Fire sprinkler protection of exterior balconies in a full NFPA #13 building.

[SprinklerDesigner2]

I have a three story hotel protected by a full 13 system having balconies with exposed wood beams, wood joists and tongue and grooved planks.

The building is not of Type V construction.

I know this has to do with 13R and Type V construction but....

[F] 903.3.1.2.1 Balconies and decks.
Sprinkler protection shall be provided for exterior balconies, decks and ground floor patios of dwelling units where the building is of Type V construction, provided there is a roof or deck above. Sidewall sprinklers that are used to protect such areas shall be permitted to be located such that their deflectors are within 1 inch (25 mm) to 6 inches (152 mm) below the structural members and a maximum distance of 14 inches (356 mm) below the deck of the exterior balconies and decks that are constructed of open wood joist construction.

would it be appropriate to position the dry sidewall sprinklers so they are 1 k ti 6 inches below structural members and up to 14 inches below the wood deck?

To top this off the top floor balconies are installed at a 30 degree angle.

 

[TravisMack]

I think the "letter of the law" of NFPA 13 will get you caught on that. However, from a practical standpoint, I think you are on the right track.

If you are 1-4" below the structure, can you maintain 12" below the wood deck?

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[SprinklerDesigner2]

OK, the sidewall on the top floor was not my idea.

 

[cdafd]

Not near 13 , but if you are installing a full 13 system, than follow for canopy??

Just orient the head to the slope and locate head per listing from ceiling

 

[SprinklerDesigner2]

cdafd, my real problem is the ceiling is not flat it has the 3"x8" rough sawed joists (on the photo I identified these as 2"x8" which was my mistake).

From NFPA #13 2013

8.4.2 Sidewall Spray Sprinklers.
Sidewall sprinklers shall only be installed as follows:
(1) Light hazard occupancies with smooth, horizontal or sloped, flat ceilings

With those beams it's not flat.

Ok, here is the real question I should be asking of the professional engineers around here.

Architectural drawings show dry pendents being used under these porches. These drawings are sealed and signed by a registered professional engineer in this state.

In my mind I should be able to assume the professional engineer for this project did some research or calculations to where he was able to conclude sidewalls could be used as shown because, given the width of the balcony or whatever else he wants to use, he has determined the sidewalls would offer an equivalent level of protection.

If I understand correctly what has been thrown at me a professional engineer can do this but I, as a certified technician, can not.

I don't have a problem with this as long as I don't get caught up in some huge cat fight between the AHJ and myself because I simply did what the professional engineer instructed me to do. Far to often technicians get specifications from professional engineers that say to effect "do it exactly the way I show it without any deviations except where it is not compliant to standards in which case the problems and cost associated with fixing my screw ups are yours alone."

In my mind the professional engineer signed and sealed those drawings and the problems should be his and not mine.

This is my greatest pet peeve, something I could rant about for hours but I'll turn it off now.

 

[SprinklerDesigner2]

Another thing is the specifications require that the drawings I prepare, the ones with the sidewall sprinklers under open wood joists, be sealed by a registered engineer before I sent them back to him.

I know several PE's that will seal drawings for me when needed but I will not ask anyone seal something like this. I could never ask someone to review and seal something I was not absolutely sure of.

 

[TravisMack]

I think the PE is trying to apply the loading dock diagram with the dry pendents at an angle...maybe???

I would just kick back an RFI and state the HSW can only be used under flat ceilings - then provide the definition in NFPA 13 for a flat ceiling. I would also include that the section for the dry pendents on an angle has the diagram referencing unobstructed construction, which this is not. At that point, you have kicked it back to the FPE to resolve the issue.

If he comes back and says this is what he wants regardless of NFPA 13 criteria, then I would kick back another that says you can't adhere to the specifications about a PE seal, because there is no other PE that will seal his idea without something in NFPA 13 that you can solidly hang on to.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com