How to Waterproof a Crawlspace

Crawl spaces are like that forgotten junk drawer in your kitchen—out of sight, out of mind, and usually full of unpleasant surprises. But unlike that drawer, your crawl space can actually mess with your home’s structure, air quality, and energy bills. If yours is damp, musty, or smells it’s probably time to waterproof it.

Luckily, we know a thing or two about waterproofing a crawlspace. So, let’s talk about what methods are actually used to waterproof a crawlspace, and why they matter if you like things like breathing clean air and not paying thousands in foundation repairs.

1. Vapor Barrier: The Moisture Forcefield

If your crawl space doesn’t have a vapor barrier, you might as well lay out a welcome mat for humidity. A vapor barrier is a thick plastic sheet (usually 6 to 20 mils thick—yes, thickness matters) that gets laid over the dirt floor to block moisture from seeping up from the ground.

Think of it like a raincoat for your crawl space—but way more useful. At Better Basements, we install heavy-duty vapor barriers that actually stay in place and don’t crumble after a season like that cheap roll you found at the hardware store.

2. Crawl Space Encapsulation: The Full Spa Treatment

Encapsulation is the VIP treatment of crawl-space waterproofing. It’s not just a plastic sheet tossed on the floor—it’s the full package: walls, floor, support piers, the works. Once encapsulated, your crawl space is sealed tighter than traffic on I-5 during a Ducks game.

We’re talking complete moisture control, reduced humidity, better air quality, and even lower energy bills. Plus, your HVAC system will stop wheezing like it just ran a marathon in a rainforest.

3. Interior Drainage System: Because Water Always Finds a Way

If water keeps creeping in, you’ll need an interior drainage system. This usually includes a network of perforated pipes installed along the perimeter of your crawl space that channels water to—wait for it—a sump pump.

Without drainage, that water’s just going to sit there making things worse. With drainage, it gets out before it causes mold, wood rot, or structural problems you really don’t want to discover during your next home inspection.

4. Sump Pump: The Unsung Hero

The sump pump is the unsung hero of crawl space waterproofing. It doesn’t get the spotlight, but it does the dirty work—literally. It takes all that groundwater collected by your drainage system and directs it out of your crawlspace for good.

Pro tip: get a sump pump with a battery backup. Power outages and storms tend to happen at the same time, and the last thing you want during a monsoon is a non-functioning pump sitting there like, “Good luck!”

5. Dehumidifier: Moisture’s Worst Enemy

You’ve sealed it up. You’ve drained the water. Now let’s dry the air. A high-capacity dehumidifier can help keep the relative humidity under control and prevents mold from sticking in your crawlspace.

Crawlspace waterproofing isn’t optional if you value your home’s health (and your own). It’s not just about avoiding puddles—it’s about protecting your foundation, your indoor air quality, and your investment.

At Better Basements, we don’t cut corners—we seal them. So if you’re tired of the mystery smells and moisture-induced anxiety, give us a shout. We’ll turn your crawl space from horror movie set to clean, dry, and drama-free.

Get a free crawlspace inspection today because pretending the crawl space doesn’t exist won’t stop the mold.

You can catch up with me on social media where I share thoughts, projects, and updates. Feel free to follow along!

Dylan Milroy – Co-Owner

REVIEWS

What People Say

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Denise A profile picture
Denise A
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From start to finish, Better Basements and Waterproofing was great to work with. I found everyone to be customer focused. They were amazing in answering all my many questions.
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Russell Mantifel profile picture
Russell Mantifel
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Timely. Communicative. Flexible. Quality.
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Brian Eubanks profile picture
Brian Eubanks
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Great service and friendly staff. People were on time and really helped when I had questions. Job was quick and was cleaned when it was finished. Thank you.
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Seth Miller profile picture
Seth Miller
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These folks are awesome to work with. Hyper punctual, knowledgeable, and flexible. Not pushy at all and seem to simply want your water problems to go away. I don’t feel their techs would offer or recommend doing anything they wouldn’t do to their own homes.
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Kathleen Jones profile picture
Kathleen Jones
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Courteous and friendly and did everything they needed to do in our crawlspace. Also kept dirt and dust down to a minimum and tried to keep the costs down. Would highly recommend!
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Tim Barbknecht
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Knowledgeable, friendly, no “up sales” just honest assessments. I will hire these guys when I’m ready.
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Nicholas Mitchell
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Highly professional company. Highly recommended
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Tyler Buschman profile picture
Tyler Buschman
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These guys are pros. They replaced old vapor barrier and insulation in the crawl space and installed a sump pump and fan for our house. Everything was done in a timely matter and looked great. I can now sleep with peace of mind. Would definitely recommend to anyone needing work done beneath their home.
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Ryan James profile picture
Ryan James
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Team was super responsive and great ! We had crawl space encapsulation and also some foam spray done, with sump pump and dehumidifier. I thought they did an awesome job and really helpful throughout the process. Highly recommend !