Bathroom Exhaust Fan Leaking Water When it Rains

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Water leaks are some of the most horrifying experiences for any homeowner. It is worse when coming from unexpected places, such as the bathroom exhaust fan. The system is enclosed, and figuring the problem might take a while.

It leaves you wondering why your bathroom exhaust fan leaks water when it rains.

Your bathroom exhaust fan can leak water for reasons such as vent deterioration, poor vent installation, and condensation build-up. These problems can be repaired and should be worked on fast. Delaying the repairs can lead to major defects that are challenging to deal with.

I will be covering the causes and solutions for these leaks in detail. Keep reading to know more.

Causes of Bathroom Exhaust Fan Leak When it Rains


Some causes of bathroom leaks are common, while others are rare. Some of the reasons your bathroom exhaust is leaking when it rains are:

Condensation Build-Up

It happens when the dampers are not working correctly. This problem is more prevalent during cold weather, where warm air from the bathroom gets condensed in the vents. The vents are often cold because of the external temperature.

The warm air/steam from the bathroom hits the cold vents and condense. It then becomes dense, and instead of moving outside, it starts getting back into the bathroom. You will begin to notice leaks when this happens for a few days.

Poorly Installed Vents

We are always reminded to hire experienced professionals to help us with home renovations. Instead of heeding the advice, we fall for installers whose prices are ridiculously low, hoping to save something in the long run. Result? A disastrous and shoddy work.

A slight mistake during vent installation can affect the entire system. Unqualified installers are always in a hurry to finish one gig and jump to the next. After installation, the vents barely serve you before you start observing leakages.

The solution is having the entire vent system re-done, costing you more time and money on the project.

Water on the Roof

Water will definitely accumulate on the roof when it rains before getting drained away. Your roof can also have water as a result of the snow melting. If your bathroom vent system is properly functioning, there should be no need to be alarmed.

However, this water can start dripping into your bathroom when the vent cover is damaged. It can also be a case of poor insulation on the vent.

Deteriorated Vents

Bathroom vents deteriorate after some time. The condition makes them not work as they should since they tend to work slower. So, much of the warm air remains in the vent instead of being released outside.

Because of the temperature difference, the trapped warm air starts condensing. The result is water leaks from your exhaust fan.

Wrong Fan

Your bathroom should be fitted with the right fan depending on its size and frequency of use. If you have a large family, the frequency of your bathroom’s use is high, and a large fan is appropriate to drive the warm air away.

Also, when your fan is wrongly positioned, it is less effective. Instead of driving the warm air away, it creates a condensation problem.

Improper Fan Run Time

Fans have an annoying sound when running, and it is a huge turndown to homeowners. To avoid the noise, most people only run it for a few minutes when taking their showers and quickly turn them off immediately after stepping out of the shower room.

Well, that is an improper way of running your fan. It does not allow enough time for the fan to get rid of the steam. Instead, the warm air is partially driven away from the bathroom while the rest condenses in the vents. It then comes back as water droplets, causing leaks in your bathroom.

Despite the horrible noise created by the fan, let it run for at least 15 minutes once you are done showering. It efficiently removes all the steam from the exterior.

Defective Roof Vent Cover

A faulty roof vent cover is another reason your bathroom fan gets leaky when it rains. The roof vent cover is always surrounded by flashing to prevent rainwater get inside. The vent cover allows water to seep inside and down through your vent pipe when faulty.

How to Fix Water Leakages from Your Bathroom Exhaust Fan

Leaks in the bathroom can be repaired and should not make you panic. Here are a few ways:

Check Your Dampers

The dampers should be fully functional to prevent condensation from occurring. That is, they should only open when pushed by the warm air from the inside and not from the outside.

If yours are weak and remains open throughout, consider replacing them with functional ones.

Replace the Deteriorated Vents

Stop forcing the already worn vents to keep functioning as you are creating a problem that will be expensive to handle. Instead, consider replacing the deteriorated ducts with new ones. The new vents will help move warm air from your bathroom, and the leaking problem will no longer be an issue.

Replace the Fan and Adjust Location

If your fan is the cause of your bathroom leak, consider getting a big one to accommodate your needs. If you have the right fan size but still have fan leaking-related challenges, consider moving it to a convenient location.

For example, if your fan is placed directly on top of the showerhead or the bathtub, it might not function properly. Consider moving it away from such positions to ensure it does not come into contact with the very hot steam.

Have Your Vents Properly Installed

If you ignore the poorly installed vents, you end up having a recurring problem. Even if you have recently installed your ducts, you should have them properly installed by a qualified professional for a long-term solution.

Check Your Roofing Material

The leaks may have nothing to do with your vent system but everything with your roofing material. It can be a missing shingle, holes, or missing nails. Consider making the necessary repairs to such damages to prevent water from getting to your bathroom.

Use a Dehumidifier

Everything in your bathroom could be functioning properly, but you live in a humid area. The humidity can often be high, making your bathroom moist most of the time. If the fan is not enough to get rid of the moisture, consider having a dehumidifier to get rid of the problem.

Your bathroom should be comfortable, and you should enjoy its environment as you take your baths. When leaks start appearing, it feels scary, and the thought of mold toxicity keeps running through your mind. If the leakages have been there for a long time, you should have your exhaust fan treated before repairs.

I hope this information helps you understand the causes of leakages in your bathroom exhaust fan and how you can repair them. These repairs are not mostly DIYs, and you should avoid doing them alone. Allow experienced professionals to help you with the work.

They can also help you have the same problem recurring.

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