What materials are acceptable for venting residential bath fans?
This question often comes up because of the lack of specific language concerning bathroom exhaust ventilation in the Oregon Dwelling Specialty Code (ODSC). The 2003 ODSC, Section M1501.1 states: “Where exhaust duct construction is not specified in this chapter, such construction shall comply with Chapter 16.” Since Chapter 15 does not specifically address exhaust ducting for bathrooms, we must glean the information from the requirements found in Chapter 16. Chapter 16 has general requirements for all ducting and doesn’t specifically address “bathroom exhaust” ducts, so to help simplify the intent of the code and to answer commonly asked questions concerning exhaust-fan installations, the following shall apply as a minimum requirement for a “typical” bathroom exhaust installation in a one- and two-family dwelling; • Permits are required for new installations and replacement of a bathroom-type exhaust fans. • Plans are not generally required for exhaust fans installed in a one- or two- f
