Combustible Overhang & NFPA 13 (2007)

[NBAIRMEN]

Good day all,
I have a situation that is giving me some grief. Any input would be greatly appreciated. I currently have an existing building that is being retro fitted with sprinklers (NFPA 13 2007). The building is a single story block and brick structure with no combustible concealed spaces and the “attic” space is also noncombustible type construction. However, there is a “decorative frame element” installed on the exterior of the building. This feature runs the entire perimeter of the building. It starts on top of the parapet wall and slopes outward and downward to a 2’-0 width. The total height is 4’-0”. It is a wood framed structure with asbestos shingles on the outside and a cement asbestos board bottom or soffit. This element is there to give the illusion of a slope “roof” on a flat roof building and there is no storage under it. There are no penetrations through the wall into the interior of the building and most of this structure is above the roof line on the parapet wall. Would this feature be considered a combustible concealed space and would sprinklers be required? And is it correct to label this a decorative frame element or combustible overhang?

 

[stookeyfpe]

Sounds like a mansard roof. It could be a candidate for Section 8.15.2.18.1 based on the 2010 edition of NFPA 13.

 

[cdafd]

Section 8.15.2.18.1 based on the 2010 edition of NFPA 13

miss a couple of numbers or dots???

 

[cdafd]

If it is on the roof, or above the roof line, and there is no opeinging into the building, it should not require sprinklers

a plan would help a great deal to visualize this better

 

[NBAIRMEN]

I was thinking 8.15.1.2.18 as well. My only hesitation is 8.15.1.2.18.2 This overhang structure was built in the 70’s and I don’t think they would have installed any kind of firestops/blocking. The overhang satisfies the rest of the requirements. Sorry but I do not have any kind of drawing/detail.
It’s not part of the roof but rather a framed member anchored to the outside of the exterior wall. The owner could just remove this feature because it is just cosmetic but I don’t know if the asbestos materials would be an issue.

 

[cdafd]

Sorry I got my numbers and dots mixed up

Good section

Well they could price sprinkling it or price making it comply with the section and see which one is cheaper and cheaper in the long run

 

[stookeyfpe]

When in doubt extend the protection. I've responded to several structure fires where electric signs were attached to mansards roofs, ignited, and I had a 2nd alarm assignment cutting mansard roof sections open so we could extinguish the fire. A single branch line of properly designed sprinklers would have saved a lot of hassle and saved me from worry about hurting my people.

 

[acb324]

I always err on the side of caution as stookey says, but why wouldnt this fall under 8.15.7 - exterior roofs, canopies, porte-cocheres, balconies, decks or similar projections? I would think since the projection does not exceed 4 feet in width from the building it doesn't require protection.

 

[cdafd]

Does not look like a 8.15.7????

 

[Sdpaddler50]

I was curious as to how this one would play out, when it was posted this morning. As others have noted, there are good reasons to run a line of sprinklers. The area may be small, but if a fire starts in a comb. concealed space, and really gets going, it can spread throughout the entire facility. Fire loss history proves it. I dont think I would ever sign off on the omission of heads in such a space as a consultant. And if push came to shove, and I had to accept it because it met code/nfpa, i would go on the record to the owner/tenant, etc that its a bad idea.

 

[acb324]

I missed the concealed space portion. I was just picturing something akin to a slanted awning but up at the parapet height. Agreed with Sdpaddler, I would definitely go on record recommending sprinklers.