Pros Say This Is the Best Humidity Level for a Comfortable Basement
EyeWolf / Getty Images
Humid basements can start to feel muggy, damp, and uncomfortable, while basements with very low humidity levels feel dry and stifling. Use this guide to find out what the ideal basement humidity level is and how to measure basement humidity.
How to Measure the Basement Humidity Level
Hygrometers are designed to measure the humidity level in the air and provide accurate readings. Hygrometers are relatively inexpensive, so if the basement regularly has humidity problems, consider purchasing several and have them mounted or otherwise positioned around the basement.
If humidity problems go unresolved it can lead to mold growth, peeling wallpaper, bubbling paint, rusting pipes, and more. Invest in a hygrometer to find out if there is a problem before serious signs appear.
Causes of Basement Humidity
Basements are more prone to humidity problems than other areas of the house because they are below ground and surrounded by soil. There is a higher chance that moisture can seep into the space through cracks in the foundation walls or as a result of improper drainage around the foundation.
Similarly, activities that release moisture into the air will increase the ambient humidity levels, such as cooking, showering, or doing laundry. If this humid air is not properly ventilated, then it can cause the basement humidity to increase beyond comfortable levels. Moisture may also seep into the basement from new concrete foundations as the concrete gradually dries in new homes.
Opening a basement window can increase or decrease the humidity levels, depending on the time of the year and the humidity outside. Other sources of basement humidity can include leaking water pipes, dripping faucets, cracked drainage pipes, exposed dirt floors, and poor ventilation.
Why Is Basement Humidity a Problem?
High basement humidity can cause musty odors, mold growth, wood rot, rusting, and moisture accumulation. Many pest species prefer a warm, humid environment to nest and reproduce, so having high humidity can increase the risk of pest infestations.
When the humidity is too low, it can dry out the structural material, causing cracks in wood and creating gaps in the windows and doors. Keep an eye out for any of the following signs that your basement may have humidity problems:
Water is coming through one or more foundation walls due to cracks in the concrete, poor drainage, or a build-up of hydrostatic pressure.
The basement walls are damp or wet to the touch.
There is standing water in the basement.
The base of the walls are damp.
The basement feels muggy or stifling.
Condensation forms on the basement walls, floor, and other cool surfaces during the summer.
There is a musty smell in the basement.
Carpet or wood structures in the basement are moldy or rotting.
Wood structures are dry and cracked.
Paint is bubbling or peeling.
Wallpaper is peeling.
Efflorescence from salt deposits is left behind on the walls or floors. It has a chalky appearance.
There are water stains on the walls or floor.
Recommended Basement Humidity Level
Typically, the basement humidity level should fall between 30% to 50% to ensure that the space is comfortable and that the amount of moisture in the air helps to maintain the existing conditions of the home.
When moisture levels fall below 30 percent, the air becomes too dry, causing wood to crack and gaps to appear in window frames or door frames. When the ambient humidity is above 50 percent, the air will feel thick and muggy.
Condensation can form on water lines, refrigerators, concrete floors, and other cool surfaces, creating idea conditions for mold, mildew, and bacteria growth. The humidity level will vary depending on where you live, the average humidity outdoors, and the current season.
Ideal Basement Humidity Level in Summer
Ideally, the house should be kept between 40% to 50% during the summer season. This is enough to ensure the safety of the structure without creating such a significant difference between the outside humidity and indoor humidity that it become uncomfortable moving from one to the other. Attempting to force the indoor humidity levels too low during the summer can increase heating and cooling bills as the dehumidifier attempts to keep up with demands.
Ideal Basement Humidity Level in Winter
When winter season hits, humidity levels outside the home drop, so you can set the dehumidifier to between 30% to 40% for the duration of the winter season. Just keep in mind that the air can dry out quickly when heating the home. It's a good idea to check the humidity levels inside the house at least once a week to ensure that the air isn't too dry. If the air is too dry, you can use a humidifier to increase the humidity in the basement.
How to Control Basement Humidity
To control basement humidity, start by using a hygrometer to check the ambient humidity levels in the basement to determine if there is a humidity problem and whether the humidity level needs to be increased or decreased.
How to Increase the Basement Humidity Level
The basement humidity level may get too low in the winter when the furnace, radiators, or baseboard heaters are working to heat the interior of the home. Similarly, the basement humidity levels may be low if you live in a dry location with low outdoor humidity levels. Use these methods to increase the basement humidity levels.
Invest in a humidifier to add moisture to the air.
Boil water on the stove.
Keep the door opened a crack to release moisture from the shower or bath.
Turn off the dehumidifier.
Purchase plants for indoors.
Hang-dry laundry inside.
Open the dishwasher before the dry cycle.
Use a water-based oil diffuser.
Open windows if it is more humid outdoors.
Close windows if it is less humid outdoors.
Upgrade doors, windows, and weatherstripping.
Don't drain the bathwater until it has completely cooled.
How to Decrease the Basement Humidity Level
High humidity is usually a more common issue for basement than low humidity. Moisture can seep in through the foundation or even up through the ground if the basement has a dirt floor, so it's important to take steps to decrease the basement humidity when the moisture levels are too high. Try one of these methods to decrease the basement humidity level.
Fix cracked or leaking drain lines, water lines, and plumbing fixtures.
Put a plastic barrier over dirt floors.
Repair or adjust the butters and downspout system for better drainage.
Ensure water-using appliances are properly vented to the outside.
Ventilate bathrooms and kitchens.
Open the windows if it is less humid outdoors.
Close the windows if it is more humid outdoors
Insulate the walls, ceiling, doors, and windows.
Increase air circulation throughout the home.
Regrade the yard to prevent water from flows toward the house.
Avoid planting water-hungry vegetation next to the house.
Frequently Asked Questions
Is 60% humidity too high for a basement?
The ideal basement humidity level falls between 30% to 50%, so if the current humidity level is over 50%, then the humidity is too high. Use a dehumidifier to help reduce the basement humidity level until it is within a normal range.
What should I set my basement dehumidifier at?
During the summer, it's recommended to set the basement dehumidifier between 40% and 50%. In the winter, set the basement dehumidifier to between 30% to 40%.
Should you run a dehumidifier in the basement all of the time?
The dehumidifier should not need to run constantly to control the humidity levels in the basement. Generally, it will take about eight to 12 hours for the dehumidifier to reach the ideal humidity setting, then it should shut off. If the dehumidifier continues to operate, then there may be a serious moisture problem in the basement or the dehumidifier may need repair.
Read Next: How to Conduct a Simple Moisture Test on Concrete Floors
Read the original article on The Spruce.
