If you have excessive moisture entering your basement through the walls or floor, it’s likely a groundwater issue.
The first step in remedying this situation should be examining your gutters, downspouts and soil grading. They’re an easy, affordable fix. But if those elements are in good shape, you should look into a drain tile system. This lesser-known feature is a powerful defensive barrier that directs water away from your home and keeps your basement dry.
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What Is Drain Tile?
When most people hear the term “drain tile,” they picture the round or square grate found in many basement slabs. It’s a reasonable assumption, but those are actually called floor drains.
A “drain tile” refers to a system of perforated pipes laid along the foundation, inside or outside. Also known as French drains or perimeter drains, these system channels water away from the home. French drains are generally outside.
How Does Drain Tile Work?
The concept is simple: The system captures groundwater before it enters the basement. It passes through a series of filters, then enters the pipe and travels along its length to a sump pit or other discharge point.
Today the pipes are typically made of PVC, but they were originally clay. These segments were called “tiles,” and the name still survives even for modern techniques.
Drain Tile System Elements
These depend on whether it’s an interior or exterior drain and the specific installation, but the core concepts are universal.
Trench
The route the drain system takes along the perimeter of the home, either outside or inside the foundation. The trench should gently slope toward the runoff destination.
Pipe
The pipe sits in the trench. It needs to be robust enough to withstand weight from above, while maintaining enough flex to handle shifting pressure from soil and water. The pipe is perforated and surrounded by layers of gravel or fabric filtering.
Covering
A layer of soil (exterior systems) or concrete (interior systems) covers the pipe and trench.
Pump
Of course, it’s not enough to simply collect groundwater. The system must direct it somewhere.
Exterior drains often “drain to daylight,” meaning they channel water to an appropriate location away from the home, like a street discharge or dry well. Interior systems almost always drain to a sump pit, where a pump draws excess water out of the home.
4 Signs You Need Drain Tile
If you can answer “Yes” to any of these four questions, you should consider a drain tile system repair or installation:
- Does your basement have water issues even though your gutters are working?
- Do you have wet basement walls?
- Is water seeping up from your basement floor?
- Do you have plans for a finished basement, or want to store valuable items in your basement?
How Much Does a Drain Tile System Cost?
It depends. Drain tile installation costs are mostly labor-based, with most going toward digging the trench and/or breaking up and removing concrete. Prices will vary greatly depending on the local market.
In general, prices for exterior drain tile retrofits run from $20 to $60 per linear foot, while interiors range from $60 to $100 per linear foot. That includes the price of pipe, gravel and any pit or pump required.
Note that exterior systems will typically measure the full house’s footprint plus the length to the street discharge location. An interior system will only be based on the size of the basement.
Can I DIY Drain Tile?
Yes. The technical skills are well within reach for most DIYers, though it’s a dirty job. If you go the DIY route, consult online guides and any appropriate codes and regulations. Chapter 33 of the International Residential Code (IRC) covers storm drain systems.
Plan your project carefully. Exterior systems often run into problems with landscaping; bushes and patios may need to be removed or altered.
Interior drain tile systems are typically more straightforward. The hardest part is often hauling the concrete and mud out of your home without making a mess. Homes on crawlspaces can pose accessibility issues. Imagine digging a drain trench while laying on your side!
Whether you DIY drain tile or hire a pro, installing a new system provides a dry basement and a sense of security.
Originally Published: December 08, 2022
