Liquid Membrane Waterproofing

Many cold-applied protected systems are specified around 1.5 mm dry thickness, while traffic, hot-applied, and specialized systems can differ. Solids content means wet and dry film are not always equal. Harrowgate checks wet-film gauges, measured area, and material yield against the approved Canadian assembly rather than judging thickness by colour.

Only products specifically approved for that substrate condition can be used, and damp is different from active leakage or standing water. Many membranes require dry concrete and controlled vapour. Harrowgate reviews product limits, tests suspect areas, controls water, and does not use extra primer as a substitute for acceptable substrate moisture.

Cracks are assessed for width, movement, structure, and water. Small dormant cracks can receive routed sealant and a reinforced stripe coat, while active structural or expansion joints need engineered treatment. The detail extends beyond the crack so movement is distributed before the full field membrane is applied across it.

Testing begins only after the membrane reaches the cure specified by the manufacturer and details are complete. Where the structure and drains permit it, a common procedure uses roughly 50 mm of water for 24 hours. Leaks are mapped, repaired under the approved process, and retested before protection is installed.

Cold liquid systems cure from polyurethane, polymer-modified bitumen, acrylic, or reactive resin and can serve vertical, horizontal, exposed, or protected uses depending on product. Hot rubberized asphalt is heated and applied as a thick protected monolithic membrane, commonly on plazas, podiums, and protected roofs. Each needs its complete system.

Protected below-grade and overburden systems do. Protection board or drainage composite prevents puncture during backfill, concrete topping, pavers, soil placement, and later work. Exposed traffic systems instead use compatible wear coats and topcoats. Harrowgate installs the protection specified for the actual load and construction sequence.

Provide plans, details, membrane system and thickness, substrate, repair scope, cracks and joints, penetrations, drains, slopes, vertical turn-ups, testing, protection, drainage, overburden, weather limits, and phasing. Harrowgate calculates detail and field quantities separately so corners, reinforcements, and transitions are not hidden inside a generic area rate.