Magnesite flooring was widely installed in high‑rise apartments from the 1960s to the early 2000s. Today, it is one of the most significant hidden risks inside Australian strata buildings. As magnesite breaks down, it releases moisture and chlorides that attack the concrete slab beneath—causing reinforcement corrosion, concrete cancer, and long‑term structural defects.
For strata committees, building managers, and owners, understanding and addressing magnesite decay is critical to avoiding costly slab repairs and compliance risks.
CPR specialises in diagnosing, removing, and remediating magnesite‑affected slabs in difficult‑access and high‑density buildings, ensuring long‑term structural protection using our Scaffold‑Free™ systems and engineered repair methodologies.
Magnesite flooring was originally used as a topping compound to level concrete slabs. Over time, exposure to moisture causes magnesite to break down into salts. These salts penetrate the concrete, accelerating deterioration.
Common magnesite flooring problems include:
These magnesite flooring issues remain one of the most common internal defects found during strata inspections across NSW.
While combustible cladding often receives media attention, magnesite can be a far greater long‑term structural threat. Why?
If left untreated, magnesite decay can trigger extensive concrete slab corrosion, structural instability, and multi‑million‑dollar remediation works.
This makes it one of the leading contributors to high‑rise building defects and long‑term liabilities for strata schemes.
As magnesite absorbs moisture, it forms chlorides that attack the reinforcing steel inside the slab. This results in:
These issues often remain hidden under carpet or flooring until serious deterioration occurs.
If your apartment building was constructed between the 1960s and early 2000s, there is a high chance magnesite flooring was installed. Early detection prevents structural deterioration and reduces future repair costs.
Explore our full suite of facade remediation and preservation services or learn more about our engineered concrete durability repair treatments
