Exterior Foundation Waterproofing

Exterior foundation waterproofing is the most thorough way to keep water out of an Ottawa basement. We excavate down to the footing, clean and repair the foundation wall, apply a waterproof membrane and dimple board and lay fresh weeping tile to a drainage point. It stops water before it ever reaches the wall. That makes it the right choice for chronic leaks and older homes.

Because it tackles the problem from outside, an exterior membrane is the longest-lasting solution we offer. It is ideal for character homes with stone or rubble foundations and for any house where water has been getting in for years rather than during one bad storm. For how it compares with sealing a wall from the inside, see our guide to foundation sealing in Ottawa.

Exterior work is a bigger job than an interior fix, so we only recommend it when the water path genuinely calls for it. During your free inspection we will tell you honestly whether a simpler interior system or crack injection would solve the problem for less. See how the two stack up in our interior vs exterior waterproofing guide.

What this fixes

• Chronic, long-standing foundation leaks
• Porous stone, rubble and early-concrete walls
• Failed original waterproofing on older homes
• Lateral water entry below grade

Wondering about price? Try our cost calculator or read ourHow Much Does Basement Waterproofing Cost in Ottawa? (2026 Guide).