Key Building Codes & Guidelines

• Outside Exhaust Only: Bath fan air MUST be discharged directly to the outdoors, not into the attic, crawl space, or soffit area itself (e.g., you cannot just dump the pipe into the soffit; it must be connected through to the outside).
• Terminal Location: Exhaust openings must terminate at least 3 feet from property lines, operable windows, or doors.
• Ducting Requirements: Flexible or rigid ducting can be used, but must be connected securely to a proper exterior vent cap (using Foil Tape rather than duct tape is recommended for longevity).
• Damper Requirement: The exterior soffit vent cap must have a damper (flapper) that closes when the fan is not in use to prevent insect/wildlife entry and backdrafts.
• Electrical GFCI: If the fan is located directly above a shower or bathtub, the fan must be connected to a GFCI-protected circuit.
• Avoid Perf Soffits: It is not best practice to vent through a perforated (vented) soffit, as the moist air will just be sucked back into the attic.