Concrete Cancer

What is concrete cancer?

Concrete cancer (also known as concrete degradation) is the process in which the steel reinforcing inside concrete starts to rust and expand, causing the concrete to fracture from displacement and crack, allowing moisture to penetrate and corrode the reinforcing further.

This can become dangerous in areas where the concrete cancer exists in walls or ceilings / roofing as the concrete may start to spall (where pieces of concrete break away from the rest) and fall onto anything underneath.

What causes it to happen?

Concrete cancer can be caused by multiple factors including:

Use of poorly treated (or possibly untreated) reinforcing steel in the concrete
Having the reinforcing steel too close to the edge of the concrete where moisture can reach it
Cracks or holes in the concrete allowing moisture to reach the steel

How to identify concrete cancer

There are many ways to identify concrete cancer, the three best indications are:

Rust spots appearing on the surface
Cracks appearing, which allows moisture ingress to the steel reinforcing
Lifting of the concrete (cracking doesn’t always occur when lifting is present)

How do we repair concrete cancer?

The first step we do to repair concrete cancer is to identify what allowed the reinforcing steel to corrode originally and address the issue as required.

Once the origins have been identified, the concrete immediately surrounding the steel (and where it has become drummy or lose) is removed before the steel is treated for corrosion with a Nitroprime Zinc Rich epoxy resin primer coat to prevent it from degrading any further.

Treatment of the steel is the most important part of the repairs as ultimately the steel corroding is the cause of the concrete lifting, cracking or spalling.

Once the steel has been treated however, the concrete is reinstated to it’s original levels by being built up in layers using RenderRock.