Flat Roof Waterproofing

Why flat roofs need a different approach

Low-pitch roofs, balconies and podium decks rely on a continuous waterproof membrane rather than overlapping tiles or sheets. When that membrane cracks, lifts or blisters, water can travel underneath and appear well away from the original fault. Most problems we see trace back to poor falls, blocked outlets or tired detailing around upstands and penetrations.

Systems we install

We choose a membrane based on the substrate, roof traffic and how the building is used:

• Torch-on membranes – tough, two-layer bitumen sheets suited to concrete roofs with plant and service traffic.
• Liquid-applied membranes – seamless coatings that handle complex shapes, balconies and lots of penetrations.
• Reflective coatings – used over sound membranes to reduce heat build-up in summer.

Fixing the cause, not just the surface

A new membrane on a roof that still holds water will age early. Before we waterproof, we look at how water leaves the roof. That can mean building up screeds to create proper falls, enlarging sumps, adding overflows so a blockage cannot flood the building, or upsizing rainwater heads that cannot cope with summer storms.

Commercial and residential work

Much of our flat roof work is on Canberra offices, shops and apartment blocks, where we work with property managers and plan around tenants. We also waterproof residential balconies and decks above living areas, where a small failure can damage ceilings below.

Each job finishes with a written record of the system used, photos of key details and a maintenance checklist so outlets stay clear between inspections.