Repair Systems — Single-Ply Sheet Membranes
Single-ply sheet membrane systems — roofs and podiums
Technical product reference for single-ply polymeric sheet membrane systems used in roof deck, podium slab, and large terrace waterproofing remediation on Australian Class 2 strata apartment buildings — PVC sheet membranes, FPO/TPO sheet membranes, HDPE-bentonite composite systems, and specialist applicator requirements.
What are PVC / HDPE single-ply sheet membrane systems?
This category covers factory-made single-ply sheet systems — flexible PVC roof/podium membranes (loose-laid, self-adhesive or mechanically fixed) and HDPE-bentonite composite sheets for below-grade tanking. They are specified, accredited-applicator systems with welded or bonded laps and (for the PVC systems) long manufacturer warranties. Selection turns on the duty (exposed roof vs below-grade), install method, reinforcement, and the Class 2 (NCC) test evidence to AS 4654.1.
Class 2 (NCC) — balconies, roofs & podiums: specify only a sheet with current Australian test certification (see the “Class 2 / NCC tested” field on each card). EN 13956 / CE marking is European, not an Australian certification.
Product Reference
Individual products — one card each — scroll to view all
Wolfin / Projex Group
Wolfin IB — Loose-Laid PVC Sheet Membrane
Polyester-PVC single-ply sheet — loose-laid, mechanically fixed
Wolfin IB is a German-engineered polyester-PVC single-ply waterproofing sheet, loose-laid and secured with mechanical fixings, for roofs and podiums. NATA-tested in Australia and compliant to AS 4654.1-2012 and AS 4858. Sole Australian distributor Projex Group; installed only by Projex-accredited applicators, with an inspected single-point warranty of up to 20 years on workmanship and materials.
Wolfin / Projex Group
Wolfin GWSK — Self-Adhesive Bonded PVC Sheet Membrane
Polyester-PVC single-ply sheet — cold self-adhesive bonded
Wolfin GWSK is a 2.3 mm homogeneous, reinforced, cold self-adhesive (bonded) polyester-PVC waterproofing sheet with an integrated special glass fleece, bitumen-compatible, for roofs and podiums. NATA-tested and compliant to AS 4654.1-2012. Sole Australian distributor Projex Group; Projex-accredited applicators only; single-point warranty up to 20 years on workmanship and materials.
Cosmofin / Projex Group
Cosmofin FG / FG LL — Reinforced PVC Single-Ply Sheet Membrane
Reinforced flexible PVC single-ply sheet (1.5 mm)
Cosmofin FG / FG LL is a 1.5 mm reinforced flexible PVC single-ply membrane (light grey), engineered in Germany by Wolfin, available with or without fleece backing for bonded, loose-laid, ballasted or mechanically-fixed installation. NATA-tested and compliant to AS 4654.1-2012 and AS 4858. Projex Group sole Australian distributor; accredited applicators only; single-point warranty up to 20 years.
Sika Australia
Sika Sarnafil G 410 — PVC Single-Ply Sheet Membrane
Multi-layer PVC single-ply roof sheet (hot-air weldable)
Sika Sarnafil G 410 is a multi-layer synthetic PVC roof waterproofing sheet with a glass non-woven inlay, hot-air weldable and UV-stabilised for direct exposure, available 1.5 mm (G 410-15 L) and 2.0 mm (G 410-20 L). The AU page cites EN 13956 / GB 12952; confirm the current Australian AS 4654 certification and accredited applicator with Sika Australia.
Tremco Australia
Tremco Paraseal LG — HDPE-Bentonite Composite Sheet Membrane
HDPE-bentonite composite sheet — below-grade tanking
Tremco Paraseal LG is a below-grade tanking sheet — 20 mil high-density polyethylene laminated to expandable granular bentonite with a spun-bonded polyester protective layer. The bentonite swells up to 8× to self-seal; the HDPE provides ≈180 kg/m² puncture resistance. For blindside/lagging walls, under-slab and elevator pits. A below-grade system — AS 4654.1 (external above-ground) does not apply.
System Comparison
PVC / HDPE single-ply sheet systems — confirm all selections against the current manufacturer TDS before specifying.
Scroll the table sideways to see every column →
SINGLE-PLY SHEET MEMBRANE INSTALLATION REQUIRES SPECIALIST ACCREDITED APPLICATORS — DO NOT SPECIFY WITHOUT CONFIRMING APPLICATOR AVAILABILITY
Hot-air welding of PVC and FPO/TPO single-ply sheet membranes is a specialist skill requiring calibrated welding equipment, manufacturer training, and verified installation experience. An improperly welded seam — incorrect weld temperature, speed, or pressure — may appear visually continuous but will fail under hydrostatic pressure and thermal cycling. Both Projex Group (Wolfin, Cosmofin) and Sika (Sarnafil) require installation by their accredited applicator networks and provide single-point warranties on workmanship and materials only through accredited installations. Do not specify single-ply sheet membranes without first confirming that a manufacturer-accredited applicator is available and accessible for the project location and programme. Accredited applicators are not available in all locations — confirm before specifying.
ALL HOT-AIR WELDED SEAMS MUST BE TESTED BEFORE ANY COVERING LAYER IS INSTALLED
Every hot-air welded seam on a single-ply sheet membrane installation must be tested for continuity before the protection board, drainage layer, growing medium, ballast, or paver system is installed above. Point probe testing and air lance testing are the standard seam test methods for PVC and FPO/TPO membranes. A seam that fails testing can be repaired by re-welding and re-testing before covering. A seam that is covered without testing and subsequently leaks requires full removal of all covering layers to access and repair — at significant cost. Seam testing is mandatory, not optional, on all Class 2 strata podium and roof deck remediation projects.
PVC MEMBRANES MUST BE SEPARATED FROM BITUMEN AND INCOMPATIBLE MATERIALS
PVC sheet membranes contain plasticisers that can migrate into and be extracted by contact with bituminous materials, coal tar, oils, and certain solvents. This plasticiser migration accelerates PVC degradation and can reduce the service life of the membrane. Where a PVC single-ply sheet membrane is installed over or adjacent to an existing bituminous membrane, screed, or surface treatment, a compatible separation layer must be installed between the PVC membrane and the bituminous material. Confirm the required separation layer type and thickness with the membrane manufacturer (Projex Group or Sika) before installing. Wolfin GWSK has a bitumen-compatible self-adhesive layer specifically designed for bonding over existing bituminous surfaces — confirm with Projex Group whether a separation layer is still required in specific circumstances.
DO NOT CONFUSE HDPE-BENTONITE COMPOSITE MEMBRANES WITH PVC AND FPO SINGLE-PLY ROOF MEMBRANES
HDPE-bentonite composite sheets (such as Tremco Paraseal LG) are below-grade waterproofing products — they require confining pressure from overburden or structural concrete to activate and maintain the bentonite seal. They are not UV stable and are not designed for exposed roof deck, podium surface, or above-grade applications. The tab title references HDPE sheet membranes, but the primary single-ply products used on Australian roof decks and podium slabs are PVC and FPO/TPO sheet membranes — not HDPE-bentonite composites. Select the correct product type for the application: PVC or FPO/TPO for exposed roof and podium; HDPE-bentonite for below-grade and subsoil.
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, substrate condition, drainage design, structural loading, wind uplift design, AS 4654.1 and AS 4654.2 requirements, NCC requirements, and waterproofing consultant advice. Single-ply sheet membrane installation requires manufacturer-accredited specialist applicators — do not specify without confirming accredited applicator availability. All hot-air welded seams must be tested before covering. Do not rely on this reference as a substitute for professional waterproofing consultant or structural engineer advice.