Chimneys shall be provided with crickets where the dimension parallel to the ridgeline is greater than 30 inches (762 mm) and does not intersect the ridgeline. The intersection of the cricket and the chimney shall be flashed and counterflashed in the same manner as normal roof-chimney intersections. Crickets shall be constructed in compliance with Figure R1003.20 and Table R1003.20.
TABLE R1003.20 CRICKET DIMENSIONS
FIGURE R1003.20 CHIMNEY CRICKET
TABLE R1003.20 CRICKET DIMENSIONS
| ROOF SLOPE | H |
| 12 ‒ 12 | 1/2 of W |
| 8 ‒ 12 | 1/3 of W |
| 6 ‒ 12 | 1/4 of W |
| 4 ‒ 12 | 1/6 of W |
| 3 ‒ 12 | 1/8 of W |
For SI: 1 inch = 25.4 mm.
FIGURE R1003.20 CHIMNEY CRICKET