Concrete Cancer​

Concrete cancer can destroy properties and be a significant safety risk if action isn't taken to treat or prevent it

Concrete cancer is the gradual destruction of concrete caused by water penetration and can lead to a building's structural integrity being compromised and the safety of its occupants. When water penetrates concrete through fine cracks or weathered, porous surfaces, it rusts the structural steel within which then expands creating more concrete cracks, water penetration, cancer spread and spalling (when concrete starts to fall off a building).

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Danger signs your property might have or be susceptible to concrete cancer 

  • fractured concrete: when steel reinforcement rusts it expands causing the surrounding concrete to crack.

  • rust stains: when water penetrates steel reinforcement in concrete it begins to rust. 

  • drummy concrete surfaces: concrete surfaces that sound hollow when tapped with a hammer usually mean concrete cancer is present.

  • rusted balustrade fixings: over time rust from fixings will spread to the embedded concrete and structural steel.​

  • worn concrete surfaces: porous surfaces often with fine cracks allow water absorption and the concrete cancer process to start.

  • failing control and expansion joints: if the joints do not offer the correct allowance for concrete movement (thermal expansion and contraction) it can lead to concrete fracturing, water penetration and concrete cancer.

  • inadequate concrete cover: if the steel reinforcement is too close to the surface any water that permeates can easily access the steel causing it to rust.

  • moisture staining and ponding: inadequate water drainage ie when drainage outlets or ‘pops’  are too narrow water is able to ‘pond’ and soak into the concrete leading to concrete cancer.​

Solutions to concrete cancer

Treating concrete cancer correctly requires complete concrete breakout to remove the rust from all surfaces of the steel, and reinstate the concrete using specifically engineered structural patching materials.

Once repairs are carried out, and robust, flexible, non-slip waterproof coatings applied, the repairs and original surfaces are given added protection from the development of new concrete cancer.

Conspar work methodology is verified and recommended by structural engineers. 


951 Beaufort St , INGLEWOOD 6052