Foundation Waterproofing Cost in BC

Average cost

Exterior foundation waterproofing in the Lower Mainland usually costs $15,000–$40,000 for a detached home when done with excavation and new drain tile. Adding membrane while drain tile is already being replaced typically adds $4,000–$10,000.

Cost per square foot

Membrane and drainage board typically cost $8–$20 per square foot of wall, installed, on top of excavation.

Excavation costs

Excavating to footing depth usually represents half or more of the cost — the membrane itself is a smaller share.

Landscaping restoration

Expect $2,000–$10,000+ for restoring walkways, patios, planting and lawn.

Accessibility

Tight side yards, decks and additions over the foundation increase cost or force partial exterior/interior solutions.

Depth

Full-height 7–8 ft basement walls take more membrane and excavation than partial basements.

Permits

Most Lower Mainland municipalities (Vancouver, Burnaby, Surrey, Richmond and others) require a plumbing permit for perimeter drain replacement and any new storm connection. Permit and inspection fees typically add a few hundred dollars. Your contractor should pull the permit and hand you the final inspection sign-off.

Membrane type

Damp-proofing (tar-type coating) is cheapest but only resists moisture. Rubberized or sheet membranes with dimple drainage board are true waterproofing and cost more.

One wall vs full perimeter

Waterproofing a single leaking wall ($5,000–$12,000) can make sense, but water often moves to the next weak point. Pair it with new drain tile when the tile is also old.

Vancouver vs Fraser Valley considerations

Vancouver, Burnaby and New Westminster jobs tend to cost more: tight lot lines, shared side yards, mature trees, hand digging and higher disposal and parking costs. Fraser Valley jobs (Langley, Abbotsford, Chilliwack, Maple Ridge) usually have better machine access and lower disposal costs, but larger homes, longer runs and heavier clay can offset the savings. Low-lying Richmond and Delta often add dewatering and sump work.

Questions to ask contractors

1. Is this damp-proofing or true waterproofing membrane?
2. Will drainage board and new drain tile be included?
3. How will cracks and tie-rod holes be sealed before membrane?
4. Does the quote include restoration and permits?
5. What is the warranty on the membrane?

When foundation waterproofing is actually necessary

Exterior waterproofing is worth it when you're already excavating for drain tile, when water pushes through foundation walls, or when finishing a basement.

Learn more about foundation waterproofing in the Lower Mainland.