3 Signs of a Damp Crawl Space

Never go in your crawl space? That’s ok, there are signs to look for in the living space that may indicate a damp crawl space. Many of these signs are visible. While others may require your nose. Even others could use a humidity reader or moisture meter to detect.

Trust me, those meters are worth the investment. Or perhaps you can get someone like us to check out the crawl space for you. Either way, don’t ignore these signs that you have a wet crawl space. Ignorance is not bliss, but may lead to poor indoor air quality when it comes to ignoring your crawl space moisture issues.

1. Damp Crawl Space Sign – Odors

That’s right, smells may be the best indication of a damp crawl space. The problem is, you are probably used to how your home smells. Because of this, pay attention to when your mother-in-law decides to visit and overshares about how your house stinks, among other things. Getting cues from loved ones, friends and neighbors about odors in your home may be a sign you have a damp crawl space. Here are some terms to listen for:

“It smells like a basement in here.”

“What is that dirt smell?”

“Have you noticed a musty smell when the heat turns on?”

“When I go to work, someone told me my clothes smelled like mold.”

After the shock of just how rude some people can be has passed, try to look for other signs in the living space that may confirm you have a damp crawl space.

2. Cupping Hardwood Floors

If you have hardwood floors and notice the edges are raised a bit or a lot, this is called cupping. According to Bona.com,

“Hardwood floor cupping is caused by a moisture imbalance in the flooring. It is a condition when a wood floor gains more moisture on the underside of the board, causing the boards to swell on one side, giving the outside edges of the plank a raised look while the center remains flat.”

Did you notice “when a wood floor gains moisture on the UNDERSIDE?” The underside is the subfloor. The subfloor is located in the crawl space. Chances are, if your hardwood is cupping, you have a damp crawl space. This could be from high humidity, a plumbing leak or insulation trapping moisture against the subfloor.

Many homeowners are so used to their hardwood cupping they say things like, “Yes, the hardwood does that every year but eventually goes back to normal.” The problem with this philosophy of hardwood self correction is chances are mold is growing in the crawl space. Mold in the crawl space causes odors that lead to oversharing from friends and family.

3. High Humidity from HVAC

Damp crawl space sign #1, odors, requires a good smeller. Damp crawl space sign #2, cupping hardwood, can be seen and felt. But damp sign #3 of crawl space moisture may be a little more difficult to notice without moisture meters.

If your HVAC ductwork travels through the crawl space, typically it will pick up humidity. As the air blows into the registers, it can release that high humidity into your living space. Most properly functioning HVAC systems with a dry crawl space will average humidity levels around 45% or lower.

An improperly functioning HVAC system and/or damp crawl space can blow humidity levels well above 60%. Over 60% humidity can allow mold to grow. Sometimes the crawl space can be dry, and the HVAC requires maintenance. An HVAC system that is not draining properly will blow out high humidity. Using a relative humidity meter is a great way to catch this issue. Just place the meter over a register while the fan or compressor are running. A visual sigh could be rusty registers or dark old spots on baseboards or walls around the register.

Contact Crawl Space Ninja for Basement Waterproofing and Encapsulation

Please contact us to schedule your assessment to fix your crawl space, basement issue. 


Do you need help with mold removal, crawl space encapsulation, crawl space insulation, vapor barrier, waterproofing, foundation repair, basement waterproofing, or controlling humidity in your crawl space?

If you live in Georgia, Delaware, North Carolina, South Carolina, Tennessee, or Kentucky, Crawl Space Ninja can help!


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