Exterior Basement Waterproofing in Ajax & Durham Region
Full excavation, waterproof membrane & new drainage tile — the gold standard fix for recurring leaks. Typical Ajax home: $8,300–$15,500.
The Permanent Fix: Water Never Touches Your Foundation
Exterior waterproofing stops water before it reaches your foundation wall — not after it's already inside. We excavate down to the footing, repair and seal the wall, apply a waterproof membrane, install new drainage tile in washed stone, and backfill with proper grading so water flows away from your home.
- Excavation to the footing — full exposure of the foundation wall, done with care around utilities and structures
- Wall preparation & parging — cracks repaired, surface smoothed so the membrane bonds perfectly
- Waterproof membrane — a continuous, sealed barrier over the entire wall (not just damp-proofing paint)
- New drainage tile & washed stone — replaces the clogged original weeping tile that caused the problem
- Proper backfill & grading — soil sloped away from the foundation so surface water never ponds against the wall
When Exterior Waterproofing Is the Right Choice
- Recurring leaks through wall cracks that keep coming back
- A failed or degraded exterior membrane on an older home (common in 1970s–90s Ajax builds)
- Clogged or collapsed weeping tile — the original drainage has given up
- Bowing or deteriorating foundation walls that need to be seen and addressed directly
- You want the most complete, longest-lasting solution available and the exterior is accessible
When it's not the answer: if a deck, driveway or addition makes excavation impractical or wildly expensive, an interior drainage system may be the smarter move. We'll show you both options with honest pricing at your free inspection.
Our Process
- Free inspection & fixed quote. We assess the wall, the water source, access for excavation, and what's sitting against the foundation.
- Utility locates & protection. Underground utilities are located and marked. Landscaping, walkways and structures near the dig are protected.
- Excavation. We dig to the footing in controlled sections — never exposing more wall than we can seal in a day.
- Wall repair & membrane. Cracks are repaired, the wall is parged, and the waterproof membrane is applied as one continuous barrier.
- Drainage tile & backfill. New weeping tile goes in on washed stone at the footing, then we backfill in lifts and re-grade away from the house.
- Restoration & walkthrough. The site is cleaned and restored as agreed, and we walk you through the lifetime transferable warranty.
Full exterior waterproofing typically takes 3–7 days including excavation and restoration, depending on how many walls are done and site access.
Typical Cost
Exterior waterproofing typically runs $150–$250+ per linear foot. For a typical Ajax home that usually means $8,300–$15,500 depending on depth, number of walls, soil conditions and restoration needs. It's the biggest investment of the waterproofing options — and the most complete. Your free on-site inspection gives you an exact fixed quote.
Exterior Waterproofing FAQ
Down to the footing — typically 7 to 9 feet for a full basement in Durham Region. That's the only way to seal the entire wall and replace the drainage tile where it belongs, at the base of the foundation.
Anything within the dig zone has to be removed or worked around — we'll map this out with you during the inspection and include restoration in your fixed quote. If excavation would destroy something you can't replace (or the cost doesn't make sense), we'll recommend an interior system instead and explain the trade-offs honestly.
A properly applied waterproof membrane lasts for decades — far longer than the tar-based damp-proofing used on most 1970s–90s homes, which is exactly what's failing now. Our exterior work is backed by our lifetime transferable warranty.
Frozen ground makes winter excavation difficult and expensive, so exterior work is typically scheduled from spring through fall. If you have an active leak in winter, call us — we can usually stabilize it with injection repair or an interior measure until a full exterior job is practical.
It's the most complete solution because water never reaches the wall — but "better" depends on your home. Interior systems are less disruptive, cost less, and fully solve many seepage problems. Exterior is the gold standard for recurring leaks and failed membranes. We'll recommend whichever one your situation actually calls for. Compare both in the FAQ.
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Fix It Once, Fix It Right
Free inspection, fixed written quote, lifetime transferable warranty. Serving Ajax, Pickering, Whitby, Oshawa & Scarborough.