Foundation Drainage Systems: What’s the Difference Between a French Drain and Channel Drain?

Do you have poor drainage near your foundation that collects water after a storm? If so, you’re in danger of rainwater seeping into your basement.

When this happens, you not only have to worry about water damage to anything stored in your basement, but you have to worry about mold and mildew growth. So, proper drainage is a major concern if you want a dry basement or a backyard patio.

What can you do to make sure rainwater drains away from your foundation and yard?

Two of the most effective drainage options for your home are a French drain and a channel drain. Read more about the differences between these two drains. Also, find out which one is right for your drainage situation.

Facts About Drainage

Poor drainage causes several problems, such as standing water, foul odor, bug infestations, diseased plants, mud, and ruined lawns. When you plan and install effective drainage, these problems will disappear. Proper drainage can prevent water nightmares during rainstorms.

Did you know there are two different types of drainage? One is surface drainage and the other is subsurface drainage. When you’re deciding whether you should install a French drain or a channel drain, you should first know the type of drainage you need.

Surface

During heavy rain, surface drainage can divert large amounts of water away from your foundation. This prevents flooding basements and topsoil erosion.

Subsurface

On the other hand, subsurface drainage removes groundwater. This is water that accumulates under your driveway, basement, and landscaping. It often happens from high water tables or very wet weather.

The groundwater follows gravity, collecting under pavement and saturating the soil.

Good drainage requires you to find the low spots in your yard and around your foundation. You can tell where these spots are located because you’ll see puddles and standing water after it rains. For sufficient drainage, you need at least a one to two percent slope.

You could also do a percolation test to measure the drainage in your yard. This will tell you how long it takes water to drain from your lawn.

Once you calculate the slope you need, grade the area so your drain will slope away from your house and flow toward the discharge area.

What Is a French Drain?

A French drain uses a trench that’s deep enough and wide enough to surround a perforated PVC or corrugated plastic pipe that you cover with gravel. For homeowners, 4 to 6-inch pipe should do the trick.

The drain prevents water from seeping into your basement by diverting it into the trench. Then the water flows into the pipe and travels to a discharge outlet.

Some examples of discharge outlets are a swale, storm drain, out to the street or to a sump pump. For this to work, the French drain system has to follow the natural water flow sloping from high ground to discharge at a low point.

French Drain Installation

These tips are just the basics of installing a French drain. It’s always a good idea to have a professional drainage installer put in your French drain to ensure no water still finds its way into your basement.

When installing this type of drain, you line the bottom of your trench with about 2 inches of gravel. Place the pipe into the drain with the perforated side facing down. Then cover the pipe with 4 inches of gravel over the top. You should also have at least one inch of gravel around the sides of the pipe.

Some French drains are open with the gravel coming all the way to the top of the trench. If you’d rather have the drain blend in with your landscaping, you can cover the gravel with up to 4 inches of topsoil. Placing silt fence or geotextile over the gravel will prevent the soil from clogging the gravel.

What Is a Channel Drain?

A channel drain is similar to a French drain but has a few differences. You might also hear it called a trench drain. Like the French drain, the water flows through it in an underground channel. The drainage system diverts water runoff across large areas.

Rather than using perforated pipe like the French drain, channel drains are constructed with fiberglass, plastic or steel drain tubes placed on top of poured concrete.

Commercial buildings often have channel drains around their foundations to keep walkways dry. These drains also work for residential homes when installed around the foundation.

Channel Drain Installation

Channel drains give you long-term drainage if you install them the right way. Just like the French drains, you need to dig a trench that slopes away from your foundation or yard. After digging your trench, you pour concrete as your base.

Channel drains come in assorted materials, such as polypropylene and plastic. You can also connect corner and T connectors to your channel drain for customizing them to fit around your foundation.

These materials resist chemicals that drain into the trench from fertilizers, insecticides, and herbicides used on your lawn.

When you put the cover grates on your channel drain, you can find decorative and colored ones that blend in with your landscaping. You can also remove them for cleaning. This is an important maintenance step to keep the water running freely into the trench.

Where to Use a Channel Drain

Most likely, you’ve seen channel drains in the following locations:

• Patios
• Driveways
• Garden areas
• Golf courses
• Parking lots
• Pool areas

These drains divert water away from large areas. They also reduce erosion in your yard, if you lived in a sloped area.

Choose a French Drain or Channel Drain for Better Drainage

Whether you choose a French drain or a channel drain, both stop basement leaks and soggy landscape soil. You need adequate drainage if you want to transform your backyard into living space without worrying about mud and a saturated lawn.

These trench drains intercept water moving toward your home. They’re the drainage solutions you need during heavy rain or in high water table areas.

If you live in the Greater Houston, Katy or Memorial area, schedule a consultation with our professionals to help you with drainage solutions, so you can enjoy more outdoor livable space.