Why Is My Bathroom Vent Flapper Making Noise From The Wind?

Stacy Randall
by Stacy Randall

When you’re trying to relax in a warm bath, you might play some soft music or prefer perfect silence. What you likely don’t want to hear are banging or slapping sounds coming from your bathroom vent. However, if it’s windy outside, then that’s exactly what you end up listening to while you’re trying to relax.

If you hear noise from the bathroom fan when it’s windy, there’s an easy explanation. It’s because the wind is picking up the vent flapper and dropping it down repeatedly. You can resolve the issue by adding sound absorption, weight the damper, or replace it with a spring-loaded design.

A bathroom fan moves moisture out of bathrooms, so you don’t end up with mold, mildew, and other unpleasant issues. It’s a good idea to run it for about 20 minutes following a hot shower to dispel steamy air. It’s also helpful to freshen things up, but it can be a pain if it gets noisy when it’s windy.

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How Do Bathroom Fans Work?

A bathroom fan, also known as an exhaust fan, has one main purpose: ventilation. It helps remove moisture and odors from the bathroom. Typically, you’ll find a bathroom fan installed near the tub or shower, the main source of a bathroom’s moisture.

The exhaust usually goes across from the air vent to help pull the fresh air through the bathroom. The fan helps draw out air from your bathroom, pulling it outside through a flexible or metal duct.

What If You Don’t Have a Bathroom Fan?

Without a bathroom vent, when your tub or shower creates steam, the steam won’t have a place to go. Therefore, it sticks around, forming condensation on the surfaces of your bathroom.

The unpleasant results of this phenomenon are things like mold, mildew, odors, and even damage to walls and other surfaces. In addition, the excess moisture can cause rotten drywall, peeling paint or wallpaper, warped wood, and similar issues.

How to Stop Bathroom Vent Flapper Noise When Windy

If you hear banging, rattling, slapping, or similar noises in your bathroom, the wind’s likely playing with the vent damper. You can try several things to stop the noise coming from your bathroom vent flapper when it’s windy outside.

Note: These repairs require attic access and getting on your roof. Ensure you wear the proper safety gear, like a roofer’s harness, before attempting the job.

Use Sound Absorption

For a quick, budget-friendly fix (or cover-up), you can dampen the sound from your damper (no pun intended). Use weather-proof foam tape to do the job. Attach the foam to the exhaust hood.

Position the foam where the flapper comes down on the metal. This method will allow your damper to open and close as it needs and help absorb the sound. You can purchase a roll online for about $15.

Add Some Weight

Using some silicone adhesive, attach a few small washers to the flap. Alternatively, you can use a few wheel weights, which come with strong adhesive backing and can withstand the elements. You can find wheel weights online for about $8 to $10 a pack.

This process can be a bit tricky, as you don’t want to add too much weight. Therefore, start with one weight and see how it works before adding too much. If using wheel weights, start out with one ¼-oz weight.

After all, the flapper still needs to be able to open easily when you turn on the fan. Otherwise, the flapper can’t do what it is supposed to do. However, you want it to be heavy enough that the wind can’t move it up and down too easily.

Replace the Damper

If your bathroom flapper makes noise due to the wind, it’s likely a thin piece of steel operated by gravity. It opens when the fan goes on, and then gravity drops it back down. These styles of flappers are popular, but wind can manipulate them very easily.

The ideal solution to eliminate your noise problem is to replace the damper with a spring-loaded backdraft damper. These types of dampers often feature a rubber gasket that creates an airtight seal when the flapper closes. This seal prevents unwanted air from coming into your home via your bathroom vent since it stays shut.

Therefore, it’s more difficult for the wind to pick them up and bang them around. Plus, the rubber seal also helps dampen noise and prevent leaks. Typically you can find spring-loaded dampers with center pins between 4 and 8 inches in diameter.

If your existing flapper is in poor condition, then it’s definitely wise to simply replace it. Check this out if your bathroom vent flapper is making noise from the wind.

Video: Another Quick Way to Fix It

How to Install a Spring-Loaded Backdraft Damper for Your Bathroom Vent

Before beginning your project, ensure you get the appropriate size backdraft damper. Measure the vent’s diameter to get a matching damper. If you’re unsure, bring the old damper with you to the hardware store and ask an employee for assistance.

Tools You Need for the Job:

  • Ladder
  • Roofer’s Harness
  • Screwdriver
  • Utility Knife
  • Roof Sealer
  • New Spring-Loaded Backdraft Damper
  • Caulking Gun

Step 1: Disconnect the Vent Tube

Identify the problem vent in the attic and disconnect the vent tube with the screwdriver. Make sure to put the screws to the side in a safe place for later.

Step 2: Locate the Noisy Roof Vent Flapper

Set up your ladder on steady ground and climb onto the roof. It’s a good idea to have someone else around, just in case you fall. Find the noisy vent flap on the roof.

Step 3: Remove the Old Vent

Carefully lift the shingles that surround the vent so you can access it. Next, use the utility knife to cut away any sealant around the vent. Finally, use the screwdriver to remove the vent.

Step 4: Install the New Spring-Loaded Damper

Position the new spring-loaded damper into place, ensuring that it is the right size. Next, slide the new vent under the shingles and screw it into place with the included screws. Then, using the caulking gun, run the roof sealer around the entire vent to seal all of the edges.

Step 5: Connect the Vent Tube

Carefully climb down from the roof and go back to the attic. Reconnect the vent tube from earlier using the same screws that you set aside.

Step 6: Test Your Work

Once you’ve completed the job, it’s time to test your work. Head to the bathroom and see if you still hear the annoying banging noise. Of course, you might have to wait for a windy day to see if your replacement really did the trick.

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Related Questions

What if the bathroom exhaust is making noise, but it isn’t a windy day?

If you hear noise coming from your bathroom vent on a calm day, then it’s likely something other than the flapper. It could be the fan itself. There could be dust or dirt on the fan; it could be loose, uneven, or out of alignment. When this happens, the fan can knock against the housing as it turns. You might also need to lubricate the fan if you hear a squeak, or it could be a bad fan motor. If you’re dealing with a bad motor, it’s most likely more cost-effective just to replace the fan.

What if I need to replace the bathroom exhaust fan?

Unless you have a lot of experience in electrical work, it’s best to call a pro. The cost of replacing a bathroom fan isn’t extremely high, between $75 and $200. The fan itself can cost anywhere from $75 to $300, depending on the model and size. Make sure you get the appropriate size exhaust fan for your bathroom. The larger the square footage, the more CFMs you need. CFM is cubic feet per minute and is a measurement of airflow. The fan should move one CFM per square foot of space. Therefore, if your bathroom is 100 square feet, you want to ensure the exhaust has at least 100 CFMs. 

Do I have to have an exhaust fan in my bathroom?

It’s a good idea to have a bathroom vent to tackle excess moisture and odors. However, not all areas require them. Therefore, it’s essential to check your local codes for what’s needed where you live. Sometimes, you may not be able to vent air to the outside, so you might need to look at other options. In some cases, if you have adequate airflow from another source, a bathroom window, then you won’t need a vent. However, ask yourself, will you leave the window open long enough every time you shower or take a bath?

Stacy Randall
Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent's former home, making it their own and learning a lot about life along the way.

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