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If there’s a bad smell in your crawl space, you probably don’t really want to investigate further to determine the source. Unfortunately, an odor in your crawl space can affect the rest of your home: studies have shown that as much as half of your first-floor air comes from the crawl space. Finding out what’s causing crawl space odor is an important first step in fixing the problem. What could it be? There are several different possibilities to consider.

  • Maybe something is being stored in your crawl space that shouldn’t be. This is the least horrifying possibility, and also the easiest to remedy. Maybe the previous owners of the house left behind some trash, or maybe the contractors forgot about some old paint cans. Get rid of any junk that shouldn’t be in there.
  • Something may have died in your crawl space. Rodents, snakes, and other animals that like warm, damp places may look for shelter in your crawl space. While a crawl space is a good place to get out of the cold and rain, some of these animals will die while staying there. A dead and decaying rat or snake will certainly produce a foul odor!
  • Dead bodies aren’t all a rodent infestation leaves behind. Even if rats and mice aren’t dying in your crawl space, if they’re sheltering there they’ll leave behind droppings and urine. These can get into your air vent and are hazardous to your health.
  • A musty smell may indicate mold. Crawl spaces tend to have high moisture levels, and that attracts mold. The humidity levels can get particularly bad in crawl spaces with dirt floors, and the mold can get into wooden structures like floor joists. So, while the mold itself won’t always have a distinctive odor, the rotting wood that it creates will produce the nasty odor of mildew. Anything stored in a crawl space should be periodically inspected for mold; if you find any mold, call in a professional to remove it. Molds release mycotoxins, and these can be extremely harmful to your respiratory system.
  • Even without mold, moisture can create bad smells in your crawl space. When the concrete slab is poured, moisture can become trapped underneath if. Water vapor eventually finds its way through the slab, and bacteria that forms in the places the vapor collects can create an odor.
  • Earthen floors create their own problems. In addition to increasing moisture in the crawl space that attracts mold, the soil in an unsealed crawl space can contain organic matter like leaves and manure. When these things rot, they emit odors that eventually travel into the air ducts.
  • A sewage backup can fill your crawl space with a particularly vile odor. Sometimes, the main sewer line clogs. When this happens, water can back up in the pipe and leak into the crawl space. Not only does this smell terrible, but it can also lead to terrible damage, including damage to your home’s support posts. It can create mold growth, and can contaminate the soil, releasing toxic fumes that can make their way into your family’s living space. If you’ve got a sewage leak in your crawl space, call a professional disaster restoration company.

Once you’ve identified what’s making your crawl space smell bad, you may wonder how that smell is getting into the rest of your house. One way it happens is through what’s known as the stack effect, in which warm air rises, leaks from the upper levels, and pulls up new air to replace it. Some of this air comes from the crawl space, escaping through holes around wires and pipes and joints in the floorboards. A more direct route for crawl space air to enter your home is through leaky return ducts. When the ducts in the crawl space mingle the crawl space air with your upstairs air, that damp, smelly air can be released into the main floors of your home.

So, what can you do about odors in your crawl space? First, of course, you’ll want to eliminate the source, whether that’s some empty soda cans, a dead rat, or a patch of mold. Then look for solutions to the problem. Venting the crawl space is not helpful, because it lets in damp air that can result in mold growth. However, there are some tactics that can help.

  • You can get rid of crawl space smell using a dehumidifier. Using a dehumidifier will pull the moisture out of your crawl space air before it enters the rest of your home.
  • You can install a crawl space barrier to eliminate odors. This prevents ground moisture from evaporating into your crawl space, which reduces your risk of odors from moisture, mold, or pests. Designed to resist the flow of air, a crawl space foundation vapor barrier brings the temperature of your crawl space closer to the temperature in the rest of your home, and can even block the flow of harmful gases like radon. Contact a professional waterproofing company to install an effective crawl space barrier.

At Budget Waterproofing, we have more than 55 years of experience servicing both commercial and residential customers throughout Maryland. We’re proud of our craftsmanship and confident in our skills, and all of our technicians are fully licensed and insured. Whether you need basement waterproofing, a drainage system, crawl space waterproofing, or egress window installation, we’ve got you covered, with the experience and skills necessary to improve your basement and protect your family. For more information, contact us today.