7 Green Basement Waterproofing Options That’ll Help Stop Leaks in Its Tracks

Allie Ogletree
Written by Allie Ogletree
Updated December 15, 2021
A spacious kitchen and a dining area in the basement of a house
Photo: PhotoSerg / Adobe Stock

Keeping your basement dry has never been so green

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It’s every basement owner’s worst nightmare—water wreaking havoc on an already dark and sparsely windowed room. Fortunately, basement waterproofing can help prevent flooding and water damage. And the best part is you can make sustainable basement waterproofing choices that have little to no negative impact on the environment.

Here are seven eco-friendly measures for preventing basement leaks and floods. 

1. Start with Your Gutters

One of the best solutions for a waterproof basement is to ensure your home never needs it. Waterproofing begins with your gutters—not your basement itself. Ensure that your gutters are:

  • The right size: Large enough to handle the water pouring down from your roof 

  • The right width: Wide enough to sufficiently extend away from the house so that water drains away from the yard rather than toward your house 

  • Properly configured: Downspouts should be angled away from the home (a local basement waterproofing pro can advise whether you need splash blocks to further divert water away from your home 

  • Clean: Clear of mold, mildew, ice, and other blockages (consider choosing a gutter guard to keep out debris)

Once your gutters are up to par, install a rain barrel to the ends of your downspouts to catch rainwater. This is a great option for those living in hot or dryer climates, as you can use the water to keep your yard looking green on scorching hot days or during times of drought without having to use (read: waste) tap water. 

2. Tweak Any Slopes

Make sure soil near your home slopes away from the foundation rather than toward it—otherwise, even the best gutters will direct rainfall toward your basement. According to the EPA’s Moisture Control Guidance, you should aim for a 5% slope away from the wall of your home. For example, if you measure the slope of your soil at 10 feet away from your home, it should be approximately six inches lower than the start of the grading. 

Consider talking with a nearby professional yard grader to help you evaluate the grading of your land and determine if you need to make any changes to your current setup.   

3. Add a Berm

The exterior of a house with the garden having a berm
Photo: qingwa / Adobe Stock

Some landscape features can prevent water from ever getting near your house. One of these landscape strategies for keeping out water is berms, aka piled-up dirt mounds. Don’t let its funky description fool you; berms can protect your home as a miniature dam would, and when combined with swales (or ditches), they can also divert water away as it approaches. 

Berms can be especially effective if slopes near your house send water toward your basement or other areas you’re trying to protect. The most effective berms are five to six times longer than the height, with a gradual slope away from your home. Avoid constructing berms that are more than two feet tall, and don’t be afraid to contact a local landscaping design professional to help you design one that also functions as curb appeal (yes, it’s possible).

4. Create a Swale

As mentioned above, adding a swale to your landscape can further help prevent flooding. Swales are drains or subsurface trenches filled with grass as part of a green infrastructure practice or filled with piping and gravel to catch underground water as it travels and seeps into the ground. Install them near drainage pipes or other areas where water collects to catch runoff water. 

Like the other methods we’ve described here, swales have a minimal environmental impact. Swales research shows that they can retain anywhere from 14% to 98% of nutrients and 93% of metals, which helps preserve essential soil nutrients and remove metal runoffs from public drainage systems. 

5. Ditch the Impermeable Hardscapes

All that concrete and asphalt might look sleek and modern, but it can also increase your chances of experiencing a flood because runoff water has no place to go other than down the pavement. Since water can’t reach the soil underneath the hardscape materials, one solution is to switch to softscape materials.

These include:

  • Permeable pavers: Allow for water to seep into the ground below for filtration and flood prevention better than asphalt or concrete

  • More gardens: Plant native herbs, flowers, and other greenery specifically designed for your home’s climate. They’ll drink up more water and encourage plant and wildlife growth.

  • Gravel, decomposed granite, and sand: Combine gravel with sand or crushed granite, which works well at preventing flooding. It’s also less slippery underfoot than muddy walkways.

6. Coat Your Basement Walls

The basement of a house serving as a large living room
Photo: Iriana Shiyan / Adobe Stock

In some cases, even the most effective exterior solutions can’t completely protect your basement from water. Double down on basement waterproofing in the interior of your home by sealing cracks in the foundation. Interior and exterior wall coatings can block water from sneaking inside, but not all coating materials meet environmentally-friendly standards. 

Below are two standards for finding green water-proofing sealants:

VOC Standards for Sealants

Look for eco-friendly sealants that contain lower volatile organic compounds (VOCs). VOCs are compounds that release chemicals into the air when they dry and evaporate. These chemicals can linger indoors, irritating the nose, eyes, and lungs and increasing allergies and asthma symptoms for those who suffer from such conditions. 

The national standards for VOC emissions are up to 250 grams per liter (g/L), but for eco-friendly low-VOC paints, you’ll want one that has a rating of no more than 50 g/L

Eco-friendly Sealant Materials

Additionally, certain materials are much greener than others. Take a sodium bentonite waterproofing system, for instance. This basement waterproofing solution uses a form of moisture-absorbing clay to soak up water and draw it away from the basement. However, it can be very difficult to install in existing construction and is therefore often used as a spot fix to fill cracks. You also have to be careful if it’s used outside—if it’s washed away, it can get into drains and block them up.

A crystalline waterproofing technique is also relatively environmentally-friendly. This method involves applying a crystalline treatment that soaks directly into the concrete and makes it impermeable to water.

Ask your basement contractor to recommend other zero-VOC or low-VOC sealants that have the same effect as standard sealants and are also less harsh on the environment. 

7. Apply a Water-Proofing Floor Stain

Just like your basement walls, your hard floors are prone to damage if water manages to sneak in. Even small traces of water damage can increase the humidity in your basement and cause wood and laminate flooring to rot and warp. Stain your floors with an ultra-low VOC stain (following the same guidelines as you did for your sealants) to secure your entire basement.

Applying a water-proof stain is a great “last-ditch effort” or “worst-case scenario” solution for protecting your floors in the event of water leaks. This water-proofing tip only works for hardwood and laminate floors. Carpet, unfortunately, won’t stand a chance against water damage.

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