Water problems in and around your home can lead to serious issues—from foundation damage to mold growth and basement flooding. If you’re noticing signs of moisture, seepage, or pooling water, you might be wondering: Do I need interior drainage, exterior drainage, or both? Understanding the difference between the two systems is essential for choosing the right solution to protect your property.
What is Interior Drainage?
Interior drainage systems are installed inside your home, typically around the perimeter of your basement floor. They’re designed to collect and divert water that has already entered or is about to enter the basement through walls, floors, or foundation joints.
A typical interior drainage system includes:
- A perforated drain pipe installed along the basement footing
- A sump pit with a sump pump
- A vapor barrier or wall channel to direct water into the system
- Drainage to a safe discharge location (outside your home)
Best For:
- Homes with basement seepage
- Visible water stains or leaks on walls or floor
- Older homes without exterior waterproofing
- Budget-conscious solutions
What is Exterior Drainage?
Exterior drainage systems are installed outside the home, along the footing of your foundation, and are designed to prevent water from entering your home in the first place. These systems involve excavation, making them more labor-intensive but also highly effective at dealing with surface and groundwater.
A typical exterior drainage system includes:
- A weeping tile or perimeter drain pipe
- Gravel backfill and filter fabric
- A waterproof membrane applied to the exterior foundation walls
- Proper grading to direct water away from the home
Best For:
- New home construction or major renovations
- Properties with consistent groundwater pressure
- Homes where foundation wall protection is a priority
- Long-term, durable solutions
Key Differences at a Glance
| Feature | Interior Drainage | Exterior Drainage |
|---|---|---|
| Location | Inside basement floor | Around outside foundation |
| Purpose | Manage water that enters | Prevent water from entering |
| Cost | More affordable | Higher due to excavation |
| Installation Time | Quicker | More time-consuming |
| Disruption | Minimal | Significant (digging required) |
| Longevity | Moderate | Longer-term protection |
Which One Do You Need?
The right system depends on where the water is coming from and your home’s construction:
- If water is already entering your basement, or you want a cost-effective fix, interior drainage is your best bet.
- If you’re building a new home or doing major landscaping or renovations, exterior drainage offers better long-term protection.
- In some cases—especially with severe or complex water issues—a combination of both may be the ideal solution.
Signs You Might Need Drainage Help
- Wet or damp basement
- Water pooling around the foundation
- Mold or mildew smell
- Peeling paint or efflorescence on basement walls
- Cracks in the foundation
- Soggy lawn or yard flooding
Final Thoughts
Whether you choose interior or exterior drainage—or a combination of both—the goal is to keep your home dry, healthy, and structurally sound. If you’re unsure which approach is right for you, consult with a local drainage expert who can inspect your property and recommend the most effective solution tailored to your needs.
Need help with drainage in Vancouver? We offer expert interior and exterior drainage solutions for basements, crawl spaces, yards, and more. Contact us today for a free consultation.