Home Garden

How to Fix Condensation From Bathroom Vent Pipes Dripping in the Attic and Wetting the Ceiling

A bathroom vent pipe or duct that's not insulated may produce water damage inside your attic, even though the humid air from the bathroom flows outside the house. On cold days, the attic does not heat up like the rest of the house, causing the vent pipe to become cold as well. When the hot and humid air flows through the inside of the pipe, the moist air inside the attic may condense on the pipe, leading to water dripping onto your ceiling.

Things You'll Need

  • Screwdriver
  • Insulation sleeve
  • Ladder
  • Hammer
  • Pry bar
  • Roof cement
  • Drywall saw
  • Wall patch
  • Putty knife
  • Paintbrush
  • Paint
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Instructions

    • 1

      Climb into your house’s attic and locate the bathroom vent pipe. If you don't see an insulation sleeve over the vent pipe, loosen the hose clamp connecting the vent pipe to the vent opening in the roof.

    • 2

      Slide a pipe insulation sleeve over the pipe. Reconnect the pipe to the vent opening in the roof, tightening the hose clamp over the pipe and the insulation sleeve to hold it in place.

    • 3

      Loosen the hose clamp on the other end of the pipe and slide the insulation sleeve until it covers the rest of the pipe. Insert the pipe back over the fan housing’s exhaust opening and then tighten the hose clamp over the connection and the insulation sleeve.

    • 4

      Climb onto your house’s roof to inspect the hood over the bathroom vent’s opening. Reposition the hood if its flange does not sit under the roof shingles above it, pulling out the nails holding the flange in place and lifting up the higher shingles with a pry bar. Apply roof cement to the underside of the shingles that sit over the hood’s flange, and then press the shingles over the flange.

    • 5

      Cut out any portion of the ceiling that sags from the moisture damage, using a drywall saw. Spread wall patch into the opening, if you had to cut out any portion of the ceiling, using a putty knife. Scrape away bubbling or cracked paint with the putty knife, and then brush on fresh paint once the ceiling damaged has dried to the touch.