Foundation Waterproofing

Dampproofing controls soil moisture where drainage prevents water pressure. Waterproofing is a continuous system intended to resist water under hydrostatic pressure. The Ontario Building Code treats them differently. Harrowgate follows the applicable design and does not represent a thin asphalt coating as equivalent to a reinforced liquid or sheet waterproof membrane.

Exterior source-side work is generally preferred because it stops water before it enters the wall and allows drainage and protection to be rebuilt. Interior collection can manage water where exterior access is impossible, but it does not protect the outside face. The building, excavation constraints, structure, and leak path determine the solution.

Excavation normally exposes the complete below-grade wall to the footing or specified lower termination so the membrane can connect across the wall-footing junction and into drainage. Partial-height coating can miss the actual entry point. Depth, shoring, utilities, property limits, and groundwater are confirmed before the work zone is opened.

It protects the membrane from backfill damage and provides a vertical path for water to reach the perimeter collector. It is not a substitute for waterproofing and must terminate so soil cannot clog its drainage space. Product compressive capacity and fastening are selected for depth, backfill, and insulation detail.

Work is possible only when excavation, substrate, primer, membrane, drainage, backfill, and restoration can remain within approved temperature and moisture limits. Frozen walls, ice, snow, and frozen backfill are unacceptable. Temporary protection and heat can support some systems, but cure and condensation must be controlled.

Cracks are assessed for movement, structural significance, and active water. Treatment can include routing and flexible detail, polyurethane or epoxy injection under an engineered repair, cementitious rebuilding, and reinforced stripe membrane. Simply spreading field membrane over an untreated active crack creates a thin line that can reopen.

Provide foundation and site drawings, leak locations, wall construction, depth, utilities, property limits, grading, existing drains and sump, access restrictions, soil or environmental reports, and required restoration. Harrowgate uses test pits where needed to verify footing, membrane, pipe, and concealed constraints before final pricing.