Interior Waterproofing

What Interior Waterproofing Involves

Interior waterproofing installs a perimeter drain — sometimes called interior weeping tile — along the inside edge of the footing, just beneath the basement floor. A section of concrete floor is cut and removed along the wall, the drain is laid in a bed of gravel at the footing level, and it’s connected to a sump pump and pit that discharges the water outside, away from the foundation. The floor is then patched back over the drain. We’re upfront about what this does and doesn’t do: it manages water that has already entered the space between the wall and the drain, moving it away before it becomes standing water on your floor. It doesn’t seal the outside of the wall the way exterior waterproofing does.

That makes interior waterproofing the right call in specific situations rather than a universal fix. It’s a strong option when the exterior isn’t reasonably accessible — finished landscaping, a deck or patio built over the area, a shared wall with a neighbouring property, a narrow lot with no excavation room, or simply a lower budget than a full exterior dig requires. Our interior vs. exterior waterproofing guide lays out the honest trade-offs between the two so you can see which one actually fits your property.

What’s Included

• Floor assessment and cutting along the affected wall to expose the footing area where the drain will run.
• Interior perimeter drain installation set in gravel at the footing, collecting water before it reaches the living space.
• Sump pump and pit connection so collected water is pumped out and discharged well away from the foundation.
• Floor patching and cleanup once the drain system is tested and confirmed to be working properly.

What to Expect

1. Inspection & assessment. We confirm water is entering along the wall/floor joint and check whether interior drainage is the right fit.
2. Written estimate. A clear scope and price before any cutting starts.
3. Floor cutting & excavation. A channel is cut and dug down to the footing along the affected wall.
4. Drain, gravel & sump connection. The perimeter drain is laid and tied into the sump pump system.
5. Floor patch & test. Concrete is patched back and the system is tested to confirm it’s draining and pumping correctly.

When to Call Us

Interior waterproofing is worth discussing whenever water is entering along the base of a basement wall and exterior excavation isn’t realistic or appealing. Call sooner if you notice:

Frequently Asked Questions