Sprinkler ommission for exterior corridor

[Inspector 102]

A building has an exterior corridor between 2 buildings to an entry door. The owner would like to put a roof assembly over this for weather protection (rain and snow). Both sides of the corridor are cement block and brick construction. Both buildings are fully sprinklered. The roof assembly they have proposed will be PT lumber stringers and purlins with a standing seam metal roof membrane.

I seem to remember that there are provisions for sprinkler omissions where these area are not used for storage. Since this is simply an entrance "corridor", I think this might be acceptable. Otherwise there will need to be a dry pipe sprinkler installed due to the exterior location and the winter environment here.

Is there an exception based on material or size that would be applicable for this type of situation. Thank you.

 

[cda]

just roof only???

no sides???

what edition of NFPA 13 are you under?

In away if the two buildings are connected, you kind of have one building

 

[steveray]

With walls and a roof it is not "exterior" anymore....Roof may not be able to be wood, may need to be considered one building or firewall constructed.

 

[cda]

from NFPA 13 2013 edition same in the 2010

Look at ::: 8.15.7.4

8.15.7* Exterior Projections.

8.15.7.1 Unless the requirements of 8.15.7.2, 8.15.7.3, or 8.15.7.4 are met, sprinklers shall be installed under exterior projections exceeding 4 ft (1.2 m) in width.

8.15.7.2* Sprinklers shall be permitted to be omitted where the exterior projections are constructed with materials that are noncombustible, limited-combustible, or fire retardant–treated wood as defined in NFPA 703.

8.15.7.3 Sprinklers shall be permitted to be omitted from below the exterior projections of combustible construction, provided the exposed finish material on the exterior projections are noncombustible, limited-combustible, or fire retardant–treated wood as defined in NFPA 703, and the exterior projections contain only sprinklered concealed spaces or any of the following unsprinklered combustible concealed spaces:

(1)

Combustible concealed spaces filled entirely with noncombustible insulation

(2)

Light or ordinary hazard occupancies where noncombustible or limited-combustible ceilings are directly attached to the bottom of solid wood joists so as to create enclosed joist spaces 160 ft3 (4.5 m3) or less in volume, including space below insulation that is laid directly on top or within the ceiling joists in an otherwise sprinklered attic [see 11.2.3.1.4(4)(d)]

(3)

Concealed spaces over isolated small exterior projections not exceeding 55 ft2 (5.1 m2) in area

8.15.7.4 Sprinklers shall be permitted to be omitted from exterior exit corridors when the exterior walls of the corridor are at least 50 percent open and when the corridor is entirely of noncombustible construction.

8.15.7.5* Sprinklers shall be installed under exterior projections greater than 2 ft (0.6 m) wide over areas where combustibles are stored.

 

[steveray]

What CDA posted is for "projections" (marquis, overhangs, and the like), not if there are full walls and combustible roof(8.15.7.4)....Just for clarification

 

[JBI]

FRTW for the roof frame or pressure preservatively treated wood?

 

[Mr. Inspector]

Are both buildings on the same property?