French Drain System for Basement Waterproofing | Types | Pros and Cons

Apr 23, 2019

Is your basement the victim of water damage issues like excessive moisture, dampness, foul odor or molds? If yes, a French drain system can easily banish all these issues. Many people try diverting downspouts, build up foundation soil or even install curtain drain, but sometimes none of them correct the water damage problem in the basement. There are generally two popular options under basement waterproofing service – one is Interior French Drain System around the basement slab perimeter and another is Exterior French Drain System outside basement walls.


Interior French Drain System

Rather than preventing water from entering your basement, the interior French drain catches the water that seeps inside and directs it by gravity towards a sump pump which sends water back outside or into the drain line. In order to install this French drain system, basement waterproofing service provider cuts a channel into your basement slab along its perimeter. The ground is excavated below the channel and perforated drain pipe and sump pump are installed. After that, excavation is filled with drainage gravel and then the slab is patched with concrete.

High Points:

  • Doesn’t mess with the exterior landscape.
  • Basement is accessible in all weathers so work is carried according to schedule.
  • Cost is less.

Low Points:

  • Can’t stop wall seepage so applying wall finishes remains troublesome.
  • During power outage, sump pump won’t work without battery or generator backup.
  • Noisy process


Exterior French Drain System

The exterior French drain system is considered to be one of the best basement waterproofing solutions. However, it is also expensive. Since this system requires a thorough excavation to expose the foundation walls and footings, it provides the opportunity of applying waterproof coating or membrane to the exterior surfaces of the basement walls for extra protection.

In order to install this system, the workers dig around the foundation and apply waterproof coating to the walls of the basement. Then, a French drain system is installed next to the foundation footing and excavated area is filled with gravel to promote drainage.

In case your area is sloped, the drainage will flow by gravity to the exit point or storm drain system, otherwise, you will need a sump pump to channel the water away from the basement.

High Points:

  • Outside waterproofing of basement walls
  • Good drainage next to the foundation due to large excavation
  • Move water away from the basement and prevents its seepage through walls

Low Points:

  • May destroy some of the landscaping features (if they lie in the designated area of excavation)
  • All plants are removed from the digging site.
  • Cost is high.


If you are also facing water damage problem in your basement, hire basement waterproofing service from one of the reputed contractors, choose the waterproofing option accordingly and make your basement free from water damage issues as early as possible.