What Should the Humidity Level be in Your Basement?

basement humidity level

Whether you want to create a workshop, storage space, or even an extra living area, the basement of your building is the first thing that comes to your mind. However, if you want to put your basement area to good use, maintaining a proper humidity level is crucial.

It’s not that difficult. Anything that goes out of proportion is harmful, and the same goes for your basement humidity levels. You don’t want them too low or too high. But, what is the ideal humidity level for the basement? We’ve compiled all the details right here to ease the ordeal for you.

The Ideal Humidity in a Basement

Let’s start by clarifying how much humidity should be there in your basement. You see, both high and low humidity levels can cause dire consequences that make your basement less comfortable for its occupants.

Besides that, the humidity levels affect the well-being of the structure as well. So what’s considered ‘normal’ when we talk about humidity levels for a basement?

Well, the average level of humidity should be anywhere between 40 – 65 percent depending on the climate, weather, and other amenities in the basement.

High Humidity Levels

Anything above 65 percent of moisture in the air is considered a high humidity level. Excess humidity in the basement can be caused by various reasons. These include:

  • Leaking exhaust vents
  • Malfunctioning sump pumps
  • Out of order gutter spouts and water accumulation
  • Incompetent insulation
  • Vast different between indoor and outdoor temperature

Mainly, any aspect that creates highly damp conditions inside your basement causes excess humidity. If left untreated, high humidity levels can be scary. The effects of high moisture are:

  • Production of mold, which can disintegrate concrete and wall paint
  • Accumulation of mildew
  • Increased fungal growth, which can cause breathing problems for inhabitants
  • Creature favorable conditions for termite breeding. This can damage your furniture and other artifacts stored inside the basement.

Low Humidity Levels

On the other hand, low humidity levels are no less harmful to your basement environment. Low humidity basically means that there’s a severe lack of moisture in the air inside. Low moisture is anything less than 40 percent humidity in the air.

There are various factors that cause a drop in humidity levels inside your basement. Some of these reasons are:

  • Drastically high temperature
  • No temperature regulation system
  • Excessive air conditioning

These factors cause excessive dryness in the air, which can not only harm the building but cause fatal health issues as well. The most concerning effects of low humidity are:

  • Respiratory problems such as sinus, dry cough, cold, flu, and even asthma
  • Skin chapping and dryness
  • Dry scalp, excessive dandruff, and psoriasis
  • Paint peeling off
  • Air conditioner malfunction

Now that you know that both high and low humidity levels can create unfavorable conditions inside your basement, you’ll need to know how to prevent both conditions.

But, before that, you should know the thresholds for high and low humidity in different seasons so you can determine the relative humidity in your basement.

Right Basement Humidity Level in Summer

The ideal humidity level for the basement in summers is 50 percent. However, it depends entirely on your location and climate. The humidity level is directly proportional to the temperature. This means, the higher the temperature inside, the higher your humidity level goes.

If you live in areas where summers are hot and dry, your humidity levels may get low as well. Whereas in wet areas where summers are accompanied by wet monsoons, the humidity may go higher than average.

That’s why it’s essential to stay inside the 50 percent threshold. Below that will become too dry for summers, and you may experience skin discomfort and dry cough. On the contrary, higher than 50% may result in mold and mildew production.

Remember, reaching 50% during summers is difficult. You can use ventilation, insulation, or even dehumidifiers. The trick is to regulate the temperature in your basement, and you’ll be able to entirely control humidity.

See Related: Basement Ventilation Guide

Best Basement Humidity Level in Winter

In winter, any finished basement is likely to dry out. Following this, the relative humidity may fall below 50%. In this case, the ideal humidity level for your basement depends on the temperature outside.

For instance, if you live in cold areas where the temperature remains within zero degrees, you should go for 30 to 50 percent humidity inside your basement. On the other hand, in the case of highly frigid areas where the temperature drops below zero degrees, your basement humidity should be 20 to 30 percent.

That’s because, in icy conditions, high humidity may lead to ice formation inside your basement window sills and ventilation ducts. This, in turn, will cause a nuisance and damage your structure as well.

In this case, a dehumidifier can help regulate the levels inside. Besides that, you can use exhaust fans when conducting activities like drying clothes, mopping the floors, or showering.

Basement Humidity Level Control

There are many significant factors that may alert you if your humidity levels go against the norm. These factors include:

  • The appearance of mold and mildew
  • Rusty appliances and fittings
  • Hygrometer readings
  • Stuffiness and difficulty in breathing

If you face or witness any of these, it means your basement condition needs intervention. One of the best ways to do that is by installing a dehumidifier in the basement.

There are many types of dehumidifiers, mainly Whole Home and space dehumidifiers. The former is adjusted into your HVAC system to regulate the entire home, while you can use the latter to target your basement only.

Unless you’re facing an uncontrollable humidity situation, there are other ways apart from expensive dehumidifiers to do the job for you. Namely, HVAC fans, air conditioning systems, and vent fans work great as well.

Most importantly, make sure to get reliable insulation services and get your floors and walls for any leakages as a preventive measure.

Final Words

That wraps up our guide for keeping your basement safe against high and low humidity levels. Let’s face it; every finished basement can become subject to fluctuating humidity unless precautions and preventive measures are taken.

High humidity levels bring mold, mildew, and termites, while low humidity brings paint degradation, rust, and respiratory problems.

Needless to say, no situation is better than the other. The only way is to regulate the moisture to an ideal level according to the season to make sure you can have a comfortable environment all year long. Use a hygrometer to assess the humidity levels and take the necessary precautions to maintain them before they get out of hand.