Extra Hazard with Overhead Door

[vinnymac44]

The project I am working on is a extra hazard group 1 occupancy and it includes one 14x14 overhead door. We will need to protect under the door as required.

NFPA 13 2010 edition 8.7.3.1.7 says that "where sidewall standard spray sprinklers are installed to protect areas below overhead doors within ordinary hazard occupancy spaces or rooms, protection area and maximum sprinkler spacing for light hazard as specified in table 8.7.2.2.1 shall be permitted under the overhead doors."

I need some insight on how to approach protecting under the door when it is open. Since 8.7.3.1.7 only references OH and not EH I am kinda stuck on the approach. We would like to stick to sidewalls if possible but I wanted to see if any one else has ran into this or if there is something else in NFPA 13 that I am missing.

 

[cdafd]

Sidewalls are not listed for extra hazard

Is the area under the door extra hazard?

Does not appear there is an out

 

[SprinklerDesigner2]

You are good to go with sidewalls. The sidewalls are spaced per light hazard etc.

8.7.3.1.7 Where sidewall standard spray sprinklers are installed to protect areas below overhead doors within ordinary hazard occupancy spaces or rooms, protection area and maximum sprinkler spacing for light hazard as specified in Table 8.7.2.2.1 shall be permitted under the overhead doors.

Commentary from Handbook:

Sprinkler protection is required under overhead doors so that protection is provided when the doors are open and the ceiling sprinklers are obstructed. In ordinary hazard areas, this provision permits larger doors to be protected by a single sidewall sprinkler, reducing the installation costs while not significantly impacting the protection of the space.

Assume a warehouse with rack storage to 25' protected by an overhead ESFR system.

The way it was explained to me is when the door is up it becomes an Ordinary Hazard area because with the door open it is not possible to have storage piled higher than the door... usually 12' high doors are the max. When the door is closed the overhead ESFR protects the space just in the event there is storage where the door is but that is unlikely.

There is exactly this situation all over the country.