French Drains: Basement Solutions

Feeling damp and drippy? If your basement walls are clammy, a French drain system — also called a footing drain — can banish that boggy feeling.

french drain basement solutions
Image: StayDry Basement Waterproofing of Michigan

If water is a chronic problem in your basement and other solutions, such as diverting downspouts, building up foundation soil, and installing a curtain drain don’t correct the problem, you’ve got two main options: installing either an s or an exterior French footing drain.

Both systems install next to your foundation footing. Neither is a DIY project, and each has advantages. Here’s what you need to know.

Installing an Interior French Footing Drain

An interior French drain doesn’t prevent water from entering your basement. Rather, it catches water that seeps inside and channels it by gravity to a sump pump that sends the water back outside or into a drain line.

To install an interior French drain, a waterproofing contractor cuts a channel into your basement slab around its perimeter. They excavate the ground below the channel, install perforated drain pipe and a sump pump well, and fill the trench with drainage gravel. Then they patch the slab with fresh concrete.

Advantages:

  • Doesn’t disturb exterior landscaping
  • Basement is readily accessible in all weather, so work proceeds on schedule
  • Costs less than an exterior footing drain

Disadvantages:

  • Can’t stop wall seepage, so applying wall finishes remains problematic
  • Sump pump won’t function during electrical outages without a battery or generator backup
  • Cutting concrete is messy and noisy

Cost: $3,000 to $4,000

Related: Fix Wet Basement Problems

Installing an Exterior French Footing Drain

An exterior footing drain is one of the surest solutions for a wet basement. It’s also one of the most expensive. This system requires a thorough excavation to expose your foundation walls and footings. So, it gives allows you to apply a waterproof coating or membrane to the exterior surfaces of your walls for added protection.

To install an exterior footing drain, a waterproofing contractor digs around the outside of your foundation with a backhoe. They apply waterproofing to your basement walls, then install a French drain system next to the foundation footing. Then they fill the excavation with gravel to promote drainage.

If your lot is sloped, the drainage will flow by gravity to an exit point or a storm drain system. Otherwise, you’ll need an exterior sump pump to move the water away from your house.

Advantages:

  • Waterproofs basement walls from the outside
  • Large excavation ensures good drainage next to the foundation
  • Removes water before it can enter basement

Disadvantages:

  • Working a backhoe around your property may destroy landscaping features
  • All plantings at the dig site will be removed
  • Expensive

Cost: $9,000 to $15,000 (including waterproofing walls)


John Riha

John Riha

John Riha has written seven books on home improvement and hundreds of articles on home-related topics. He’s been a residential builder, the editorial director of the Black & Decker Home Improvement Library, and the executive editor of Better Homes and Gardens magazine.