Thornhill Bungalow: Full Exterior Membrane Installation, Step by Step

Some homeowners want to understand exactly what they're paying for. We love that. Here's a full walkthrough of an exterior basement waterproofing job we completed on a 1960s Thornhill bungalow last fall.

Step 1: Locate utilities and stake the dig area

Before any shovel touches dirt, we mark every gas, hydro, water, and telecom line. Then we stake the excavation perimeter and lay plywood paths to protect the lawn.

Step 2: Excavate to the footing

We dig down to the bottom of the foundation footing — typically 6 to 8 feet — along the entire affected wall. For this Thornhill home, that was a 32-foot run.

Step 3: Clean and prep the wall

We pressure-wash the foundation, let it dry, and inspect for cracks, voids, and old parging that needs to come off. Any visible cracks get injected with polyurethane before we membrane over them.

Step 4: Apply rubberized membrane

A heavy-duty rubberized waterproofing membrane goes on the entire wall, trowelled or sprayed to a consistent thickness, with extra at corners and at the wall-footing joint.

Step 5: Install dimple board

A high-impact dimpled drainage board covers the membrane, creating an air gap so any future groundwater drains down to the weeping tile instead of pressing against the wall.

Step 6: New weeping tile

We install fresh perforated drainage pipe at the footing, wrap it in filter cloth, surround it with clean drainage gravel, and tie it into the existing drainage or sump pit.

Step 7: Backfill and re-grade

Clean gravel goes back first, then native soil in lifts, then we re-grade the surface to slope away from the home — at least 6 inches of fall over the first 10 feet.

Step 8: Restore the surface and clean up

Sod, mulch, or whatever was there before — restored. Driveway and walkway pressure-washed. Lifetime transferable warranty paperwork left on the kitchen counter.

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.