Sprinkler Support Hangers
by Bob Armbrister, on Mar 4, 2020 12:00:00 AM
Q: We are building a new ER and an area of the existing building had to have some work done so that the new ER could connect to the old building. The existing ceiling was a "hard" ceiling and the existing sprinklers were hung below the ceiling. We now have a drop ceiling and the sprinklers are installed with the pipe above and the heads below the drop ceiling. The sprinkler installer is hanging the pipe where it touches duct, electrical conduit and is hung from the trusses. My question is, is this non-compliant?
A: It depends on the size of pipe and where it is supported from. Generally speaking, sprinkler piping may only be connected to the building structure, such as beams, trusses and decks. But there are some exceptions. Section 18.104.22.168 of NFPA 13-2010 says sprinkler piping must be supported independently of the ceiling sheathing, but they do allow sprinkler pipe up to 1½-inch or smaller diameter pipe to be supported from ceilings of hollow tile or metal lath and plaster. But this excludes acoustical tile ceilings, and gypsum board ceilings. Section 22.214.171.124.1 says unless the requirements of 126.96.36.199.3 apply (which allows special hangers for flexible piping), sprinkler piping shall be substantially supported from the building structure, which must support the added load of the waterfilled pipe plus a minimum of 250 lb. applied at the point of hanging. Section 188.8.131.52.3 discusses Flexible Sprinkler Hose Fittings, and says listed flexible sprinkler hose fittings and their anchoring components intended for use in installations connecting the sprinkler system piping to sprinklers shall be installed in accordance with the requirements of the listing, including any installation instructions. This allows the special hangers for flexible piping to connect to the grid of acoustical tile ceilings. Section 184.108.40.206 on Metal Decks, says branch line hangers attached to metal deck shall be permitted only for the support of pipe 1 inch or smaller in size, by drilling or punching the vertical portion of the metal deck and using through bolts. Section 220.127.116.11 says where sprinkler piping is installed below ductwork, the piping shall be supported from the building structure or from the ductwork supports, provided such supports are capable of handling both the load of the ductwork and the load of the pipe, the water inside the pipe and an additional 250 lbs. Remember, section 18.104.22.168 says sprinkler piping or hangers shall not be used to support non-system components. Take a look at the sprinkler system design drawings… often the sprinkler designer will specify where sprinkler piping is required to be supported. See if the installing contractor is following what has already been designed and approved. But, NFPA 13-2010, chapter 9 on hangers should take precedent over whatever the designer specifies.