Interior vs Exterior Basement Waterproofing: Which Does Your Markham Home Need?

Choosing between interior basement waterproofing and exterior basement waterproofing is the most common decision homeowners face in Markham. Here's the framework we use.

Exterior basement waterproofing

The permanent fix. We excavate down to the footing, apply membrane and dimple board to the outside of the foundation, install or replace weeping tile, and re-grade. Stops water before it ever touches your foundation.

Best for: chronic wall seepage, foundation cracks, deteriorated old parging, finished basements where you don't want to lose interior space, anyone who plans to stay in the home long-term.

Interior basement waterproofing

We install a drainage channel along the perimeter of the basement floor, tie it to a sump pit, and manage water that does enter through the foundation. Fast, less invasive, more affordable upfront.

Best for: floor-wall joint seepage, situations where exterior excavation isn't possible (against a neighbour's wall, under a deck, near major landscaping), partial fixes when budget is a constraint.

When we recommend both

For severe chronic problems on accessible walls, doing both gives you maximum protection — exterior to keep water out, interior as a fail-safe.

What we'll NEVER do

Sell you an interior solution when we know exterior is what you actually need. If the source is wall seepage, interior alone is going to disappoint you in 3 years. We'd rather lose a job than do that.

Get a free inspection in Markham

If you've noticed dampness, cracks, or musty smells in your basement, don't wait. We offer free on-site inspections across Markham, Unionville, Cornell, Berczy Village, Cathedraltown, Markville and Thornhill — and our work is backed by a written workmanship warranty.