How to Vent an Enclosed Shower

Choose the location for the exhaust fan in the enclosed shower. Take the fan unit upstairs into the attic to the corresponding location above the ceiling. If you must, shift it a few inches over so the fan will rest against a ceiling joist. Trace a line around the fan on the ceiling with the pencil, then set the fan to one side.

Drill a hole through the ceiling at each corner of the box you just traced with the pencil. With the help of those guiding holes, cut out the box using a drywall saw.

Follow the manufacturer’s directions for flush mounting the exhaust fan to the ceiling. Typically, you need to remove the unit’s grill face. Place the unit flat against the ceiling joist and over the hold you cut out with the saw. Lower the fan until its bottom end is about a quarter inch from the interior ceiling surface. Fasten the fan to the ceiling joist using the screws that came with the mounting kit, according to the manufacturer’s instructions.

Choose the location for your exhaust fan’s power switch on the wall inside the bathroom. Place the switch box against the wall and trace around it with the pencil. Cut out the drawn box with the drywall saw.

Pick up the 3-wire NM cable first. Run it from the cut out in the wall up to the exhaust fan in the attic. Run the 2-wire NM-cable from the cutout in the wall to the panel supplying power for the bathroom. Pull the cables into the switch box. Cut down any excess length with the wire cutter.

Screw the switch box into the wall until it is securely in place and does not shift.

Choose the location where the exhaust fan will vent out of the attic through the roof. Place the face of the ducting against the interior side of the roof and trace it with the pencil. Cut out the circle with a reciprocating saw.

Pick up the vent cover tailpiece from the exhaust fan mounting kit. Carry it as you climb up the ladder to reach the exterior of your roof. Use the crowbar to pry up the shingles around the hole you cut with the reciprocating saw. Insert the vent cover tailpiece through the hole in the roof.

Return to the attic. Slide a hose clamp over one end of the ducting, the slip that same end over the vent cover tailpiece where it sticks down into the attic. Tighten the hose clamp to hold the ducting in place. Slide a hose clamp over the other end of the ducting, then slip that end over the exhaust outlet on the fan. Keep it in place using the hose clamp.

Climb back up onto the roof. Install the vent cover according to the manufacturer’s instructions. Usually you place the vent cover flange over the tailpiece and nail the flange to the roof with self-sealing nails. The vent cover slides on over the flange. Patch the shingles around the vent cover with the self-sealing nails and roofing cement.

Wire the exhaust fan according to the manufacturer’s instructions. Typically, the black circuit wire in the NM cable connects to the fan motor; the white wire connects to the neutral wire lead and the grounding wire connects to the grounding lead.

Follow the manufacturer’s instructions to connect the wires in the switch box to the switch that controls the fan. Usually, the two neutral wires are connected. You connect the black wire from the fan to the switch at the same place the circuit wire from the electrical panel connects. Screw the switch and cover plate into place.

Take the exhaust fan grill back to the bathroom. Attach it to the exhaust fan according to the manufacturer’s instructions.