The right foundation drainage system can prevent expensive repairs and major leaks
The type of drainage system best for you depends on your foundation style.
The French drain is widely considered the most effective option.
Proactive solutions to basement moisture are always preferred.
There are four types of foundation drainage systems you can install to minimize the risk of damage and avoid expensive foundation repairs, including sump pumps and floor drains as reactive solutions to avoid water buildup, as well as French drains and footing drains as proactive solutions to avoid water intrusion altogether. In this guide, we’ll explain how to choose the best option for your home.
A sump pump is a water pump that a contractor installs in a pit—often called a sump pit—that sits below the foundation floor in a crawl space or basement. Since it’s the lowest point in the sub-home area, it fills with water first, at which point the pump turns on and pumps the water outside or into the sewer main.
Sump pumps will not prevent water from getting into your crawl space or basement and instead serve as a purely reactive solution to water that does get in. You can still have moisture and water damage issues if you have a sump pump. Sump pumps also require electricity, so they may not offer any help in the case of a severe storm that knocks the power out and floods your under-home area.
| Pros | Cons |
|---|---|
| Flood protection | Reactive solution |
| High volume | Take up floor space |
| Affordable | Loud during use |
| Treat plumbing leaks | Require electricity |
Best For: Removing large amounts of water that has already entered into a crawl space or basement
A French drain consists of a trench covered by gravel spanning the perimeter of your home, as well as a perforated pipe that runs underneath the gravel. Rather than soaking into the soil and becoming an issue for your foundation, runoff drips through the gravel and into the perforated drain pipe.
The pipe redirects water away from your foundation to a safe disposal area. Depending on your property, that might be a space in your yard or in the street, but some areas don’t allow for French drains if there isn’t a safe disposal area that won’t affect your neighbors or municipal drainage systems.
French drains are widely considered the best solution for preventing foundation leaks, but they have their drawbacks as well. First, French drains cost around $9,250, making them one of the more expensive options. Second, they sit underground, but you’ll still have a visible strip of gravel traveling around your home, and putting weight over that area can crush the pipe.
Finally, they can get overwhelmed under high volumes of water, so they may not help much if your area floods often. Consider a sump pump over a French drain or in addition to one if you see flooding in your home.
| Pros | Cons |
|---|---|
| Preventative measure | Can overflow |
| Low maintenance | Expensive |
| Exterior solution | Visible from curb |
| Reduce soil movement | Not legal everywhere |
Best For: Keeping water and moisture away from your foundation in areas that aren’t prone to flooding.
A floor drain—also called a weeping tile—is a trench dug out of your foundation slab, usually around the inside perimeter of your crawl space or basement. They sometimes appear on patios or pool decks to keep outside water away from your foundation, though. The trench slopes downward toward a specific place for water disposal, which is often a sump pump. A floor drain can be effective for minimizing pooling water that a sump pump alone might not dispose of right away. Much like sump pumps, floor drains are reactive and won’t keep water out of your crawl space or basement.
Floor drains take up more floor space than a sump pump, so they’re not practical if you have a finished basement. They can also get overwhelmed more easily than a sump pump, so they’re best for under-home areas that see minimal water intrusion and may not help quickly enough in the case of a flood or standing water.
Floor drains are also expensive to install retroactively, as they require excavation of your concrete slab and the installation of drainage pipes under the surface of the concrete.
| Pros | Cons |
|---|---|
| Reduce pooling water | Reactive solution |
| Treat plumbing leaks | Expensive |
| Interior or exterior | Install is invasive |
Best For: Removing small amounts of water that makes its way under your home
A footing drain is similar to a French drain, but instead of sitting just a foot or two beneath the surface, they sit however deep your footings go, which can be 10 feet or more. Footing drains help reduce the risk of soil saturation under and around your footings which can lead to foundation instability and structural damage. They require the most excavation and can be quite expensive unless you’re installing them at the same time your contractor is pouring your foundation.
Footing drains won’t do as much as a French drain would to keep runoff away from your foundation because they sit too deep under the ground. As such, they often won’t prevent water from wicking through your foundation walls or cracks in your foundation. Instead, they prevent heavy water volumes from reaching beneath your footings and causing structural issues.
| Pros | Cons |
|---|---|
| No structural damage | Not ideal for runoff |
| Minimal crush risk | Walls can still leak |
| Proactive solution | Expensive |
Best For: Avoiding structural damage caused by expansive soil when building out new construction
Water causes the biggest threat to foundation stability and overall foundation health. It can cause problems whether it soaks into the soil around your home and stays outside or seeps through foundation cracks or pores in the concrete and makes its way inside.
When runoff soaks into the soil around your foundation, it can cause it to expand and put added pressure on the concrete, potentially causing damage. When the soil dries, it shrinks and pulls away from the concrete, leaving it improperly supported. These problems can both lead to structural damages. The water can also soak through your foundation and accumulate under your home, promoting moisture issues, mold growth, pest infestation, and damage to building materials.
"Maintaining the right slope and proper landscaping is crucial. The ground around your home should slope away from the foundation to prevent water from pooling. Don’t plant trees too close to your house because their roots can damage the foundation. Avoid heavy watering near the foundation and use appropriate mulch and ground cover to manage moisture levels."
— Tim O'Shea, The Build Pros
Foundation damage is so critical because it helps avoid all of these issues. Preventative solutions like French drains and footing drains help keep water outside, and reactive solutions like floor drains and sump pumps help limit damages caused by pooling and standing water.
If you don’t have proper drainage in place or are experiencing issues with your old foundation drainage system, call a foundation drain installation company near you to assess the problem and implement a permanent solution.
Most people consider a French drain to be one of the most effective solutions for foundation leaks, but it’s not always a standalone solution. French drains will help keep water away from your foundation to reduce the risk of leaking and structural damage from soil expansion, but depending on your foundation type and location, you might need other systems or techniques—like soil gradation and gutter and leader installation—to resolve the underlying problem.
French drains and footing drains are virtually identical, except that French drains sit a foot or two beneath the ground, and footing drains sit as deep as your foundation footings go, sometimes up to 10 feet. Both drainage systems collect water before it reaches the soil around your foundation and divert it to a safe place on your property for disposal.
You should always cover a French drain with gravel rather than dirt. Gravel will let water seep into the drain more easily, which means the drainpipe will collect more water and divert it away from your foundation. Dirt over a French drain will also clog the pores in the drainpipe over time, rendering your drainage system useless until you excavate the line and clear it, a time-consuming and potentially expensive process.
