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Musty Smells in House

When you’re dealing with musty smells in your home but can’t figure out where they are coming from, call the experts.

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Smell something musty or stinky in your house, but just can’t figure out where it’s coming from? The source could be below your feet, in the crawl space. Learn how nasty crawl space smells get into your home, and how experts at Peak Structural can help you get rid of them.

What Causes the Smell?


Even though the climate is dry, your crawl space will lock in any kind of moisture. If you have water intrusion in your crawl space—from the occasional rain or from sprinklers in your yard—the moisture and humidity building up will eventually sprout mold. Since mold is airborne, it will grow freely in the dark, damp environment. Particularly during sweltering hot summers, mold and humidity creates the perfect thriving ground for stinky smells.


Pests are attracted to moisture and darkness as sources for survival and nourishment. Especially during the dry summers in Denver, Pikes Peak, and Colorado Springs, pests will take shelter within your crawl space. Common crawl space pests like rats, mice, opossums, raccoons, snakes, chipmunks, roaches, spiders, and termites sneak into your crawl space and leave behind nasty smells, debris, and even carcasses.

spiders in crawl space

Burst Pipes or Sewage Breaks in Your Crawl Space

Many homes use the crawl space to weave ductwork below the home to “safely” conceal it. You’ll run into issues when you experience a sewage clog or burst, you could have a crawl space flooded with waste. You may not realize it right away until the scent gets overwhelming. If this happens, call an emergency plumber right away.

How Does It Get in My Home?

Stack Effect

It’s commonly known that hot air rises and cool air sinks. This phenomenon can take place in your crawl space, and when referring to homes, it’s called the stack effect. This means that all that nasty, smelly, and moist air in your crawl space will rise through your home and out through your roof. 

Up to 50% of the air in your home comes from the crawl space—so when you’re dealing with musty smells coming from mold, waste, and pests, you can smell it and breathe it all in.

Ductwork Located in Your Crawl Space

Having airducts or pipes in an unprotected crawl space is a risky practice—especially if pests have invaded. Bugs or animals can gnaw at air ducts, creating openings for nasty smells to flow into your home easier.


Not always, but if you’ve looked around and can’t find any detectable source, mold could be the cause. Mold in your crawl space could emit a smell, but that’s not the only symptom. If you also notice an uptick in your allergy symptoms, or asthma, you could be dealing with crawl space mold. 

If you suspect mold in your crawl space, don’t go down there to inspect it yourself. At Peak Structural, we provide free inspections of your crawl space, and will let you know what’s wrong. Our inspectors have safety equipment and training to inspect crawl spaces for mold, pests, and more.

From the 1960s to the 1990s, it was commonly believed that constructing crawl spaces with vents or openings would ventilate or “air out” the area. In reality, the installation of a crawl space entry point invites and locks in moisture, pests, and mold. 

Instead of leaving a crawl space vent open, encapsulate the crawl space and install a crawl space door or vent cover. This will ensure that excess moisture doesn’t get in your crawl space, and the environment in your crawl space remains cool and dry.

Insulating your crawl space primarily helps with temperature regulation and energy efficiency. Chances are if you’re experiencing excess humidity and mold in your crawl space, extreme temperatures could be creeping in as well. Along with installing a vapor barrier and humidifier, crawl space insulation will help control the source of unhealthy air in your home.

If you’re dealing with nasty smells, pests, excess moisture, and more, a crawl space dehumidifier will do wonders for your home and potentially your health. Regulating humidity in your crawl space will help tamp down on moisture, mold, pests, and musty smells—but it should be paired with other crawl space encapsulation elements like vapor barriers, crawl space vent covers, insulation, and more.

Call Us for a Free Inspection

Peak Structural has been taking care of smelly crawl spaces in Colorado for 20 years—we understand how stressful and even embarrassing it is to be dealing with smells in your home. We want to make it easy for you to figure out what’s going on, that’s why you’ll get a free inspection of your home if you contact us. Our crawl space experts will inspect your home and let you know exactly what’s going on. Then, we’ll give you a no-obligation, transparent quote. 

Getting started with Peak Structural is easy. Contact our team today!

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Colorado Springs Office

707 County Line Rd.
Palmer Lake, CO 80133

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4686 Ivy St
Denver, CO 80216

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2575 U.S. 6 & 50, Unit A, Grand Junction, CO 81501