5 Effective Tips To Reduce Humidity In Your Basement

Your basement feels muggy, has that unmistakable damp air, and yes, it's a bit on the stinky side. You might be asking yourself, "Why is this happening?"

Well, it's likely the humidity – something basements tend to attract. But don't worry, you're not the only one dealing with this. Basements are notorious for being humid, and there's a good reason why. 

In this blog, we'll dive into why basements become humid and share some tips on how to keep the humidity under control. Let's discuss.

The reason basements get humid

The soil surrounding your basement is a big reason you might have humidity problems.

Basements, by their very nature, are prime candidates for humidity problems. And there are a few reasons why.

1. Your basement is underground and surrounded by dirt, a notorious bad conductor of heat. Because of that, the basement is naturally cooler than the rest of your house. And sometimes, warm, moist air from outside or upstairs comes into your cool basement. When that happens, the moisture in the air cools down and turns into water droplets. This is why your basement might feel damp, or you might see water on the walls or pipes.
2. The soil around your basement can also hold a lot of water, especially when it rains a lot or when snow melts. This moisture can seep through the tiny cracks or concrete pores and add to the humidity in the air.
3. Basements don’t have a lot of windows or doors, and if they do, they’re not opened often. This means there isn’t a lot of fresh air moving through to help dry things out. It’d be like wearing wet clothes in a room with no breeze – it takes longer to dry.
4. Appliances like washing machines, dryers, and showers in your basement can contribute to humidity, too. Washing clothes or taking a hot shower produces a lot of steam, which adds more moisture to the air.

All in all, your basement gets humid because it’s cool and doesn’t get much fresh air, it absorbs moisture from the wet ground around it, and appliances common in basements only add to the moisture in the air. These factors are a perfect storm for a damp, musty basement. 

The science behind humidity

I know we're all familiar with humidity, especially if you've ever been on a vacation to Florida. But let's break down the basics.

Humidity simply means the amount of water vapor in the air. A common term when talking about humidity is "relative humidity" or RH for short. This is the percentage of water vapor in the air relative to the maximum it can hold at that temperature. If the air has taken in all the water it can, it's at 100% RH – that's when it feels really humid to us. 

The warmer the temperature, the more water vapor it can hold.

The temperature of the air matters a lot because warm air can hold more water than cold air. This is why humidity is not solely confined to warm environments but is a significant concern in cooler, underground spaces like basements. The air down there can still hold water, and when it gets too full, things feel damp and muggy.

How to know if your basement is too humid

Detecting high humidity in your basement early can save you a lot of trouble down the road. It’s not just about the discomfort; excessive moisture can lead to bigger issues like damage to your home and health problems for your family.

But how do you know if your basement is too humid? Let’s break it down into simple signs you can look out for.

What is a good humidity for a basement?

You want your basement humidity to be between 30 to 50% RH.

So, what’s the magic number? For basements, you’re aiming for a relative humidity (RH) between 30% and 50%.

Staying within this range helps keep mold at bay, protects your belongings from moisture damage, and makes the air feel more comfortable. Once it gets above 50%, the moisture in the air allows indoor allergens to survive and thrive.

How to measure your basement's humidity

If you want to measure the humidity levels in your basement, you can use a hygrometer. A hygrometer is a device that measures the amount of water vapor in the air.

It’s pretty straightforward to use. You place it in your basement, and it gives you a reading of the humidity level, usually shown as a percentage. This percentage is what we call relative humidity (RH), which tells you exactly how much water vapor is in the air compared to how much it could hold at that temperature.

3 simple ways to keep basement humidity low

If you're dealing with high humidity, don't worry just yet. There are several steps you can take to control the humidity in your basement.

1. Improve ventilation

This is my depiction of the moisture trapped in your basement. These little guys don't want to be there just as much as you don't.

You know when you're closing a Ziploc bag, and the air gets trapped in there? Your basement is kind of like that with moisture. If you don’t have a good ventilation system, moisture will stay trapped in your basement.

Ideally, you want air to move freely in and out of the space. Here’s how:

1. Open windows. Whenever the weather outside is drier than inside, open the basement windows (if you can) to let fresh air in.
2. Use fans. Placing fans strategically can help circulate air and move moisture out.
3. Vent appliances outside. Make sure that dryers, stoves, or any other appliance that produces moisture vents outside and not into your basement.
4. Invest in an air purifier. Air purifiers suck out all the bad stuff in the air, including dust, pollen, pet dander, and smoke particles, then filter that air to recirculate it back into the room. They improve the air quality, reduce mold growth, and alleviate allergy symptoms.

2. Seal leaks and cracks

Water has a sneaky way of finding its way into your basement through the tiniest of gaps. Here’s what you can do:

1. Inspect regularly. Check your basement walls and floor regularly for any signs of cracks or leaks.
2. Use sealant. Apply a waterproof sealant to any cracks you find. You might need to patch larger gaps.
3. Consider professional help: If you’re dealing with significant moisture, it might be time to call the pros for a more thorough waterproofing solution. And hey, just so you know, we're those pros (yep, the ones you should be calling).

3. Maintain gutters and downspouts

These clogged gutters are troublemakers—they block water flow, causing it to overflow and spill right next to your foundation, leading to basement humidity and moisture issues..

Your gutters and downspouts direct rainwater away from your home’s foundation. If they’re clogged or damaged, water can pool around your house, increasing the risk of it seeping into your basement. Here’s how to keep them in check:

1. Clean regularly
2. Check for damage
3. Extend downspouts

If you're like most people and dread cleaning your gutters, consider getting gutter guards or a seamless gutter system. These block leaves and debris, ensuring no clogs... ever. It's a hassle-free solution we highly recommend.

If you need more advanced humidity control...

While simple solutions like opening windows and using fans can work, sometimes you might have to take more extreme measures with an advanced humidity control plan. Here are a few strategies you can adopt to reduce the humidity in your basement.

Invest in a dehumidifier.

A dehumidifier sucks in damp air, removes the moisture, and blows back drier air. 

P.S. We like to share unbiased information in these articles without pushing our products too much. However, we must mention the SaniDry Sedona, the world's most efficient dehumidifier and filtration system we install. It's a game-changer for removing those damp, musty odors in your basement.

There it is... a beautiful dehumidifier. And not just any dehumidifier—it's the SaniDry Sedona. Isn't she a beauty?

Here's the thing: Not all dehumidifiers are created equal, and choosing the right one is crucial.

1. Types: There are two main types of dehumidifiers: refrigerant and desiccant. The refrigerant works like… you guessed it.. a refrigerator, and the desiccant uses absorbent material to remove moisture. Desiccants are ideal for extremely humid environments and work really well in cold basements, whereas refrigerants are more common and affordable.
2. Sizing: The size you need depends on your basement’s square footage and dampness. Look for a unit rated for your space size and conditions (i.e., slightly damp, very damp, wet).
3. Placement: For best results, place your dehumidifier in the center of the basement or the most humid area. Make sure there’s proper airflow by leaving at least 12 inches of space around the unit.

Basement waterproofing and foundation repairs

Look... as a basement and foundation contractor, of course, we're going to recommend waterproofing and fixing foundation issues. 

But in all seriousness, if the above tips aren't working, you might need to take these extra steps to keep moisture out, especially if your basement has structural issues that let water in. 

Behold... a stunning waterproofed basement with no humidity in sight (Okay, so you can't exactly see humidity, but you get the idea).

1. Interior waterproofing: This involves several methods, from applying a waterproof vapor barrier on interior walls to installing systems like sump pumps or French drains to help manage water that collects around or under your basement. Waterproofing keeps water out, so humidity never has a chance to rise.
2. Exterior waterproofing: This is more involved and can include excavating around the house to apply a waterproof membrane outside the basement walls (Spoiler alert: We explain why we're not big fans of this solution here).
3. Foundation repair: Cracks or gaps in your foundation can be entryways for moisture. Repairing these issues not only prevents water from entering but also strengthens your home's structural integrity.

For these repairs, we recommend calling in a pro... and by a pro, we obviously mean us.

In the video below, Shane McClintic, our basement repair expert with over a decade of experience, shares insights on maintaining healthy basement humidity levels. He covers signs of excessive humidity and its potential health risks, such as mold, dust mites, and allergies.

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When to seek professional help

Like many homeowners, we understand that calling in a professional isn't always the first step. We've been there, delaying a repair or two (okay, maybe three) in our own homes. We get it.

There are certain signs that indicate your humidity issue might be beyond a DIY fix. This includes: 

1. Persistent mold growth: If you've tried everything and still have mold, the issue could be more serious than you think.
2. Structural damage: Signs of water damage to your home's foundation or structural beams are serious and require immediate attention.
3. Water infiltration: Regular pooling or flooding in your basement, even after minor rains, suggests a significant waterproofing issue.

And hey, nice to meet you! We didn't introduce ourselves earlier, but we're Thrasher Foundation Repair, a foundation and basement contractor with almost 50 years of experience. When it comes to foundations and basements, we know what to do.

If you happen to live in or around Omaha, Kansas City, Wichita, Denver, Springfield, Grand Island, Sioux City, or Peoria, we're here to help with any basement questions, humidity issues, or hey, even just chatting about life – we’re up for that, too. You can reach out to us by calling us at 1-800-827-0702, filling out this form, or starting a chat in the bottom right-hand corner.