Balcony Restoration & Repairs

Best Balcony Waterproofing Methods: Ensuring Structural Integrity and Efficiency

"There are leaking balconies all over Melbourne and the multi story apartment boom  is contributing to this defective housing crisis".

This unfortunate statement was taken from an article titled “Melbourne’s high-rise nightmares taking a toll on residents and investors” from The Age Melbourne 25th September 2016.

Read Original Article Here

Basement carpark - concrete leaching to ROOF water leaks.

Water damage from a leaking balcony above.

Leaking Balconies

There are several key points within this article I would like to emphasise:

  • Residential multi-story, multi-dwelling, apartment buildings are experiencing an alarming frequency of building defects, most commonly caused through waterproofing failure.
  • Balconies were identified as a major cause of waterproofing problems.
  • This has lead to the common assumption that for many multi-level balconies "proper waterproofing membranes are not installed."
  • The market has inconsistencies about Insurance cover, both from building trade cover and the residential owners cover. Resulting in the building owner necessitating to self-fund the corrections to the building.

Accumulation of calcium salts, known as “Efflorescence” occurs on balcony surfaces only in the presence of water.

Balcony repairs - complete strip out and major structural building works due to waterproofing failure and subsequent water leaks.

Balcony Design & Construction 

Construction Methods Change & Adapt

  • I have noticed recently, either for reasons of design and/or cost considerations, changes in balcony construction methods which have a direct impact on the success or otherwise of the waterproofing membrane.
  • Many balconies are currently being constructed with minimal falls to the substrate; particularly evidenced in multi-level apartments.
  • This design has a significant effect on the choice of waterproofing product, installation method and tile adhesives used.
  • The balcony membrane must be capable of “standing water”; as a balcony with minimal fall will have water ingress through the grout resulting in moisture “ponding” between the membrane and tiles.
  • If the membrane selected cannot withstand ponding water – and many of the market cannot - over time and together with the normal cyclic thermal contraction and expansion of a building, this will cause the membrane material to break down and/or joint failure and cause water leaks
  • Unfortunately, these issues are not always taken into consideration when contractors/specifiers/designers are deciding on waterproofing products and methodology for balconies.
  • This may result in the owners, investors and owners’ corporation having to face the challenges of solving future leaking balconies.

Balcony Waterproofing

Australian Standards & Drawings
For further information download

Drawings from MBAV - Balcony Design & Waterproofing Methods

Is the determination to push construction projects to meet demand a disaster in the making?

  • Experts warn that cutting corners to lower costs and meet targets are creating substandard homes and apartments.
  • Waterproofing failure, in particular balcony waterproofing, can lead to significant damage and even compromise the structural of the building envelope itself.

Balcony Collapse in Berkeley California Cause Six Deaths 

Many experts believe a balcony collapse that caused six deaths, due to exposure to water. 

See full article HERE

Factors Causing Balconies to Leak

In my experience, there are recurring issues causing waterproof failure:

  • Balconies and walkways are exposed to the destructive forces of the elements: ­ rain, wind, sunlight, and freezing conditions.
  • At the time of membrane installation if there is inadequate preparation &  detailing between the balcony to wall interfaces, water ingress will occur with  time.
  • Railing post and balustrade penetrations also requires detailed preparation to prevent water leaks.
  • As evidenced in the article above, developers & builders at the time of construction may use cheap (inferior) materials to save money.
  • There are many waterproofing products on the market, however professional waterproofing contractors will choose the best product for the individual project.

Best Balcony Waterproofing Method

  • The waterproofing product chosen should have comparable expansion capabilities as the balcony structure itself, strongly adheres all surfaces and create a permanent water tight bond around all balcony edges and surfaces.
  • Poorly detailed balcony surface transitions, interfaces and penetrations can lead to water ingress into occupied spaces below which in turn may lead to serious structural damage.

Fix Leaking Balconies  - Product & Installation

Successful remedial waterproofing system for leaking balconies:

  • All too often, penetration of water through the top balcony surface and exposed edges of both reinforced concrete balconies and timber framed balconies, leads to deterioration of the balcony structure and significant defects occur, such as concrete spalling.
  • Selecting the best waterproof product – selecting cost effective & long life membranes suitable for balcony design and the relevant conditions.
  • Correct membrane installation is just as important as product selection i.e. detailing to make water tight all balcony surfaces, interfaces, and penetrations.
  • Balcony waterproofing membranes must be capable of bridging cracks and joints of the underlying substrate, whether this cement sheeting, sycon board or others.
  • Membrane flexibility is an important criteria as the waterproofing will need to move with the normal contraction & expansion of the balcony envelope.
  • Balcony coatings with the ability to withstand “ponding” water.
  • Remedial waterproofing projects need fast & efficient installation - causing minimal disruption to building occupants.
  • Spray Apply Liquid Membranes are up to 3 x times faster installation compared with torch on & sheet membrane applications. 

Liquid Rubber Application

Spray Applied Liquid Waterproofing

Solvent-free, water-based building products offer immediate solutions to both safer worksites plus quality, high performance adhesives and protection. 

Liquid Applied Membranes are our preferred waterproofing product & method of choice for balcony repairs & restoration.

Melbourne -waterproofers

Balcony Waterproofing Without Removing Tiles

  • To give an opinion on remedial waterproofing works for balconies: re-grouting and surface sealing is not the way to repair a leaking balcony if it has been established there is a defective membrane.
  • This band-aid method may stop or slow down water leaks for a while – that is until the balcony moves and cracks the grout again and inevitably the balcony will start to leak all over again.


Balcony Repairs - Melbourne Builder & Certified Waterproofers 

Waterproofing Specialists & Registered Builders 

Commercial Waterproofing Installation & Applications

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