Why Is My Bathroom Fan Leaking Water?

We don’t think much of our bathroom fans, do we? They get installed, we switch them on and off, and that’s about it. They do their deed.

However, like any other device or piece of equipment in your house, bathroom fans can and, over time, definitely will, give out and start malfunctioning. 

You may notice other problems with your bathroom fan, like leaks, for example. The thing with leaks, though, is that they sometimes do not indicate that your bathroom fan has started malfunctioning. 

If your bathroom fan is leaking water, the cause may be something you’ve never even thought of.

In this post, we’ll discuss why your bathroom fan is leaking water, how to fix that, and how to prevent bathroom fan leaks from occurring again. 

Let’s go!

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bathroom fan damage

Causes of Bathroom Fan Water Leak

We’ll go over the most likely causes first and then, as we move down the list, mention the least likely causes of your bathroom fan water leak.


Condensation is the result of warm, moisture-rich air coming into contact with a cooler surface, leading to the transformation of water vapor into liquid water that then leaks into your bathroom.

With bathroom fans, condensation typically occurs when warm and humid air generated during your showers or baths passes through the fan into a cooler environment, such as the attic, for instance.

As this warm air goes through the fan and its ductwork, the moisture within the air condenses, forming water droplets. Over time, this accumulated moisture can lead to bathroom fan malfunctions, water leaks, and subsequent moisture damage and mold development, which we will touch upon later.

Condensation is more likely to happen to folks who live in colder climates.

Roofing Leaks

You may be surprised to know that a roofing problem can actually be the culprit behind your bathroom fan water leak.

Yes, roofing leaks can reach your fan and continue down your bathroom and perhaps even other places. Damaged shingles, deteriorated flashing, or other compromised roofing materials can allow rainwater to infiltrate and reach your house.

Water tends to follow the path of least resistance. The framing and ductwork in your home often have channels through which water can flow. So, if the bathroom fan is located in a ceiling near the leak, rainwater can move along these and eventually reach the fan.

Improper Installation

This one also sucks to hear.

The installation of a bathroom fan involves more than just placing it in the wall; it requires careful attention to details such as sealing, ductwork connections, and having it vent the air outside instead of another room of your house. Installation errors can lead to leaks.

Here are some ways bathroom fans are improperly installed:

  1. Inadequate Sealing: If the fan is not properly sealed during installation, gaps can pop up between the fan “housing” and the ceiling or the ductwork connections. These gaps can allow air with vapor from the bathroom to escape into the surrounding areas, leading to the aforementioned condensation and subsequent leaks.
  2. Poor Ductwork Connections: The ductwork connected to the bathroom fan needs to be secure and tight. Improper connections or loose fittings also allow water to escape into the ceiling or attic. This not only leads to leaks into your bathroom but may also cause damage to the fan and your ceiling wall materials. If left untreated, you could eventually notice things like discolored edges in the walls, dripping from the actual ceiling, and cracks. 
  3. Incorrect Slope or Positioning: Bathroom fans are designed to move air out of your house, not keep it inside. If the fan is not installed with the correct slope or positioning, water may accumulate in the fan itself instead of being sent outside. In other instances, the humid air may be directed out of the fan into other rooms, such as your attic. 

Okay, we presented you with the most common causes, and now it’s time for you to take a look and stop the leak. This leads us too…

How to Stop a Bathroom Fan Water Leak

Okay, so we know this ain’t fun but it’s something you’ve got to do.

Here are some of the steps you should take to prevent your bathroom fan from leaking water.

Look at the Damper

For those who don’t know, a bathroom fan damper is a device used to control the flow of air in a bathroom fan. 

It manages the direction and volume of air movement, improves indoor air quality by ensuring that the fan effectively removes humid air, odors, and pollutants from the bathroom, and prevents backdrafts.

Backdrafts occur when outside air, including potentially dirty air or odors, is drawn back into the home through the fan. The damper prevents these from happening.

Now, despite having a great use case, these dampers may not work well at times, and this requires a replacement, usually carried out by electricians. 

Repair Your Roof Damage

It helps to paint a picture of what the ventilation system looks like in your attic and on your roof.

Your bathroom fan has a ventilation pipe or hood that goes through your attic and then connects to your roof. The air passes through this and is sent outside through the vent, which is the final exit point.

You may have damaged flashing, which the ventilation from your bathroom fan is usually near to.

If the water leaks through this flashing, it can continue through the vent hood or pipe down to your bathroom fan. Ensure that the flashing is intact with no cracks.

Also, look at your shingles and make sure they’re not damaged. Look for cracks, chips, and warping. All of these allow for water infiltration. See if you’ve even got missing shingles. 

If you found that your roof is leaking water that then ends up in your bathroom, it’s time to fix that. You may do this on your own or call a roofer.

Replace the Ventilation Hood or Seal

It may be the vent hood itself that is damaged. The plastic may have deteriorated or the corrosion or other weather-related damage may have occurred.

If you’ve checked and seen that your hood is indeed damaged, you should replace it.

In the case of damaged seals, you would have likely seen those while inspecting the roof. If replacing the seal, make sure the new one is airtight.

Insulate Your Attic

To prevent condensation in your bathroom fan ventilation, consider insulating your attic.

Attic insulation involves a lot of work and expertise, like understanding the R-values and how many layers you need, installing the insulation, potentially adding vapor barriers, and more.

If you can handle that, go for it, as professional insulation services can get quite costly.

But this is an effective method for combating and preventing condensation that causes your bathroom fan water leaks.

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As soon as you call the number below, you’ll be connected with a professional restoration company in your area. Free, with no advertising or commitment.

Additional Leak Prevention Measures

That was a whole lotta work to do if you were DIY-ing. Now, there are still some measures you may want to take to further “leak-proof” your bathroom fan, including:

  • Placing your bathroom fan to a different position, further away from your shower or bath
  • Replacing your bathroom fan every 5-10 years
  • Do not leave the fan running for long after you’re done with showering

How to Deal With Serious Leak Damage

Ah, here we go.

Some of you may have gotten really unlucky and had your bathroom fan leak causing other damage in your home, like mold and mildew growth, for example.

You may have had water spreading to your other rooms and soaking up your carpets and hardwood floors. 

In this case, you’d have to dry out your room(s) and remove the mold after the moisture source – your bathroom fan water leak – has been dealt with.

If you live in a particularly humid climate, you likely already have a dehumidifier. If not, get a dehumidifier (either buy it or rent it out) and start using it to bring the humidity levels down. Air movers can further help with drying because they’re great at targeting a specific damp spot.

If you’re struggling to fix the damage from the leak, consider calling a professional water damage restoration company. Use RepairSprout to find a 5-star restoration company near you with ease. 

Wrapping up

That’s it! This is quite a detailed post, so take your time to carefully examine your attic and roof to find the exact cause of the issue. Of course, for any additional help with water leak cleanup, we’re here to assist.

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