed care facilities shall be permitted to use the values for maximum height in feet for Group R-2 occupancies.

510.4 Parking Beneath Group R
Where a maximum one story above grade plane Group S-2 parking garage, enclosed or open, or combination thereof, of Type I construction or open of Type IV construction, with grade entrance, is provided under a building of Group R, the number of stories to be used in determining the minimum type of construction shall be measured from the floor above such a parking area. The floor assembly between the parking garage and the Group R above shall comply with the type of construction required for the parking garage and shall also provide a fire-resistance rating not less than the mixed occupancy separation required in Section 508.4.

 

[RLGA]

Section 510.4 does not provide a horizontal separation between the Group S-2 parking garage and the Group R-2 apartments above. Since Buildings with a Group R occupancy are required to be sprinklered throughout, the Group S-2 below is also required to be sprinklered.

 

[classicT]

Posted the code in question in a preceding post just for ease of access to all.

If using podium construction, then condition #5 of Section 510.2 is pretty definitive. "The building below the horizontal assembly shall be protected throughout by an approved automatic sprinkler system." Not much wiggle room there.

So if not using podium construction, you could go with Section 510.4; however that is limited to construction of Type I or Type IV. You could then proposed mixed use separated; however, given the R-2 use and fact that all Group R have to be sprinkled, there is not an out from sprinklers within that path either.

So, sprinklers it is, as far as I can decipher.

 

[classicT]

Section 510.4 does not provide a horizontal separation between the Group S-2 parking garage and the Group R-2 apartments above. Since Buildings with a Group R occupancy are required to be sprinklered throughout, the Group S-2 below is also required to be sprinklered.

Damn Ron... ya cut me off and beat me to the punch while I was still typing my follow up post to the code sections I posted.

Glad we are on the same page though!