Understanding Concrete Cancer

Check your building façade for signs of cracked or spalling concrete.

Concrete cancer is caused when the steel reinforcing within a concrete slab begins to rust. As the steel rusts, it expands and displaces the surrounding concrete; causing it to become brittle and crack which exacerbates the issue.

Signs of concrete cancer include:

  • Delaminated and cracking concrete (concrete spalling)
  • Rust stains which seem to leak out from within the concrete
  • Bubbling (also called plating) of concrete render
  • Leaks which appear in overhead concrete surfaces

A range of factors can contribute to concrete cancer

Your building may have spalling concrete for a number of reasons, including:

  • A poorly-poured substrate which has allowed moisture to seep into it through cracks and voids
  • Inadequate preparation of the reinforcing steel when the original concrete was poured.
  • The ends of the reinforcing are too close to the surface. In heavy rains, water may seep through causing lime and other chemicals in the steel to oxidise.
  • Incompatible metals being used in close proximity to each other, thus causing a reaction which allows water into the slab
  • Stress fractures from bearing weight or general wear-and-tear allow water to penetrate the concrete and react with the steel

To discuss your building and concerns about concrete spalling, concrete cracking and concrete cancer.

CONTACT US

WE’RE HERE TO HELP

Contact us for more information and to arrange a quote.

CONTACT US

WHAT YOU SAID

LATEST NEWS

Stay up to date on the latest thoughts, trends and news in building repair and maintenance

Remedial Building Services General Manager
Q&A with John Mascitelli, General Manager

17 December 2025. By Cene Jakovljevic

We sat down with one of our latest strategic hires - General Manager John Mascitelli - to learn what his thoughts on the industry are. 

Apartments showing an ageing strata landscape where deferred maintenance is the norm
The Cracks are Showing – Structural Fatigue

24 November 2025. By Chris Jakovljevic

Cost of living pressures have dominated headlines all year. Many assume this affects only lower-income earners, but the reality — at least in strata settings — is more complex.

A red brick apartment building without render
Boost Property Values with Rendering Options

2 January 2024. By Simon Austin

Naked brickwork is making a comeback. However, owners of older buildings that used less decorative and aesthetic brick options may want to consider alternatives to a brick facade and consider rendering. But do you paint it or tint it? What is better?