Common Issues Resulting From Bath Fan Venting Problems (And What To Do About Them)

Date Published: May 28, 2019

Bathrooms are one of the most humid, damp, and moisture-prone areas of the home, which means that bath fan venting is critical for preventing issues like wood rot or mold growth in the home.

Bath fan venting problems often occur because it is an afterthought in many renovations, and even in new home builds. If your bathroom has poor venting, a low-quality fan, or vents into the attic or too close to your home, it can cause serious problems. Ensure your bath fan is installed properly.

So, in this article, we’ll look at a few common issues resulting from bath fan venting problems, and how you can fix them.

1. Excessive, Prolonged Humidity In Your Bathroom

If you feel like your bathroom is constantly humid and your bath fan is not venting properly, this can cause a variety of issues– from peeling wallpaper to the growth of mold and mildew. An overly-humid bathroom is never a good thing.

Your fan could be too small for your ducting – or your ducting could be too large for your fan. Both of these things would cause airflow issues.

Alternatively, the duct could be too long or improperly routed with too many kinks and bends, resulting in an overly-humid environment in the pipe, and reducing its ability to remove moisture from your bathroom. You should have your fan and ducting examined by a professional.

2. Leaking Or Dripping Around Your Fan In The Winter

If you notice that there is a lot of leaking or dripping from your fan in the winter, this is probably because your duct is not insulated properly. When the warm, moist air blown by your fan meets cold air, this will cause condensation – and in turn, this will result in leaks.

To solve this issue, we recommend insulating the outside of your pipe with fiberglass insulation or an insulation wrap. This will keep the air inside warm until it is exhausted outside – reducing the risk of condensation.

Concerned about possible mold in your home? Test your indoor air for mold spores with our Mold Air Sample Test. We take 3 samples throughout your house including any problem areas you suggest. Ensure you are breathing clean air. This can be done on its own or during a home inspection.

3. Moisture (And Mold) In The Attic

If your bathroom fan exhausts into your attic – and not outside of your home – you could start having serious issues with moisture and mold.

You should never have a bathroom vent terminate in your attic – it must exit your roof directly, and ideally be far away from soffits and roof overhangs, which could retain the moisture and divert it back into the attic.

Ensure that the vent piping exits your home through the roof, and use the appropriate termination cap to ensure proper exhaust flow. If your bathroom fan continues to vent into your attic, you risk serious, permanent damage to your home.

Bath Fan Venting Problems

Poor attic fan venting was found one of our recent inspections. This causes moisture issues on the roof decking.

Know How To Recognize – And Address – These Common Bath Fan Venting Problems

Properly installed, insulated, and vented bath fans are key for preserving your home, and preventing moisture-related problems like leaks, mold, and mildew. So make sure your bathroom is in great shape – be on the lookout for these problems, and take the proper steps to address them.

We are always on the lookout for bath fan venting problems. It is a common defect that our inspectors call out. If you are in need of a home inspection or would like us to take a look at your bath fan, learn more about our services here.

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About the Author: Chris Scott

Chris Scott is an ASHI certified home inspector with multiple years of experience in home inspections, blower door testing, duct leakage testing, and Boulder Rental License Inspections. Chris is also the Website Coordinator for Scott Home Inspection.

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