Curious about the ideal basement humidity? If so, this short article will provide valuable information about the ideal basement humidity, why basements get humid, and how to keep them comfortable and dry.
Basements are humid because they’re underground and surrounded by soil. Because they’re often humid, they’re an excellent place for mold and mildew to thrive. Mold and mildew can damage anything stored in a basement, and some of the moldy air in your home’s basement goes into the upstairs living area. It smells bad and can cause health problems because it’s full of allergens.
Of course, if you want to use your basement as a living area, you’ll need to keep the humidity level down because nobody wants to spend time in a damp environment. Fortunately, basements don’t have to be damp.
Ideal basement humidity level for comfort
If you want to be comfortable, the ideal basement humidity level should be between 30-50%. Once the humidity goes over 50%, there’s a risk of mold growth. If the humidity level falls below 30%, the air gets dry, and uncomfortable and could cause nose bleeds and dry skin.
Why are basements humid?
Basements are humid because:
- They’re surrounded by dirt.
- If it’s a poured concrete foundation, the walls might have hairline shrinkage cracks (caused during the concrete curing process) that allow moisture into the basement.
- If there’s a laundry in the basement, the exhaust vent could have malfunctioned.
- There’s excess water in the soil around the foundation. (We’re going to talk more about this in a bit, including what you can do to make sure excess water isn’t able to build up in the soil around your home’s foundation.)
- Your pipes are leaking.
Signs of excess basement humidity
You probably won’t see puddles of water on your basement floor. However, that doesn’t mean you have a dry basement. Signs indicating excess humidity in your basement include:
- Water stains – The water stains may be on walls, floors, or something else in your basement.
- Condensation on walls – Run your hand over the walls. Do you feel any moisture? If so, that’s condensation and a sign of less-than-ideal basement humidity.
- Water running down walls – An obvious sign of a problem.
- Condensation on windows
- Mold and mildew – This could be on the walls, furniture, structural elements, carpet, etc.
- Bad smell
- Spalling on concrete – Spalling happens when water trapped in the concrete goes through freeze-thaw cycles. Eventually, the concrete starts to break down, and pieces of it start to flake off.
If you don’t see anything wrong, you can still check the humidity level in your basement using a decent moisture detector.
For more information, see A Quick Guide To French Drain Basement Waterproofing.
How to maintain ideal basement humidity
You need to keep moisture out of your basement if you want ideal basement humidity. However, simply putting up a barrier to stop moisture from entering the basement isn’t enough. It might work temporarily, but it’s not a long-term solution.
The best way to achieve and maintain ideal basement humidity is to control groundwater around the foundation. Good drainage ensures that excess moisture can’t build up in the soil around and under the foundation. If there’s no excess moisture in the soil, it can’t get into your basement. Problem solved!
Here are some ways to get excess water around and under your home’s foundation under control:
- Make sure your yard is graded correctly – The yard around your home should slope away from the foundation. If it doesn’t, water could drain toward the house, pool around the foundation, and cause trouble. A landscaper or foundation repair contractor can help with yard regarding or, you could do it yourself.
- Clean your gutters regularly – Clogged gutters could allow water to spill over the side of the house and into the ground next to the foundation. From there, it could find a way into your basement.
- Install downspout extensions, if necessary – Sometimes downspouts are too short and release water next to the foundation. Downspout extensions are inexpensive, quick to install, and will channel water away from your home’s foundation before releasing it.
- Don’t plant water-hungry vegetation near the foundation – When you water them, you’ll just be adding more water to the soil.
- Make sure you don’t have any leaking pipes – These could be water or sewer pipes.
The above are excellent and relatively inexpensive ways to prevent excess water from building up around a foundation. However, a drain tile system is a gold standard for basement waterproofing and achieving ideal basement humidity.
How does a drain tile system work?
A drain tile system (also sometimes referred to as a “French drain”) prevents excess water from building up in the soil around the foundation by channeling it into a sump pit and then releasing it away from the foundation, either via gravity or a sump pump. There are two types of drain tile systems: exterior and interior.
Exterior drain tile system
An exterior drain tile system is installed around the perimeter of the foundation at the footing level. A shallow trench is dug, and a perforated pipe is added. Any excess water in the soil flows into the pipe and gets channeled into the sump pit. The water is released from the foundation via gravity if yard grading permits. Otherwise, a sump pump gets rid of it.
Exterior drain tile systems are easy to install during construction. However, they can be installed in existing homes as well. It’s not a DIY project though because installing an exterior drain tile system in an existing home requires excavation down to the footer.
Interior drain tile system
An interior drain tile system is installed inside the basement, collects excess water in the soil under the slab, and directs it into a sump pit. A sump pump then ejects the water away from the foundation.
Installing an interior drain tile system involves breaking up the slab. Therefore, it’s a major construction project.
For more information about drain tile, see How Does A Drain Tile System Work?
There are various ways to prevent moisture from entering your home’s basement. However, if you want a long-term solution – along with ideal basement humidity – you’ll need to prevent water build-up in the soil around the foundation, and the best way to do this is via a drain tile system.