Waterproofing is under the microscope in New South Wales, especially for new strata builds. Research from the NSW Building Commissioner has revealed waterproofing is the most common serious defect found in class 2 residential apartment buildings (September 2021).

As part of the Construct NSW strategy, the research was a joint project by the Office of the Building Commissioner and the NSW Strata Community Association.  A survey asked 1,400 strata managers to nominate serious defects found in buildings of four storeys or more, built within the past six years.

Serious defects in NSW strata buildings

According to the Research report on serious defects in recently completed strata buildings across New South Wales, 39% of strata buildings in the survey had experienced one or more serious defects in the common property. Of the buildings with defects, more than half (63%) included waterproofing as one of the defects.

Across all class 2 residential apartment buildings in the survey sample, the following serious defects were reported:

  • Waterproofing – 23%
  • Fire safety systems – 14%
  • Structure – 9%
  • Enclosure – 9%
  • Key services – 5%
  • Non-compliant cladding – 6%

Most of these defects were identified through independent expert advice which had been commissioned by the owners corporation. Only half of the defects had been resolved at the time of the survey.

Getting waterproofing right

Based in Sydney, Gary Bennett is a Fosroc ANZ specification manager. He spends a lot of time supporting designers with waterproofing product system options for new builds, which he calls "getting it right the first time”. He also helps with remediation solutions after inadequate waterproofing has failed.

Some of the common waterproofing defects he sees in strata builds are:

  • apartment balcony leaks
  • planter boxes and roof gardens leaks
  • efflorescence (powdery mineral deposits on building surfaces).

Asset owners, engineers and architects, and builders and waterproofing contractors all play a critical role in preventing problems before they happen.

"Waterproofing is a high risk, high value part of the construction industry, so it does require serious attention to detail from all parties," Gary says. "The product systems, the design and the application all require 100% input. If you get waterproofing 99% right, it is a failure.”

Looking ahead

Since September 2020, NSW Fair Trading has been auditing all class 2 buildings, usually during the last six months of construction. In a full year of Occupation Certificate (OC) Audits, the incidence of waterproofing defects was 29% lower than in the Building Commissioner's research.

It's hoped that this is a sign the audit program, together with significant industry education, is beginning to take effect. It may also reflect that waterproofing problems can occur after the building occupants have moved in, explaining why strata managers reported a higher incidence of defects.

Gary says the regulatory focus on waterproofing has led the whole industry to take it more seriously. “Our advice is to get our input as early as possible. Understand what the product will and won't do and weigh up the cost. What service life and warranty are you looking for?" Gary explains. “There has been a reliance on product alone to do the heavy lifting. But design, good building practices and application are equally critical.”

Education is the key across ANZ

Colin Picton is our Product Segment Specialist for Waterproofing & Sealants in Australia and New Zealand. He says Fosroc ANZ can help industry customers meet their regulatory requirements and avoid costly problems down the line.

"We will help designers identify potential problems and what adjustments might need to be made to achieve the best outcome,” Colin says.

As well as detailed specifications, Fosroc ANZ offers Continuing Professional Development (CPD) training for engineers, architects and applicators, including waterproofing seminars.

“Preventing waterproofing defects starts with education. It’s important that everyone is in the loop on best practice. Building designers are like doctors – they have to keep themselves up to date on new products and technologies," Colin explains.

Independent testing for quality assurance

To give the construction industry total confidence in our products, Fosroc ANZ has embarked on a major program of independent testing.

"As part of the DuluxGroup, Fosroc ANZ will not state that our products comply with a particular standard unless we have independent testing," explains Colin. "Other products might say the material complies with a certain standard. But is the manufacturer relying on its own internal data? We believe the market can have more confidence in external independent testing.”

Of particular interest for waterproofing specifiers, our Fosroc Nitoproof liquid waterproofing membranes meet internal and external waterproofing standards, with testing complete for AS/NZS 4858 Wet Area Membranes and underway for AS 4654.1 External Above-ground Membranes. Nitoproof membranes can also be combined with Nitoproof Top Coat UV and Nitoproof Top Coat EW to achieve AS 4586 Slip Resistance.

Find out more

Request a waterproofing specification or CPD training with Fosroc ANZ.

Read the research on serious building defects in NSW strata communities.

Download our Fosroc Test Certificates flyer