Understanding waterproofing membranes for roofing

Fisheye shot of new apartments buildings

As a specialist waterproofer, Danrae Group is skilled in waterproofing solutions across strata, construction, civil and government … and in every style of structure.

That means we understand what factors will impact on your waterproofing in any location, which membrane is most suitable – and what brand will best do the job.

In the first of a series of blogs on waterproofing membranes, we take a look at waterproofing for roofing, and why the choice of membrane plays a major part in functionality – and longevity.

Waterproofing membrane basics

Waterproofing membrane basics

At the heart of every superior waterproofing solution is a quality membrane. A waterproofing membrane is a layer of material that forms a barrier against water penetration. It’s installed around building foundations to repel water and protect the building interior and structure.

Membranes come in two different forms: a liquid, such as water-based, solvent-based, cement based and bituminous based; or a sheet, which includes torch-on bitumen, PVC, Butynol or Peel and Stick, to name a few.

And depending on the project, waterproofers may layer them above or below a concrete screed and/or between insulation and floor coverings.

Each type of membranes has specific properties, making them suitable for particular property types, areas and environments. Membranes need to have robust waterproofing abilities and be sturdy enough to withstand natural building movement and external factors like chemicals.

Membrane considerations for roofs

Membrane considerations for roofs

When the Danrae Group team decides on the best membrane for a roof, considerations will include style of property and location. A commercial or strata building, for instance, will likely need to withstand more strain than a residential home.

And the shape of the roof is also significant. Flat roofs obviously do not drain as angled roofs do, so they are more susceptible to water pooling.

Both adequate drainage and the correct type of membrane are critical. Any water that fails to drain from a flat roof can leak into interiors or seep into building foundations, potentially leading to issues such as concrete spalling and concrete cancer.

At Danrae Group, we design bespoke waterproofing solutions that also take into account roof usage. Our choice of membrane has varied for jobs ranging from inner-city apartments with a rooftop swimming pool and tennis court to a major hospital needing efficient waterproofing to protect sensitive equipment in a top floor clinic.

Best choice membranes for roofing

Best choice membranes for roofing

While every waterproofing roof project is distinct, our team would generally look for a membrane that has UV and heat-reflective properties. Options and benefits include:

  • Elastomeric sheet (PVC, TPO, Butynol or rubber): flexible, durable, uniform thickness, root-resistant, UV stable, heat-reflective, can be laid over damp substrates and is compatible with PVC fittings and downpipes.
  • Torch-on modified bitumen – guaranteed membrane thickness, two layers thick, long-term durability, UV stable, vapour distribution base sheets, root-resistant.

Sheet membranes can be the most costly type of membrane but have a lifespan of up to 50 years.

Leading the way with waterproofing for roofing

Leading the way with waterproofing for roofing

Membranes are not fit-all solutions, which is why the best roofing plan will come from a team experienced in tailored waterproofing solutions.

At Danrae Group, our waterproofers are trained in every waterproofing technique and every type of membrane. And we have builders, carpenters and other tradies in-house.

With vast capability at hand, we oversee every project from concept to completion. So, if you need quality and efficient waterproofing for your roof, please get in touch. Read more articles about membrane waterproofing.

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