Sheet and Torch-On Waterproofing Scarborough

Step 1, Harrowgate builds sheet waterproofing from a smooth compatible substrate through sequenced rolls and closed seams. We plan sheet direction, stagger joints, reinforce details, inspect every lap, terminate the membrane mechanically or within the designed assembly, and protect it immediately after acceptance.

Step 2, Substrate and layout planning. Concrete fins, holes, honeycombs, laitance, sharp corners, old bitumen, oil, and moisture are corrected before priming. Sheet widths and roll lengths are planned around drains, corners, slopes, and access so end laps do not cluster. Work begins at the low point or designed drainage sequence and maintains positive shingle laps where applicable.

Step 3, Primer and detail sheets. Compatible primer is applied evenly and allowed to reach the required tack. Corners, cracks, construction joints, wall-footing lines, drains, pipes, and terminations receive pre-cut reinforcement or flashing sheets. Inside and outside corners are formed without fishmouths, and relief cuts are covered by the required additional layer.

Step 4, Self-adhered sheet placement. Release film is removed progressively while the sheet is aligned without stretching. The membrane is pressed from centre outward and rolled firmly, especially at side and end laps. Air pockets, wrinkles, and contaminated adhesive are cut out and patched with the required extension beyond the defect. Cold-weather grade and primer follow approved limits.

Step 5, Torch-applied placement. For approved hot-work areas, the substrate and rolls are staged under the project hot-work controls. Heat is applied uniformly to the roll and substrate to produce the specified melt and continuous bitumen bead without scorching reinforcement or overheating the sheet. Seams are offset between plies, and sensitive substrates receive the designed separation or base layer.

Step 6, Seams, terminations, and penetrations. Side and end laps follow the approved width, with end joints staggered. T-joints are rolled or heated carefully to avoid capillary openings. Upper edges use termination bars, counterflashings, reglets, or protected transitions. Pipe collars, drain flanges, curbs, and expansion joints connect to compatible manufactured or reinforced details.

Step 7, Inspection, testing, and protection. Seams are probed after cooling where appropriate, and surfaces are reviewed for blisters, fishmouths, voids, punctures, and exposed reinforcement. Flood or electronic testing is completed where specified and compatible. Protection board, drainage composite, cover board, pavers, asphalt, concrete, or soil is installed without dragging across exposed sheets.

Step 8, Harrowgate records sheet type, lot, primer, lap dimensions, weather, substrate, seam method, detail locations, inspection, and repairs. Photographs capture T-joints, corners, drains, penetrations, and terminations before protection. Hot-work documentation and final fire checks are completed under site requirements, and overburden crews receive protected access routes and fastening restrictions.