APP 4mm Torch-on Waterproofing Membrane, 1m x 10m Roll

APP Torch-on Membrane

The APP 4mm Waterproofing Membrane provides a high-performance barrier against moisture ingress for flat roofs, concrete decks, and foundations. This modified bitumen sheet utilizes atactic polypropylene to enhance thermal stability and resistance to ultraviolet degradation. It remains a standard specification for commercial and residential waterproofing projects requiring long-term structural protection.

Built for the Job

Contractors and site supervisors select this bitumen-based roll for applications where liquid-applied membranes may lack the necessary puncture resistance or thickness consistency. The torch-on installation method creates a physical fusion between the membrane and the substrate, ensuring that water cannot migrate beneath the layer even if localized damage occurs. This material withstands high ambient temperatures without flowing or losing its profile, making it suitable for exposed roofing environments. The internal non-woven polyester reinforcement allows the sheet to accommodate minor structural movements and thermal expansion without compromising the integrity of the watertight seal.

• Waterproofing of flat concrete roofs, balconies, and podium decks.

• Tanking for basement walls and subterranean structures to prevent damp.

• Protective lining for bridge decks and heavy-duty wet areas.

Product Highlights

Modified Bitumen Compound

The atactic polypropylene modification ensures the bitumen maintains flexibility at low temperatures while providing a high softening point above 120°C.

Polyester Reinforcement

• 180g/m² non-woven polyester core for high tensile strength
• Excellent elongation properties to resist mechanical stress

Technical Specifications

What’s Included

• 1 x 10m Roll of APP Modified Bitumen Membrane (4mm)

On-Site & Workshop Notes

• Substrate preparation is critical; ensure the surface is clean, dry, and free of sharp protrusions before unrolling the material.

• Always apply a compatible bitumen primer to the concrete deck to ensure maximum adhesion of the fused bitumen layer.

• Maintain a minimum side lap of 100mm and an end lap of 150mm to prevent moisture bypass at the joints.

• Store rolls in a vertical position on a flat surface to prevent core deformation and thinning of the bitumen compound.

• During torching, monitor the heat-sensitive film on the underside; a small bead of melted bitumen should be visible at the seam edge to confirm a successful bond.