Why Does My Crawl Space Smell Musty? (5 Causes)

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What an annoying experience it is when your crawl space develops a musty odor that ends up in your house.

Even worse, this unpleasant smell is usually accompanied by germs that can pose a health risk to family members.

If you’re among the many people wondering “Why does my crawl space smell musty?” This post will provide you with the answer. More importantly, we’ll provide you with the needed solutions to overcome this problem.

Why Does My Crawl Space Smell Musty?

Multiple causes can contribute to the unpleasant odors in your crawl space. Nonetheless, the following are the five most common reasons for this issue:

1 – Mold Spread

Mildew and mold can develop in your crawl space regardless of its cleanliness.

The ideal conditions for mold growth include a temperature of above 65°F and a humidity level of at least 60%.

These conditions can easily be present in your crawl space. Once this happens, mold starts to grow exponentially within a few hours.

The mold itself doesn’t have a nasty odor. However, as it spreads, mold comes into contact with other objects, such as wooden structures.

As a result, the affected objects emit an unpleasant musty odor.

2 – Moist Fiberglass

The odor problem might be due to the interaction of fiberglass with humidity.

Fiberglass is highly likely to soak up moisture. When it’s exposed to humidity, it produces a rotten sulfuric odor.

3 – Dead Rodents

Any dark place full of debris and fiberglass can be an attractive destination for rodents. This is exactly what most crawl spaces look like.

In this case, these animals live, leave waste and die inside your crawl space. As a result, the crawl space can turn into a messy spot with a musty odor.

4 – Sewage Leaks

There might be a sewage leak in the crawl space that you haven’t noticed if you only use the place occasionally.

This sewage leak could be the primary source of the nasty smell present in your house.

5 – Breakdown of Soil Microbes

Some homeowners describe the smell of their crawl spaces as similar to cat urine. The cause of this odor is the breakdown of microbes in the soil within the space.

This process results in the production of ammonia. The higher the pH of the soil, the more intense the odor will be.

How to Get Rid of the Musty Smell of Crawl Space

The key to removing the musty smell in your crawl space is to clean it and keep it dry.

There are many ways to achieve this. Some of which you can do yourself, while others require the help of professionals.

Here are the most effective solutions to consider:

Clean the Space

Debris, fiberglass, damaged wood, and dirty items in your crawl space are key contributors to the nasty smells.

That way, you need to regularly clean the space by removing these objects. You can do that yourself or with the help of a professional crawl space cleaner.

Seal the Area

Vents in your crawl space can bring excessive moisture into it. They can also provide access for rodents and other animals into the area.

To avoid these two problems, you need to seal your crawl space vents. Ensure it’s a perfectly enclosed environment.

Decrease Humidity Level

You can control and prevent mold growth by decreasing the humidity level in your crawl space to below 60%. To do this, you’ll need to use a dehumidifier.

Look for a dehumidifier that is low-maintenance and self-draining. In addition, choose one that is specifically designed for crawl spaces. That’s because some traditional household dehumidifiers may not effectively reduce humidity in crawl spaces.

Install a New Vapor Barrier

Consider installing a new vapor barrier to prevent unwanted moisture from entering your crawl space. Installing a vapor barrier on the walls and floor will keep moisture away from the place.

Contact a Professional

If a sewage leak is the cause of the unpleasant odor, contact a professional plumber to help fix it.

Likewise, if the smell comes from the structure’s wood rot, consider contacting your crawl space contractor to help you solve the problem.

What to Put in the Crawl Space for a Musty Smell

In addition to dehumidifiers, the following items can considerably speed up the process of removing musty odor from the crawl space:

• Baking soda: Baking soda can eliminate contaminants caused by mold. It can also provide a clean, fresh scent in the crawl space.
• Volcanic rocks: These rocks can absorb smells and significantly reduce their intensity in your crawl space.
• Activated charcoal: Charcoal is highly effective in absorbing and trapping odors inside.
• White vinegar: Place a few large bowls of undiluted distilled white vinegar in the area. This substance has high efficacy in eliminating unpleasant odors.

Final Thoughts

By now, you know the answer to” Why does my crawl space smell musty?”

Your crawl space can smell musty due to various reasons. The spread of mold all around the place may cause this unpleasant smell. Dead rodents and sewage leaks also can be responsible for this issue.

Additionally, when moisture interacts with fiberglass in your crawl space, this can result in a foul smell. Further, the breakdown of microbes in the soil of the crawl space can contribute to this problem.

In any case, following the provided solutions can effectively eliminate the musty smell in your crawl space.

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