The minimum separation of sprinkler from a horizontal obstruction shall be determined by the height of the deflector above the bottom of the obstructions as shown in the below Table and Figure. Sprinklers shall be permitted to install with deflector at or above the bottom of the structure member to a maximum of 22in. (559mm) below the ceiling / roof deck when the sprinkler is installed in conformance with Table 4 – 4.1.3.1.2 shown below.
Because hot air generated by fires tends to dissipate towards ceiling and gradually accumulated forming the gradient, response of detectors may be delayed by placing this equipment remote from ceiling.
Position of Deflector when Located above Bottom of Obstruction
Distance from Sprinkler Maximum Allowable
Distance to Side of Obstruction Deflector above Bottom of Obstruction