How to Fix Moisture in a Crawl Space

How to Fix Moisture in a Crawl Space
How to Fix Moisture in a Crawl Space
Are you wondering how to fix moisture in a crawl space? If so, you’ll want to read this short article because it will tell you how to remove moisture in your home’s crawl space. We’ve been helping customers with crawl space moisture problems since 1994, so we have decades of experience handling this challenging problem. We know what works and what doesn’t.
In this article, we’ll talk about crawl space foundations, why crawl spaces get wet, how to fix moisture in a crawl space, and more.

What’s a Crawl Space Foundation?

A crawl space foundation – also called a pier and beam foundation – raises the house from 1.5 to 3 feet off the ground creating a space underneath the home that’s just big enough to crawl around in. Crawl space foundations have been popular for decades because they’re less expensive to build than basement foundations and provide easy access to the home’s plumbing system and electrical wiring. If the crawl space is encapsulated – we’ll talk more about this – you can use it to store things like holiday decorations, tools, etc.
pier and beam foundation infographic

Where Does Moisture In A Crawl Space Come From?

Crawl spaces get wet for various reasons including, but not limited to:
  • Leaky plumbing – The home’s plumbing is easily accessed via the crawl space. While this is convenient, it means that if there’s a plumbing leak, water will enter the crawl space.
  • Cracks in the foundation wall – These cracks don’t need to be visible. Even cracks you can’t see in a foundation wall can allow water to seep into a crawl space. This usually happens when there’s also poor drainage around the foundation. 
  • Hot, humid air – During the summer, the warm air coming in through crawl space vents will condense on cooler surfaces and create moisture.
  • Moisture in the dirt floor – A bare dirt floor in a crawl space will be full of moisture, especially if there’s poor drainage around the foundation or a high water table.
  • Poor drainage around the foundation – Poor drainage in the soil around any foundation can lead to all kinds of trouble, not just wet crawl spaces.
crawl space types of foundations in need of repairs

Why You Don’t Want Moisture In A Crawl Space

Crawl space moisture is bad for several reasons, including:
  • Mold growth – A damp crawl space is the perfect ‘Petri dish’ for mold growth. While you might be thinking who cares, I don’t live in my crawl space; think again. Some of the crawl space air flows into your home’s living area via the stack effect. (See illustration below) If the air in the crawl space is full of mold spores, the air in your home will be as well. This could cause health issues for anyone living in the house. Mold on crawl space beams and joists can also spread to the baseboards and floor above the crawl space. 
  • Wood rot – A wet crawl space also contributes to wood rot. If left unchecked, wood rot can severely damage the house’s structural integrity.
  • Dark, damp crawl spaces attract pests – Rodents – some with dangerous droppings – snakes, spiders, and wood-eating pests like termites love to take up residence in moist crawl spaces. 
  • Structural issues – Wet, soggy soil in a crawl space can cause the crawl space piers to sink into the ground, destabilizing the floor above the crawl space. If this happens, you might notice that the floor feels bouncy when you walk on it, or that furniture shakes when you walk by. 
Moisture in a crawl space may be common, but it’s not normal, and it always lowers a home’s value. Therefore, it should be fixed immediately, and that’s what we will talk about in the next section.
the stack effect Epp Foundation Repair

How To Fix Moisture In A Crawl Space

If the moisture in the crawl space is caused by poor drainage around the foundation, the solution is to get groundwater under control. Here are some ways to do that: 
  • Regrade your yard, if necessary, so it slopes away from your foundation. A yard that slopes toward the house will cause water to drain toward the foundation. This is a perfect way to end up with a wet crawl space.
  • Don’t forget to clean your gutters. Gutters clogged with leaves and other debris will cause water to spill over the side of the house, where it will soak into the soil around the foundation. 
  • Install downspout extensions, if necessary – Your downspouts should release water no less than four feet from the foundation. Extensions are inexpensive and easy to install.
  • Don’t plant vegetation next to the foundation – Flowers and shrubs might look nice next to the house, but you don’t want a reason to add water to the soil around the foundation.
  • Install a drain tile system – Nothing beats a drain tile system for controlling groundwater around the foundation. Find out how they work in How Does A Drain Tile System Work?
Excess water in the soil around the foundation isn’t the only way moisture gets into your crawl space. Here are some other things you can do to keep your crawl space dry:
If you’re wondering how to fix moisture in a crawl space and are in our service area in Nebraska, Iowa, Kansas, and Missouri, contact us today for an inspection and estimate.


Dave Epp

Dave is the President at Epp Foundation Repair with over 27 years of experience in the industry. Dave has worked on thousands of foundation, basement, concrete, and crawl space repair projects since 1993. Dave is involved in several civic and church organizations and enjoys coaching youth sports, mainly football, golfing, and elk hunting.



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