Choosing the Right Waterproofing System

Selecting the right membrane isn’t about brand—it’s about site, substrate, detailing, and lifecycle.

🔥 Torchon (Bituminous)

Best for: Concrete or plywood decks/roofs.

Pros: Multi-layer strength, great at complex details, long track record. Watchouts: Requires flame, adds heat/weight, and can run hotter in summer.

🌿 TPO (Thermoplastic Polyolefin)

Best for: Large low-slope roofs.

Pros: UV-stable, light-coloured, clean heat-welded seams, fast to install.

Watchouts: Edge and penetration detailing must be precise; substrate flatness matters.

🧴 Liquid-Applied Membranes (PU, PMMA)

Best for: Complex shapes or flame-free sites.

Pros: Fully bonded, seamless, perfect for transitions and refurbishments.

Watchouts: Prep is critical; corners and outlets must be reinforced properly.

Warm Roofs vs Cold Roofs

Type	Description	Pros	Cons
Warm Roof	Insulation above structure, membrane on top	Reduces condensation, stable substrate, longer life	Higher upfront cost
Cold Roof	Insulation below deck	Lower cost	Higher condensation risk, more movement

👉 Our take: On Auckland’s low-slope roofs, a warm roof usually pays off over time.

For decks over living areas, get your falls right at the structure level—the membrane can’t fix poor geometry.