Venting Through Closed Spaces
If the vent piping passes through a closed space, a minimum clearance of 8” (20 cm) when installed horizontally, 6” (15 cm) when installed vertically should be maintained between the vent pipe and combustibles and noncombustibles. Be sure to follow local codes and vent manufacturers installation instructions.
For maintenance and inspection purposes, the following access panels are required.
●Two (2) inspection access panels large enough to allow access for venting inspection. One (1) of these access panels should be close to where the vent pipe enters the ceiling. The other access panel should be near the vent termination.
●A ventilation access panel with a 16 in2 (103 cm2) opening should be provided every 10 ft (3 m).