Duct Through the Roof

• 1). Turn off the power to the bathroom.
  
  
• 2). Climb up in the attic. Place the unit against a ceiling joist. Outline the unit with a pencil. If no attic is present, use a stud sensor to locate a ceiling joist. Hold the unit in place and draw an outline. Cut the hole with reciprocating, saber or keyhole saw.
  
  
• 3). Secure the vent to the joist with screws.
  
  
• 4). Push back or cut the insulation. Some units require a 6-inch gap between the insulation and the unit.
  
  
• 5). Cut pieces of 2-by-4 lumber to fit between the ceiling joists. Secure the lumber with nails or screws.
  
  
• 6). Trace a circle large enough for the roof cap end piece on the underside of the roof. Drill a hole large enough for a saw blade. Cut the hole with a saw.
  
  
• 7). Climb up on the roof. Cut the shingles around the roof vent, taking care not to damage the roofing paper. Remove the cut pieces.
  
  
• 8). Apply roofing cement to the flange on the roof cap. Slide the roof cap under the shingle while inserting the cap into the hole.
  
  
• 9). Apply roofing cement to the shingles. Install the shingles on the sides of the roof cap.
  
  
• 10
  
  Attach the flange to the roof using roofing nails. Cover the heads of the nails with roofing cement.
  
  
• 11
  
  Climb into the attic. Slide the flexible duct onto the unit and the roof cap. Use a zip tie to secure the duct work in place on both ends. Wrap the connections with duct tape.
  
  
• 12
  
  Connect the wiring according to the manufacturer's instructions. If wiring in the attic does not exist, run cable to the unit and the wall switch.
  
  
• 13
  
  Plug the motor into the built-in outlet on the unit.
  
  
• 14
  
  Run the wiring from the unit to the wall switch. Use fish tape to aid in pulling the wire through the electrical box in the wall.
  
  
• 15
  
  Connect the white wires with wire nuts. Connect the ground wires with wire nuts.
  
  
• 16
  
  Cut two wires 6 inches in length. Strip both ends of the wires. Connect the two black wires and one 6-inch length of wire with wire nuts. Do the same for the red wires--this is necessary for a fan/light/heater switch that has power entering the switch box.
  
  
• 17
  
  Connect the red wires to one switch terminal. Connect the black wires to the other switch terminal. Secure the switch to the wall. Restore the power.