Monolithic Cladding 101 And it’s Contributions Towards Leaky Homes – Part One


Leaky Homes – $11.3 Billion Dollars later!

– If Monolithic Cladding is to Blame Why Is it Still Being Used Today?


I met up with my brother-in-law Matt,  he’s carrying out an extension on a house, which is using the Monolithic cladding.

He was telling me the job has blown out from a 6 week job to 12. You could tell his blood was boiling as he was explaining the frustrations he and his team were having applying it to the new extension. “Ain’t no water getting into this house!” he grunted.

So after that brief conversation, it looks to me like the engineers, architects, manufacturers and who ever else have all come to the party and tightened up specifications.

Leaky Homes Crisis — It’s cost this country 11.3 billion dollars in total and tax payers 25% of that. But is it going to cost us any more and why are we still using Monolithic Cladding?

With changes to the Real Estate Code of Conduct, which came into force on the 8th April, licensees will most likely be asking home sellers to provide independent reports for anything that may look like it has defects especially weathertightness, to ensure there’s no confusion between all parties and that the onus lies with the seller.

It’s also partly to blame for the liquidation of Mainzeal and the loss of hundreds of jobs across the country. However Mainzeal also says it had the downturn to blame as well.


Monolithic Cladding! Lets try and understand it with an easy-to-understand definition.

The Best Definition Of Monolithic Cladding I Could Find!

Fibrous cement sheets applied together giving the impression of seamless and continuous coverage to the outside walls of the property.

According to the, the definition of  ’Monolithic’ cladding is:

“A cladding of sheet material forming a continuous mass, with an applied coating to give the appearance of a seamless cladding”

Other definitions of Monolithic Cladding:


A Brief History Of Leaky Homes!

It was the popular plaster coated monolithic clad homes that were letting water into the wall cavity and not allowing it to get out again.  As opposed to standard weatherboard homes, which have an airspace in behind and below for drainage and drying.

Moisture would become trapped inside of the wall and because of poor sealing standards at the time and lack of flashings to windows.

In 1997 the law changed around untreated timber being allowed to be used in homes. The timber used, no longer needed to be treated with Boron (prevention of borer). That same treatment improved the resistance of rot, so it was really a combination of these two things that amounted to a lethal dose that effected a nation.

2002 the Government commissioned, what is known as the Hunn report, to investigate the issues of leaky homes, which speedily resulted in a change to the Building Act 2004.  As a result we now use monolithic cladding with an air-cavity, allowing for proper drainage as  well as properly treated timber.  The government – at the same time – set up the Weathertight Homes Tribunal for claims of compensation.

After a swath of litigation for repair claims against local councils for issuing code of compliance certificates from negligent inspections. The Government then commissioned Price Waterhouse Coopers (PWC) in 2009, in which  damning evidence uncovered by of the investigation exposed an estimated repair bill of $11.3 Billion for 42,000 effected homes.

A Financial Assistance Package in 2011, was set up by the Government for leaky homes, in which they contribute 25% to approved repairs.

  Typical Example Of A Monolithic Leaky Home


Watch Our Video Below To See A Typical Example Of A Leaky Home

Technical Side In Layman’s Terms

The image below  tells the story of how the cladding system used to fail before the new water proofing systems were brought into place. As you can see the moisture build up around the flashing area and in between the plaster finish and Monolithic backing. There’s nowhere for the moisture to drain. 

The second image is a modern cavity system, which is used on all monolithic cladding systems. It allows any moisture that gets into cladding system to escape without causing any damage to any of the building materials. The addition of a cavity battern allows for drainage and the waterproof underlay prevents moisture from getting in. 



Monolithic Cladding 101 And it’s Contributions Towards Leaky Homes – Part Two

Will delve a bit deeper into the different types of Monolithic cladding:

    • Stucco


    • EIFS (“Chilli Bin”)


    • Fibre-cement sheets (“Harditex”)



…as well as exploring a bit more of the leaky homes saga and how to understand the changes we’ve made through the 4d’s system.
    • Deflection


    • Drainage (the cavity concept)


    • Drying


  • Durability

We’ll describe what to look for, prevention and maintenance methods and other resources to help guide through this complex area.