Liquid Membrane Waterproofing

Step 1, Harrowgate creates a continuous liquid membrane through disciplined substrate preparation and film control. We complete every detail before the open field, maintain wet edges and coverage, verify cure and integrity, then install protection and drainage without puncturing the finished barrier.

Step 2, Substrate assessment and repair. Concrete is checked for laitance, fins, bugholes, honeycombs, cracks, curing compounds, oil, moisture, and sharp changes. Unsound material is removed, holes and recesses filled, high points ground, and compatible slope repairs completed. Masonry receives parging where required so liquid material is not expected to bridge deep joints and voids.

Step 3, Primer and adhesion confirmation. Primer is selected for concrete, wood, metal, old membrane, or other approved substrate and applied at controlled coverage without puddles. Porous areas may need additional treatment. Test patches confirm wetting and bond, especially on repair mortars and transitions. Primer is membrane-system material, not a generic bonding agent.

Step 4, Crack and detail reinforcement. Cracks, cold joints, corners, wall-to-footing angles, drains, sleeves, curbs, and terminations receive stripe coats, fabric, fleece, sealant, cants, or preformed accessories. Reinforcement is embedded without wrinkles and extended beyond the stress line. Active expansion joints use a designed movement system separate from the field membrane.

Step 5, Field membrane application. Self-levelling grades are spread on horizontal work, roller or squeegee grades serve open decks, non-sag materials serve vertical surfaces, and spray equipment suits large areas where approved. Crews monitor material temperature, batch time, weather, wet edge, and wet-film thickness. Multiple coats use contrasting colours where helpful for coverage.

Step 6, Testing and repairs. After cure, the surface is reviewed for pinholes, thin spots, blisters, contamination, and damaged details. Horizontal assemblies can receive a 50 mm water head for 24 hours where flood testing is specified and structurally permitted. Electronic or other integrity testing is used where compatible. Repairs are retested before cover.

Step 7, Protection and overburden. Drainage mat, protection board, insulation, asphalt, concrete topping, pavers, soil, or traffic wear courses are installed only after membrane cure and acceptance. Temporary access uses load-spreading protection. Fasteners, stakes, and stored reinforcement are excluded unless the detail specifically provides for them.

Step 8, Application records include substrate conditions, repairs, primer, product lots, weather, area, material quantity, wet-film checks, cure, test results, and mapped repairs. Harrowgate photographs drains, penetrations, joints, and terminations before protection. Overburden handoff identifies allowable equipment and access routes so the accepted membrane remains intact through later work.