Waterproofing Rooftop Plant Decks

A Guide to Liquid Applied Membranes for Efficient Roof Protection

There are challenges unique to flat roof surfaces that contribute to accelerated deterioration of the waterproofing system.

Unfortunately flat roofs can be inefficient in their ability to shed water – constant “ponding” water can present problems to membranes unsuitable for holding water.
Flat roofs also harbour more dirt & debris at joints, details and around penetrations such as service ducts and pipes.
All aspects of flat roof surfaces are constantly exposed to the full effects of external weathering.

Case Study: Severe cracks on existing roof membrane

Liquid waterproofing systems solve many of the challenges involved with flat roof projects.

These membranes can withstand ponding water.
Being liquid, they have the capacity to mould to the shape of the structure and around roof services.
UV stable and will not degrade in sunlight and importantly – unlike the older generation of roofing products – there are no naked flames on-site.
Cold spray-applied membranes provide fast application resulting in a robust barrier protecting against the effects of water, pollution, salt and chemicals.

Spray Applied Liquid Waterproofing

These new generation and state-of-the-art waterproofing membranes are a great alternative to the conventional bitumen roofing, EPDM, sheet and roll-on waterproofing products that have always exhibited many problems.
Elastomeric membranes create a uniform, monolithic and seamless waterproofing barrier.
The extreme flexibility of Liquid Applied Membranes (LAMs) allow for general building movement – the normal contraction and expansion of a roof structure – without the risk of membrane cracking.
Unlike adhesive or heat (flame) applied sheet membranes with joins, the fully bonded and seamless Liquid Rubber membrane prevents tracking and ingress of water underneath.

Liquid Rubber membranes were developed to address the recurring problems encountered by conventional membrane systems.
These products are state of the art and mindful of today’s environmental concerns and OH&S safe working practices.
Liquid Rubber it is cold applied, instant set and solvent free.
Liquid Rubber is a totally slump free system and suitable for both horizontal or vertical surfaces.

Seams & Joins: areas of weakness and major cause of water tracking.
Flames & Heat: conventional membranes (Torch On) can damage pipes, wiring & infrastructure due to heat applied during waterproof application.
Associated Fumes & VOCs: many conventional membranes i.e urethanes, vinyl and epoxy based coatings are high in VOCs (Volatile Organic Chemicals).
Cracking: conventional membranes harden over time developing cracks causing membrane failure.
Lack Adhesion: many conventional membranes are not fully bonded to the roof surface.

Leaking roof due to water pooling & tracking under sheet membrane.

After years of experience within the waterproofing industry, F.E.W Waterproofing have become advocates of the unique properties of Liquid Rubber.

Seamless: Liquid Rubber is spray applied producing a SEAMLESS membrane with superior adhesion.
Flexibility: Liquid Rubber has an elasticity of 800%(not age affected) and 95% memory.
Time: Fast spray application with rapid instant set curing – enables shorter windows of opportunity to carry out application.
Cold Spray Applied: Liquid Rubber does not require heat, flames or adhesives.
Eco-Friendly: Meets all OH&S concerns, non-hazardous, non-toxic & non-flammable.

The F.E.W Waterproofing team take great care inspecting all surfaces; these must be thoroughly clean prior to installing the waterproofing membrane.
A smooth, monolithic concrete surface is required for proper membrane adhesion – so all surfaces must be free of voids, spalled areas, loose aggregates, and sharp protrusions and with no coarse aggregate visible.
To ensure correct surface preparation we use high pressure washing, broom, vacuum cleaner and/or blown/compressed air to remove dust, loose stones, and debris.
After careful preparation, the concrete must be cured and dry before waterproof application can begin.
This surface was very porous so we applied a special environmentally friendly primer to reduce out gassing.

Spray applied Liquid Rubber over existing torch-on sheet membrane.