Managing Ideal Indoor Humidity Level to Prevent Mold Growth

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How Reducing Humidity Levels Can Prevent Mold Growth

You may be surprised to learn that mold is growing in nearly every building and home in the United States. Mold grows so easily and quickly that it will start to sprout in a matter of days, given the right conditions. One of the key elements to the perfect environment for mold growth is moisture – which is why reaching the ideal indoor humidity level is one of the easiest ways to suppress mold.

High humidity levels can contribute to the growth of mold in your home. When indoor air is humid, it means there is a high amount of water vapor, which can lead to mold and mildew contamination. Of course, this is a far bigger issue in certain areas with lots of rain – but you may be surprised to learn that all states have average humidity levels exceeding 71% throughout the year.

It is important to monitor these humidity levels and take steps to reduce them if they become too high. Prevention is the most important aspect of keeping mold at bay. But chances are you have some questions about this, like:

  • What are normal humidity levels?
  • What is a good indoor humidity level?
  • What causes high humidity levels inside a home?
  • How do I decrease the humidity in my home?

So, let’s dive in and discuss different ways to help you monitor and decrease humidity to achieve ideal indoor humidity in your home.

1. What You Need to Know About Indoor Humidity Levels

Indoor Humidity Levels

Indoor humidity levels are tricky because some moisture in the air is necessary for personal comfort and health. On the other hand, extremely dry air can cause health issues like asthma flare-ups, sore throat, eye irritation, nosebleeds, and dehydration. But on the other hand, high humidity not only helps mold grow, but it can also lead to poor indoor air quality.

Humidity causes common allergens to stay suspended in the air, such as pollen, dust, and, of course, mold spores. As a result, poor indoor air quality can lead to respiratory problems and issues for people with allergies.

What is the Recommended Humidity Level Inside a Home?

According to the Environmental Protection Agency (EPA), the ideal range of humidity levels is between 30% to 50%. However, if the humidity rises about 60%, then it is considered high and may lead to mold, mildew, and even invite in pests like cockroaches and dust mites!

How Do I Know if I Have High Indoor Humidity Levels?

There are several key signs which indicate you have higher than ideal indoor humidity levels. If you have noticed several of these signs repeatedly in your home, there is a very high chance that you have a humidity issue:

  • Foggy condensation on the windows
  • Mildew-like smell, especially on fabrics
  • Spots of mold growing on the walls
  • Materials like wood or stucco easily crumble
  • Paint chips off of the wall easily
  • Intense allergies
  • Excessive pests like dust mites or silverfish, a type of insect
  • Difficulty sleeping due to night sweats
  • Food left out goes bad quickly

Can You Test Your Home Humidity Levels?

Test Humidity With Hygrometer

Yes, you can test the humidity levels on your own fairly easily. A hygrometer is a device that measures the air’s temperature and humidity levels. You can usually find these in a home improvement store. This device will give you a fairly accurate reading of the humidity level, along with the range over the past 12 hours.

What Causes High Humidity Levels in a Home?

If you do have humidity levels that exceed 60%, you’ll want to figure out the cause for it. Unfortunately, some factors cannot be controlled, such as the climate and weather. If the humidity outdoors is extremely high, the indoor levels will grow as well.

Poor ventilation and the home’s construction can also lead to high humidity. If rooms are not well vented or sealed, air cannot move in and out of the home.

Some common everyday activities can also add more moisture to the air. For example, cooking, running appliances like dishwashers and laundry machines, and long, hot showers increase the amount of water vapor in the home.

Old HVAC units may also contribute to high humidity. These systems have evaporator coils inside, which pull humidity out of the air while it runs. If your system is not running at peak performance, it might cause high indoor humidity levels.

2. How to Decrease Humidity Levels in Your Home

Buy A Dehumidifier

Whether you have tested your indoor air humidity or you are concerned it’s too high, you should be proactive about the issue. Reaching the ideal indoor humidity range is easier than you may think!

Increase Ventilation

The most important thing to do to decrease humidity is to improve airflow throughout your home. This will help to disperse water vapor from areas of a higher concentration, such as the kitchen, bathroom, or laundry room.

Opening up windows and running fans is a quick solution, but this won’t necessarily help if the outdoor humidity is high. A good tip is to use properly vented exhaust fans while cooking, taking a shower, or running the dishwasher to reduce the moisture in the air.

Buy a Dehumidifier

The right dehumidifier can go a long way in preventing mold and mildew growth. Just make sure you purchase one that will cover the square footage necessary or get an adequate amount for every room of your home so it’s not too much hassle to keep up with!

Dry Up Wet Areas Immediately

While a water spill here and there won’t impact humidity much, leaving large damp spots to air dry can be an issue. If you are dealing with any flooding or large spills, dry up as much as you can immediately. You should also run fans on the area to dry it out completely. Mold spores can start to form in just 24 hours from water exposure, so you’ll want to take care of large spills right away.

Insulate Your Home Well

Basement Crawlspace Insulation

Insulation does more than just help you regulate the temperature in your home. It can also help to control humidity! So if you live in an older home or don’t have good insulation, this may be something worth investing in.

If you live in an area with heavy rain, you should be quite vigilant about keeping lower areas like the basement as dry as possible. Moisture from the ground can seep through into cellars and crawl spaces underneath your home. This damp environment makes basements and crawl spaces the perfect spot for mold to grow. Adding insulation to these rooms can help to keep exterior moisture from coming inside.

Take Care of Your Plumbing

Your pipes can also add moisture into the air, especially if they have leaks or cracks. Be sure to have your plumbing checked on a fairly frequent basis, especially if you notice signs of leaks like lower water pressure.

You should insulate your cold-water pipes, too, to help reduce condensation from forming.

Add Moisture-absorbing Items Into Your Home

This may sound odd, but having a bucket of charcoal in the house can help control humidity! Charcoal is highly absorbent and pulls moisture as well as musty odors from the air. You can just use the charcoal briquettes for the grill and place them inside a vented container (such as a coffee can with holes in the lid).

Put Your Plants and Wet Laundry Outside

While a few houseplants here and there shouldn’t cause humidity problems, too many can create a greenhouse effect. Many types of plants release moisture in the air, so you should either put them in a well-vented spot by an open window or move them outdoors.

The same goes for damp items like wet laundry. Line-drying clothes is a great way to cut down energy consumption, but it will increase indoor humidity. So take them outside to dry instead.

3. What if High Humidity Has Already Caused Mold to Grow in My House?

Mold Can Destroy Your Property

Common areas like bathrooms, kitchen sink cabinetry, and interior walls should be checked periodically for mold growth. And since mold likes to hide in dark, damp places, you should also take a look at your attic, crawl spaces, and basement for signs of mold growth.

If you find any dark spots or discover the unmistakable smell of mold or mildew, you’ll want to call in the experts right away. A thorough inspection should be conducted to determine where the mold is growing, how much is there, and the cause of its growth (i.e., moisture intrusion source).

From there, your mold removal team will begin the process of remediation. This involves killing all mold spores with cleaning solutions and removing any porous surfaces infested with mold, like carpets or flooring materials. In addition, the remediation process involves eliminating the moisture intrusion source that was feeding the mold in the first place – such as high indoor humidity levels!

Did High Humidity Cause Mold in Your Home?

Reaching ideal indoor humidity levels can help ward off mold growth, but it may be too late in some cases. If you’ve got mold growing in your home, GP Inspect can help. We offer mold testing, inspections, removal, and remediation services to Orange County, CA, homes.

Contact us today to learn more and schedule an initial inspection!

Publish on: Jul 24, 2018

Updated on: Dec 29, 2021

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Joseph Gutierrez

Mr. Gutierrez is a highly certified Environmental Hygienist and Property Inspector. He is well known and respected for his knowledge of the industry, work ethics, and superb customer service.