Introduction

Installing a Bathroom Vent Fan tout »
Installing a ventilating fan in your bath will help eliminate fogged-up windows, steamy mirrors and stale odors. But more importantly, it will help prevent moisture-related problems, such as the growth of mold and mildew. Here, This Old House general contractor Tom Silva shows the proper way to install a bath vent fan. In this particular installation, Tom ran the exhaust duct into the attic and through a sidewall to the outdoors.

Other venting options includes running the duct up through the roof or down through the soffit. Note that the fan must always exhaust to the outdoors; never allow the duct to simply blow into an attic, crawlspace or other enclosed area. Also, the installation will go much quicker if you ask a spouse or friend to help be in the attic while you work from below, or to hand you tools while you’re on the ladder.
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    Tools List

    • caulk gun
      Caulking gun with silicone adhesive,
      for adhering wall cap to house siding
    • speed square
      Layout square
    • drill
      Drill-driver with 4½-inch hole saw,
      for cutting duct hole through sidewall
    • spade bit
      Extra-long, 3/8-inch-diameter spade bit,
      for drilling reference hole through ceiling
    • jigsaw
      Jigsaw,
      for cutting hole in bath ceiling
    • 16-foot tape measure
      Tape measure
    • eye goggles
      Goggles
    • extension ladder
      Extension ladder
    • ladder
      Stepladder

    Shopping List

    1. VENT FAN

    2. TARPS

    to protect floor and fixtures from dust



    3. 90-DEGREE SHEEET METAL DUCT ELBOW

    to connect flexible duct to vent fan



    4. 12-INCH CONNECTOR DUCT

    5. CABLE CONNECTOR

    6. WALL-CAP KIT

    7. FOIL DUCT TAPE

    8. DUST MASK