Waterproofing (tanking) work conducted by Flex A Seal in Melbourne


Flex A Seal Tanking Systems are designed to contain hydrostatic water pressure and are specifically installed to prevent water entry or egress.

These are some of the most prevalent structures we tank:-

o Retaining building and garden walls

o Suspended or freestanding swimming pools

o Feature and organic ponds

o Water storage tanks

o Planter boxes

o Combined underslab / retaining wall installations





The success of tanking retaining wall structures and planter boxes depends on three factors:

1. Effective tanking installation where the foundation and retaining walls join.

2. The correct location of agricultural pipes in relation to the height of the retaining structure.

3. Using the right filtration material to fill in the trench between the retaining wall and the battered excavation, once the tanking installation is in place.

Flex A Seal can assist in providing advice and contracting services to carry out anyone or all of the above works.

Flex A Seal provides positive and negative tanking systems. The later is often referred to as ‘retrofit systems’ and are applied to the inner side of the retaining walls. Our versatile range of tanking systems enables us to provide effective solutions where design criterion conforms to our safety and installation methodology.

All our “external tanking systems” include the installation of a protective layer that prevents tanking membranes from possible damage during backfilling or certain drainage filtration installations.





Flex A Seal’s specific multilayered tanking systems are fit for use as an exposed system or covered by cladding, cement render, or tiles.

We only offer tanking systems that are inert, ensuring potable water will not be contaminated or discoloured.

Our feature pond and swimming pool tanking systems can be finished in a variety of colours, most of which are UV stable.

For reflection or organic ponds, however, we recommend black or black/green as the most suitable algae growth-retarding colour scheme.

All of Flex A Seal’s tanking systems integrate well with commonly available proprietary wall renders and tile adhesives.

Our meticulous installation techniques have resulted in many successful tanking installations that have been in service for well over twenty years.



Bathroom waterproofing work conducted by Flex A Seal in Melbourne.

Internal Wet Areas

Waterproofing bathrooms IS OUR OLDEST DISCIPLINE. Our waterproofing membranes have been installed in countless bathrooms throughout Melbourne and beyond.

How Our Waterproofing Membranes Are Installed

The first step of waterproofing internal areas is the application of a graded cement floor screed. A three-layered membrane is then installed.

Our carefully installed waterproofing membrane is designed for maximum flexibility. All aspects of our installations, including shower wall niches, windows, and ledges are meticulously detailed to ensure they are waterproof and easy to tile. Flex A Seal’s internal wet area (IWA) membrane systems can be easily tiled over using generic compatible tile adhesives.

Tilers are our partners and our men love it when a tiler that is new to us compliments our work because we made his job easier.

General Internal Wet Area Waterproofing Scope

We can waterproof bathroom, laundries, and powder room floors, and bath frames, including around all relevant fittings.

All shower walls and bath splashbacks are waterproofed to a minimum height of 100mm above the showerhead or faucets. General bathroom, laundry, and powder rooms are waterproofed to form an impervious tray a minimum 70mm in height, with reinforcements to the waterproofing membrane applied to all joints and corners.

True to our name, all our membranes are installed so they remain flexible, an important feature with today’s light-weight construction methods.


Flex a Seal waterproofing project in Kew, Melbourne

Our Waterproofing Membrane Systems Are Made Of The Best Materials

To deliver the best in performance, our systems are made of the highest quality materials, namely CLASS 3 Latex-based membrane emulsions with an elongation factor of 300%, exclusively manufactured to achieve our desired standards. By the way, CLASS 3 means the membrane, once cured, will never emulsify which is, invariably, not the case with standard acrylic membranes.

All our installations are compliant with current Australian Building Standards: A.S.3740 and Building Code Australia: B.C.A. Vol.2 Part 3.8.1.

As part of our services, Flex A Seal’s pre-works inspections or tender submissions based on quantitative assessments from architectural plans is followed by the quality-assured installation schedule with a Certificate of Compliance issued by Flex A Seal to the procurer. The certificate is transferable to current or future building owner[s].

All our waterproofing installations are supported with a peace of mind, Ten Year Performance Warranty.


Flex a Seal waterproofing project in Kew, Melbourne

Balcony waterproofing project conducted by Flex A Seal in Melbourne

Terrace, Deck & Balcony


Flex A Seal’s waterproofing for terraces, decks and balconies (TDB) comprises of two distinct systems designed to satisfy the most diverse spectrum of construction methods.

Flex A Seal Composite TDB SYSTEM 1


This system is generally applied to concrete floor structures or light weight structures on compressed cement sheet flooring. The installation of a graded cement screed is followed by the application of a reinforced, fully detailed, three-coat synthetic rubber waterproofing membrane. Tiles, pavers or tiling can be placed directly onto the membrane.


  • No mineral salt migration from the supporting graded screed to the tiled finish.
  • Maximum efficiency for tile installers as the substrates are accurately pre-graded and the waterproofing installation is professionally completed.
  • Flex A Seal’s waterproofing membrane installations are installed according to professionally engineering standards backed up by our in-house quality check system.

Flex A Seal Composite TDB SYSTEM 2

DSC00189This system caters for lightweight and solid constructed terraces, balconies or decks that require maximum protection due to extreme atmospheric exposure, built-up systems (e.g. roof gardens) or a variety of unique design criterions.

Flex A Seal’s composite TDB System 2 comprises of various reinforced and unreinforced, polymerised and pliable PVC sheet membranes. These are assembled using profiled flashings, angles, and preformed corners, and then joined by a welding process where each seam is progressively tested.

The system is typically installed onto a pre-graded substrate. Upturning terminations can be integrated to suit any wall finishes.

Flex A Seal teams install versions of this system that are loose-laid or adhered to the substrate. For exposed systems, we secure the membrane with concealed mechanical fixings during the installation to protect against the effects of possible “wind suction”.

Flex A Seal’s TDB SYSTEM 2 can be extended and incorporated as a continuous tanking system for swimming pools, retaining walls, or planter boxes.

Why Choose Flex A Seal?


Our waterproofing membrane systems have been developed and proven to be effective in hundreds of installations that have been in service for more than 30 years.

Our team is well equipped to advise and implement suitable waterproofing solutions for your project, be it for a new or remedial project.

We also welcome designers that wish to engage our services to develop specific waterproofing solutions for architecturally demanding designs that may require “outside the square” thinking.

Our highest propriety is that our solutions for waterproofing terraces, decks and balconies will be effective.