sprinklernotes Dry Pendent Sprinkler at 45-Degree Angle You have asked the following question: “Most of our installations are multi-family projects such as apartment buildings. The exterior balconies and porches are required to be protected, and since these areas are unheated, dry sidewall sprinklers would be installed. Lately, the longer barrels lengths do not have room inside the typical stick-framed 2 x 4 walls. One customer in particular has insisted on dry pendents installed at a 45-degree angle. There is no guidance that specifies how far down to place the deflector or its minimum/maximum distance from the outside walls. Are dry pendents installed at a 45-degree angle an acceptable approach?”
We have reviewed NFPA 13, Standard for the Installation of Sprinkler Systems, 2016 edition as the applicable standard. Our informal interpretation is that while this practice is detailed in the annex, the orientation violates the listing and the requirements of section 8.6.4.2. While Figure A.8.15.7 shows a diagram of dry pendent sprinklers for the protection of covered platforms, loading docks, and similar areas, this issue was specifically discussed during the first and second drafts of the 2019 edition of NFPA 13. A first revision was made based on Public Input No. 456 and removed Figure A.8.15.7 and the associated text. The substantiation was that the sprinkler is used outside of its listing. Further discussions took place during the second draft as Public Comment No. 167 regarding the issues with 2 x 4 exterior walls and how that is insufficient for the application of dry sprinklers supplied by wet pipe systems. New figures were proposed to show proper installations in exterior walls. Enforceable language in the standard clearly states the following: 8.6.4.2 Deflector Orientation 8.6.4.2.1 Unless the requirements of 8.6.4.2.2 or 8.6.4.2.3 are met, deflectors of sprinklers shall be aligned parallel to ceilings, roofs, hips, or the incline of stairs. 8.6.4.2.2 Where sprinklers are installed in the peak below a sloped ceiling or roof surface, the sprinkler shall be installed with the deflector horizontal. 8.6.4.2.3 Roofs having a pitch not exceeding 2 in 12 are considered horizontal in the application of 8.6.4.2, and sprinklers shall be permitted to be installed with deflectors horizontal. A pendent sprinkler installed at a 45-degree angle does not meet any of the requirements in the sections quoted above. With that said, there are better sprinkler technologies available today for that type of application rather than this approach. The use of flexible dry sprinkler or construction of heated soffits are better installation practices.
