Why Is My Bathroom Fan Leaking Water?

Bathroom Fan Leaking Water? Start With When It Drips

Water leaking from a bathroom exhaust fan usually comes from one of two places. Either moisture from the bathroom is condensing inside the fan duct, or water is getting in from outside, such as through a roof leak. The EPA lists leaking roofs among the common moisture problems in buildings. When the fan drips is the best clue to which one you have.

Drips After Showers in Cold Weather: Condensation

If the fan drips after showers, mostly in cold weather, condensation is the likely cause. The EPA explains that showers add moisture to the air, and that in cold weather moisture condenses on cold surfaces. When warm, humid air touches a cold surface, condensation may form. A fan duct that runs through a cold attic can be one of those surfaces.

The EPA's general advice for preventing condensation is to reduce the humidity, increase air movement, and cover cold surfaces with insulation. For showers, that means running the bathroom fan or opening the window while you bathe, and acting quickly when you see condensation collect. Whether your duct needs any change is a question for a qualified contractor, who can look at it in person.

Drips Only When It Rains: The Roof or Wall Vent

If the fan drips only during rain or snowmelt, an outside source such as a roof leak is likely. The EPA says roof and flashing details should keep water out of the house. A roofer can inspect the roof. Our guides to what to do about a roof leak and the signs of a roof leak cover what to look for.

A Duct That Ends in the Attic

The EPA says to use exhaust fans in bathrooms to remove moisture to the outside, not into the attic, and to vent bathroom exhausts directly outside rather than into an attic or other enclosed space. The CDC also advises using exhaust fans that vent to the outside of your home. A duct that ends in the attic, or one that has come loose, puts shower moisture into the attic. That is why the EPA says to vent outside. Moisture in an attic can lead to mold, which our guide to mold in the attic explains.

Is a Dripping Bathroom Fan Dangerous?

There are two risks to take seriously: electricity and the ceiling. Take them in this order.

• People first. If you see sparking or smoke, or hear buzzing from the fan or light, get everyone out and call 911.
• Gas. If you smell gas, leave and call the gas utility or 911 from outside. Do not flip switches on the way out, because Ready.gov says electrical sparks can ignite leaking gas.
• Electricity. If water is coming through the fan housing or its light, treat it as wet electrical equipment and do not touch the fan or its switch. The CDC says that when electrical equipment has gotten wet, you should turn off power at the main breaker or fuse, and never do it while standing in water. If reaching the panel means entering standing water, the CDC says to call an electrician. We would also not touch the panel or any switch from a wet floor.
• The ceiling. FEMA says to check the ceiling for signs of sagging, because water may be trapped in it. If the ceiling around the fan sags or bulges, anyone under it should leave the room, call 911 and stay out until it is safe. If it is dripping, call a professional.

The Electrical Safety Foundation International (ESFI) says a qualified electrician should evaluate water-damaged electrical equipment, because returning power without an evaluation could cause a fire or shock. That applies to a fan or light that has been wet.

How to Protect the Ceiling Around the Fan

Once the area is safe, you can limit the damage while you sort out the source.

• Catch the drips with a container, from a spot that is safe to stand in, and without touching the fan or its switch.
• Photograph the stain so you have a record of how it changes.
• Dry the area. The EPA advises drying water-damaged areas within 24 to 48 hours to prevent mold growth.
• Check the insulation above the ceiling. The EPA's cleanup guidance says wet fiberglass or cellulose insulation is discarded and replaced.

The EPA says drywall may be dried in place only if there is no obvious swelling and the seams are intact. Be careful about judging by touch or sight alone. FEMA says moisture is difficult to assess accurately that way, and the EPA lists the roof materials above ceiling tiles among the places hidden moisture and mold can be. A ceiling that looks dry may not be.

If the ceiling has a textured or popcorn finish, read about popcorn ceiling water damage before anyone scrapes or cuts it. Our guides on water stains on a ceiling and whether insulation can get wet explain more about what you may be seeing. If you spot mold on the ceiling near the fan, see how to get rid of mold on a bathroom ceiling.

Who Fixes a Leaking Bathroom Fan

The right person depends on where the water comes from. Here is how it breaks down:

• Drips after showers, mostly in cold weather: likely condensation in the duct. A qualified contractor looks at the duct.
• Drips only during rain or snowmelt: likely an outside source such as a roof leak, according to the EPA. A roofer fixes it.
• Water coming through the fan motor or light: it may be any of the above, and it has reached wiring. An electrician checks the fan and wiring.

Duct, roof and electrical repairs belong to those trades. The ceiling and insulation are a different job, and a water damage professional dries them. If the water is coming from somewhere else, such as a bathroom or pipe above, our guide on what to do about a leaking ceiling covers the other common sources.

When the Ceiling Around the Fan Needs Professional Drying

Call a water damage professional if any of these apply:

• The stain keeps spreading.
• The drywall is soft or sagging.
• Water reached the fan's light or wiring.
• The insulation above the ceiling is wet.
• The drip comes back every winter or every storm.
• There is a musty smell.

If the ceiling around your fan is stained and spreading, we can dry and restore it once the source is fixed. Our ceiling water damage drying and repair page explains how, and our bathroom water damage page covers the rest of the room. For repairs that follow drying, see how to fix a water-damaged ceiling, and for what repairs can cost, see the cost to fix ceiling water damage. Green State Restoration offers 24/7 emergency water damage restoration, so call us at (425) 300-6431 to talk about drying the ceiling.