Distance between sprinklers and the roof or ceiling Distance between sprinklers and the roof or ceiling yassinemzili (Civil/Environmental) (OP) 10 Jun 11 11:06 what is the distance between sprinklers and the roof or ceiling?and tne lenght of the nippel? RE: Distance between sprinklers and the roof or ceiling skdesigner (Mechanical) 10 Jun 11 11:16 For standard spray heads in unobstructed construction, 1"-12" measured from deflector to deck. The length of the nipple (sprig), if any, depends where your branchline is in relation to the ceiling. If you have to run it low to clear beams, the length of the sprig is the distance from the outlet fitting to put the deflector between 1 and 12 inches from the deck.For obstructed construction, see NFPA 13 2010 18.104.22.168.2. Basically, the sprinkler can be installed from 1 to 6 inches below the structural members, up to a maximum of 22 inches from the roof deck.