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Concrete Cancer Sunshine Coast

CONCRETE
CANCER

What it is, how it spreads, why it can't wait — and how Suncoast Concrete Repairs fixes it properly on the Sunshine Coast.

What is it

CONCRETE CANCER EXPLAINED

Concrete cancer is when the reinforcing steel within concrete begins to oxidise (rust) and expand. This has two dangerous effects: first, it eats away at the structural reinforcement, leaving the concrete with little internal strength. Second, it expands to the point where the binding within the concrete gives way — leading to the tell-tale cracks, chips and spalling you see on the surface.

The rust works silently beneath the surface, meaning a small visible area on the surface may indicate a far greater problem underneath. By the time you can see symptoms, the damage is almost always more extensive than it appears.

WARNING: Left untreated, concrete cancer can grow at up to 5 times per year. A 10cm affected section today could be half a metre within 12 months, then 2.5 metres the year after. If left long enough, a building can become condemned.

Critically, sealing in rust is not a solution. If an inexperienced team treats the surface issues and seals in oxidising steel, the problem has not been treated and will continue to deteriorate — often faster than before because moisture is now trapped.

Concrete cancer example
Our motto: "The best solution. The smart choice." The best solution is one that is as cost effective as possible that solves the issue — not just patches the visual symptoms.
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Rate of decay

UP TO 5× GROWTH PER YEAR

As a rule of thumb, you should expect the reinforcement within concrete that has begun to oxidise to deteriorate at up to five times per year.

1cm of rust the first year would likely be 5cm the following year, then 25cm the year after, and so on. If left untreated for any length of time a small repair job can quickly become a major building project.

This is why we urge you not to delay. Every month you wait, the repair cost grows significantly.
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Concrete cancer rate of decay graph
Warning signs

DO YOU SEE ANY OF THESE?

If you notice any of the following on your building — contact a licensed specialist immediately. Don't wait.

01
Rust Spots or Staining
Brown or orange staining on concrete surfaces is a tell-tale sign that rust is leaching through from the steel reinforcement inside.
02
Spalling & Chipping
Pressure from expanding rust within the concrete forces chips and fragments to separate from the surface. Often indicates much greater damage deeper underneath.
03
Cracks in Concrete
Cracks can be a sign of spalling or may come from the original pouring and curing stage. Either way they open avenues for water to reach the reinforcement.
04
Bubbling Paint or Render
Bubbling or blistering of surface coatings indicates that expansion is occurring underneath — usually rust beginning to push through.
05
Delamination
Where the concrete splits into layers and starts to flake. Extensive delamination can indicate that the strength and stability of the concrete is compromised.
Key terms

UNDERSTANDING THE TERMINOLOGY

Concrete repair has its own language. Here's what the key terms mean.

Spalling
Where pressure from within the concrete has forced chips and fragments to separate from the surface. Often the indication of much greater issues deeper under the surface.
Delamination
Where the concrete splits into layers and may start to flake. If extensive, it can indicate that the structural strength and stability of the concrete is compromised.
Oxidisation
When reinforcement contacts water it introduces corrosive elements such as carbon dioxide or chlorides, causing disintegration of the iron and replacing it with rust which requires more volume.
Salt & Chlorides
Highly water-soluble and can rapidly oxidise iron and steel on contact. Often referred to as 'green rust', more prevalent close to the ocean — like the Sunshine Coast.
Anodes
Sacrificial anodes are placed strategically and attached to reinforcement, using electrolysis to actively counter-act and slow the rust process — extending the life of the structure.
Epoxy Injection
An effective, inexpensive solution for repairing cracked reinforced concrete — as long as the crack isn't moving and the cause has been identified.
Common questions

FREQUENTLY ASKED QUESTIONS

What is concrete cancer and how is it repaired?
Concrete cancer occurs when reinforcing steel inside concrete begins to rust and expand — cracking the concrete from within. Treatment involves exposing the affected reinforcement, removing all rust, treating the steel, installing sacrificial anodes where required, and reinstating the concrete with polymer-based repair mortar. Only a fully licensed specialist should carry out this work.
How fast does concrete cancer spread if left untreated?
As a rule of thumb, concrete cancer can grow at up to 5 times per year. A 10cm affected area today could be 50cm within 12 months. This exponential growth is why early treatment is always far cheaper than delayed repair.
How do I know if my building has concrete cancer on the Sunshine Coast?
Look for rust staining, surface spalling (chips or chunks separating), cracks in concrete, bubbling paint or render, and delamination (concrete splitting into layers). Coastal buildings on the Sunshine Coast are particularly susceptible due to salt and chloride exposure. If you notice any of these signs, contact a licensed specialist immediately.
Do you repair concrete cancer for body corporate and strata properties?
Yes. We regularly work with body corporate managers and strata committees across the Sunshine Coast, including Caloundra, Maroochydore, Noosa and Buderim. We provide detailed written proposals to assist with committee approvals and insurance documentation.
How much does concrete cancer repair cost on the Sunshine Coast?
Costs vary significantly depending on the extent of damage, accessibility, and materials required. We provide obligation-free on-site appraisals — contact us on 0423 53 99 66 to arrange a free assessment. Early treatment is always considerably cheaper than a delayed repair.
Act now

DON'T WAIT. CALL TODAY.

If you've seen any of the above warning signs — the sooner you call, the simpler and cheaper the repair. Every month matters.

Call: 0423 53 99 66 See a Case Study