# Sprinklers for trellis?



## Yikes (Jul 29, 2011)

I have a client who is retrofitting an old building with sprinklers.  The building has rooftop parking with a metal shade structure over it (metal beams, columns and roof panels , like a carport).  The plan checker wants this covered parking area sprinklered, but my client can't afford it.  He is willing to reverse-engineer / remove portions of the roof panels to reach a point at which sprinklers will not be required, even if that means stripping it down to the frame.

I'm not a sprinkler designer - - so the question is, at what point would sprinklers not be required?

A) Is it when the structure no longer meets the CBC 1502 definiton of roof assembly, because it does not provide weather protection?

B) If the answer to (A) is "yes", then how do you define that?  If he removed 51% of the roof covering (every other panel), would that be sufficient?

C) Could he remove the metal panels, replace them with shade cloth, and not have to sprinkler the  remaining steel frame?

D) Does NFPA require sprinklers on outdoor trellises?  What is the threshold / difference between a trellis and a roof, from a sprinkler design standpoint?


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## cda (Jul 29, 2011)

how many sq ft is the parking area?

how many sq ft is the canopy over it?

the normal criteria is anything over four feet has to be sprinkled

about the only criteria I know is for solid shelving and if you have oepningsover 50% it is not considered solid

I guess throw at the reviewer different ideas and see what sticks, the fabric may do it


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## cheyer (Jul 30, 2011)

It will also vary greatly depending on what the local ordinance is....for example, in my city we have basically a zero square foot ordinance for sprinklers...so anything over 500 square feet that isn't a shed gets sprinklered.......


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## cda (Aug 1, 2011)

do not think this helps you any, plus if you have 70% opening, not much cover left

Open-Grid Ceilings. The term open-grid ceilings as used in this standard refers to ceilings in which the openings are 1/4 in. (6.4 mm) or larger in the least dimension, the thickness of the ceiling material does not exceed the least dimension of the openings, and the openings constitute at least 70 percent of the ceiling area.

sounds like pitch fabric or over 50 opening


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## Yikes (Aug 1, 2011)

The parking area on the rooftop is over 20,000 SF.  If we removed 100% of the roof covering, but left the frame intact, the frame would be a grid of steel beams approx. 20 foot on center, both directions.

Would te beams need to be sprinklered?

CDA: do you have a code citation or commentary reference # for your comment above?

Thanks!


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## cda (Aug 1, 2011)

sorry, that costs extra

NFPA 13  2010 edition

A.3.7.2 Unobstructed Construction. The following are examples of unobstructed construction. The definitions are provided to assist the user in determining the type of construction feature.

3.9.3.8 Solid Shelving.   Solid shelving is fixed in place, slatted, wire mesh, or other type of shelves located within racks. The area of a solid shelf is defined by perimeter aisle or flue space on all four sides. Solid shelves having an area equal to or less than 20 ft2 (1.9 m2) shall be defined as open racks. Shelves of wire mesh, slats, or other materials more than 50 percent open and where the flue spaces are maintained shall be defined as open racks.

8.15.7* Exterior Roofs, Canopies, Porte-Cocheres, Balconies, Decks, or Similar 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 roofs, canopies, porte-cocheres, balconies, decks, or similar projections exceeding 4 ft (1.2 m) in width.

8.15.7.2*   Sprinklers shall be permitted to be omitted where the canopies, roofs, porte-cocheres, balconies, decks, or similar projections are constructed with materials that are noncombustible, limited-combustible, or fire retardant–treated wood as defined in NFPA 703, Standard for Fire Retardant–Treated Wood and Fire-Retardant Coatings for Building Materials.

8.15.7.3    Sprinklers shall be permitted to be omitted from below the canopies, roofs, porte-cocheres, balconies, decks, or similar projections of combustible construction, provided the exposed finish material on the roofs, canopies, or porte-cocheres are noncombustible, limited-combustible, or fire retardant–treated wood as defined in NFPA 703, Standard for Fire Retardant–Treated Wood and Fire-Retardant Coatings for Building Materials, and the roofs, canopies, or porte-cocheres 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 roofs, canopies, or porte-cocheres 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 roofs, canopies, porte-cocheres, balconies, decks, or similar projections greater than 2 ft (0.6 m) wide over areas where combustibles are stored.

     (1)Bar Joist Construction. The term bar joist construction refers to construction employing joists consisting of steel truss-shaped members. Wood truss-shaped members, which consist of wood top and bottom chord members with steel tube or bar webs, are also defined as bar joists. Bar joists include noncombustible or combustible roof or floor decks on bar joist construction with top and bottom chord members not exceeding 4 in. (102 mm) in depth. [see Figure A.3.7.2(a) and Figure A.3.7.2(b) for examples of bar joist construction.]

     (2)Open-Grid Ceilings. The term open-grid ceilings as used in this standard refers to ceilings in which the openings are 1/4 in. (6.4 mm) or larger in the least dimension, the thickness of the ceiling material does not exceed the least dimension of the openings, and the openings constitute at least 70 percent of the ceiling area.

don not think any of this helps you,   suggest fabric or see if the plan reviewer will give you some hints of what they will allow if anything.

I would say no if you took the cover off the top you do not have to do anything else


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## JustReid (Aug 15, 2011)

You're in So Cal?  If there is no sprinkler protection on the roof, you may be required to provide Class II hose connections on the roof. I have seen this in Southern California quite a bit.


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