why you need a crawl space drainage system
July 11, 2022

A crawl space drainage system protects your home’s structural integrity and your health. This article will cover what a crawl space is, how crawl spaces get wet, how crawl space drainage systems work, crawl space encapsulation, and other ways to keep your crawl space dry.

What Is a Crawl Space?

A crawl space foundation lifts a house approximately 1.5-3 feet off the ground and creates a space under the house that’s just big enough to crawl around in.

Crawl space foundations have been popular for decades, and when they’re waterproofed and encapsulated (more on this below), they can be used to store things like holiday decorations, tools, canned food, etc.

Why A Crawl Space Drainage System is required in a home

Why Do Crawl Spaces Get Wet?

Crawl spaces get wet for various reasons, including the following:

  • Crawl spaces have uncovered dirt floors. If the soil gets wet, the crawl space will be wet.
  • Crawl spaces are vented. This allows warm, humid air to enter and condense on cooler surfaces, encouraging mold growth on wooden structures in the crawl space.
  • Crawl spaces sometimes have leaking drainage pipes in them.

For more information see, Crawl Space Waterproofing: Why You Might Need It.

Why You Don’t Want a Wet Crawl Space?

A wet crawl space encourages mold growth. You don’t want mold growth in your crawl space because some air from the crawl space ends up in your home’s living area. Breathing mold spores can cause allergies and other respiratory issues – some potentially serious – for anyone living in the home. Mold will also eat away at the beams and joists in the crawl space, affecting your home’s structural integrity.

A wet crawl space also attracts pests like wood-eating termites, snakes, and rodents that leave behind toxic droppings.

If the above weren’t bad enough, if the soil under your home is prone to erosion, a wet crawl space will slowly destabilize the piers holding up the home by washing away the soil.

Bottom line: If you want a healthy home, the crawl space should be kept clean and dry. Fortunately, there’s a way to do that.

benefits of waterproofing a crawl space

What Is a Crawl Space Drainage System?

A crawl space drainage system ensures that the soil around the home’s foundation and crawl space doesn’t get saturated with water that can’t drain off. When the soil around the crawl space is dry, your chance of having a wet crawl space is significantly reduced. So, getting groundwater under control via good drainage is the key to effective waterproofing. In fact, a crawl space drainage system along with a sump pit and sump pump can even keep your crawl space dry during storms.

Crawl Space Drainage System Installation Process

  • Any debris is removed from the crawl space.
  • A shallow trench is dug around the inside perimeter of the crawl space, along with a sump pit.
  • The trench is lined with gravel.
  • A perforated drainage pipe is placed in the trench and covered with more gravel.
  • The excavated dirt is replaced.

Excess water in the soil will go into the drainage pipe and be directed to the sump pit. When the sump pit fills with water, the pump kicks in and expels the water away from the foundation.

Crawl Space Drainage System

A Crawl Space Drainage System Plus Crawl Space Encapsulation

After installing a crawl space drainage system, homeowners often encapsulate their crawl space as well. Crawl space encapsulation involves covering the floor and walls of the crawl space with a thick vapor barrier. This seals off the crawl space from moisture in the dirt floor and from any moisture that finds its way through the foundation wall.

If you want to kick it up a notch, you can add a dehumidifier as well for a crawl space that’s both clean and extra dry.

Wet Crawl Space Solutions

If you can’t afford a crawl space drainage system right now, that doesn’t mean you’re totally out of luck. There are other things you can do that will help keep groundwater around your home’s foundation under control. These include:

  • Regrade your yard, if necessary – The yard around your home should slope away from the foundation. You don’t want water draining toward the foundation.
  • Don’t forget to clean your gutters – Clogged gutters will cause runoff to go where you don’t want it. That is, over the side of your home, where it will soak into the soil around the foundation.
  • If your downspouts are too short, install extensions – Downspouts should channel water at least 10 feet away from the foundation before releasing it. Downspout extensions are inexpensive and easy to install.
  • Consider underground downspouts with pop-up emitters – Another option is to channel runoff from the gutters into underground downspouts with pop-up emitters situated 10 feet or so from your foundation. When the pop-up emitter basin fills with water, it pops up and releases it away from the foundation.
  • Don’t plant vegetation around the foundation – You want to avoid any reason to dump water in the soil around the foundation.

If you think your home might need a crawl space drainage system and are in our Kansas City, MO service area, contact us today for an estimate.

Top waterproofing contractors Kansas City
home-advisor-elite-service-award-1
Lifetime Transferrable Warranty
Top Companies In Kansas City Foundation Repair

Get Your Free Guide

15 Preventative Maintenance Tips For Your Foundation

This Preventative Maintenance Guide shows you the top 15 causes of foundation problems. Download now to protect your home, add value, and prevent damage to your home’s foundation.

This field is for validation purposes and should be left unchanged.

Satisfied Customer Reviews

Mario came out to seal a crack on my stairs and fill a settlement crack in the basement. He was very professional and friendly. He did an amazing job and I was very impressed.
Didn't waste any time. I have a big problem and he told me from the beginning that they couldn't handle it. He helped give me some advice and direction... and did not try to sell me on something he knew they couldn't deliver. I appreciated his upfront honesty and advice.
They are a fantastic company and really went above and beyond to make sure we got the information we needed.
Mario was great! He very informative and helpful! I would highly recommend him!
Mario came out to check the sump pump. After cleaning the pit out and checking both the main and backup pump he wiped everything done and left the area cleaner than when he got there. Very friendly and knowledgeable guy!
Don Derry with KC Waterproofing has been our "go-to" foundation repair specialist since 2005! We have had him to our homes multiple times. The project always wraps up with us having peace of mind. This past time with 14 piers installed, was no exception. His crew was polite and respectful. They cleaned up our property perfectly at the conclusion of the project. I highly recommend this foundation repair company.
Tech was on time completed the repair as necessary, and the experience was great.
We recently had KC Waterproofing out at our home in North Kansas City, and I cannot say enough great things about Ryan Marshall and his team (Austin & Jacob). They worked at our property over the week of July 17/2025 - and absolutely blew us away with their professionalism, work ethic, and transparency.

Ryan took the time to thoroughly explain the problems we were facing, what caused them, and exactly how they were going to fix them. His honesty and willingness to go the extra mile truly set him apart.

Ryan and his assistant worked hard, were respectful of our home, and made sure everything was done right the first time. It's rare these days to find that level of care and craftsmanship. Because of professionals like Ryan, we’ll continue to turn to KC Waterproofing for future needs.

Highly recommend this company—especially if you get the chance to work with Ryan and his crew! When it comes to foundation issues we will always recommend KC Waterproofing. They have been in the business, are trusted, and will do the job correctly.
I recommend KC Waterproofing. They kept me informed as the job went along. They started and ended as they had said. Cleaned up each day before they left. Price was fair and they were able to stabilize walls without excavation which was good so I didn’t have to deal with landscaping. Fran and Julian were professional and easy to work with.
Inspection completed throughly and efficiently. Technician was professional and pleasant.