Fire Alarm Notification & Occupancy Separation

[ryant35]

We are designing a fire alarm system in a 5 level, low rise R-2.1 apartment building. The lowest level is below grade parking. The design has notification throughout all common areas and 520HZ low frequency sounders in the sleeping areas. The project is under 2013 CBC & NFPA 72.

During the plan check the reviewer called me to tell me the notification coverage in the lower level parking is not required because of the concrete separation from the R-2.1 occupancy above. I will be confirming with the architect if the construction provides a 4 hour separation between the areas.

We've done home R-2 apartments that had a separate concrete parking structure inside the wood frame building that had a 4 hour separation and did not require notification. We've never seen this come up with on a podium style building like this.

Anyone else ever have this come up?

 

[GoldDigger]

My concern would be that even if there is no flame spread (or even smoke?) from the lower parking level into the residential area, a large fire could cause structural damage that required the evacuation of the residential levels.
Possibly that could wait until first responders were on scene?

 

[ryant35]

My concern would be that even if there is no flame spread (or even smoke?) from the lower parking level into the residential area, a large fire could cause structural damage that required the evacuation of the residential levels.
Possibly that could wait until first responders were on scene?

The lower level is fire sprinkered and monitored by the building fire alarm system, so if there were a fire in the parking level the waterflow switch would activate the fire alarm system and evacuate the building.
The AHJ's comment is regarding providing notification throughout the parking area.