220.127.116.11 Distance Below Ceilings
(A) Where a vertical change in ceiling elevation within the area of coverage of the sprinkler creates a distance of more than 36 in. (900 mm) between the upper ceiling and the sprinkler deflector, a vertical plane extending down from the ceiling at the change in elevation shall be considered a wall for the purpose of sprinkler spacing as shown in Figure 18.104.22.168.1.3(A).
FIGURE 22.214.171.124.1.3(A) Vertical Change in Ceiling Elevation Greater Than 36 in. (914 mm).
(B) Where the distance between the upper ceiling and the sprinkler deflector is less than or equal to 36 in. (900 mm), the sprinklers shall be permitted to be spaced as though the ceiling was flat, provided the obstruction rules are observed as shown in Figure 126.96.36.199.1.3(B).
FIGURE 188.8.131.52.1.3(B) Vertical Change in Ceiling Elevation Less Than or Equal to 36 in. (914 mm).
- Installed with the deflectors within the horizontal planes of 1 in. to 6 in. (25 mm to 150 mm) below the structural members and a maximum distance of 22 in. (550 mm) below the ceiling/roof deck
- Installed with the deflectors at or above the bottom of the structural member to a maximum of 22 in. (550 mm) below the ceiling/roof deck where the sprinkler is installed in conformance with 184.108.40.206.2
- Installed in each bay of obstructed construction, with the deflectors located a minimum of 1 in. (25 mm) and a maximum of 12 in. (300 mm) below the ceiling
- Installed with the deflectors within the horizontal planes 1 in. to 6 in. (25 mm to 150 mm) below composite wood joists to a maximum distance of 22 in. (550 mm) below the ceiling/roof deck only where joist channels are firestopped to the full depth of the joists with material equivalent to the web construction so that individual channel areas do not exceed 300 ft2 (27.9 m2)
- *Installed with deflectors of sprinklers under concrete tee construction with stems spaced less than 71/2 ft (2.3 m) on centers, regardless of the depth of the tee, located at or above a horizontal plane 1 in. (25 mm) below the bottom of the stems of the tees and complying with Table 220.127.116.11.2
FIGURE 18.104.22.168.3.3 Horizontal Clearance for Sprinkler at Peak of Pitched Roof.
*The 5 ft minimum dimension is measured from the intersection of the upper and lower truss chords or the wood rafters and ceiling joists.
FIGURE 22.214.171.124.4 Sprinklers Under Roof or Ceiling in Combustible Concealed Spaces of Wood Joist or Wood Truss Construction with Members Less Than 3 ft (0.91 m) on Center with a Slope Having a Pitch of 4 in 12 or Greater.
FIGURE 126.96.36.199.5.1 Arrangement of Sprinklers Under Two Sets of Open Joists — No Sheathing on Lower Joists.