Buying a property in Sydney is a significant investment. From stunning harbourside apartments to classic Federation homes, the dream of owning a piece of this vibrant city is strong. However, for those eyeing older apartments built between the 1920s and 1980s, a hidden threat lurks beneath the surface: magnesite flooring. This common, yet often misunderstood, material can lead to costly structural damage known as "concrete cancer." In this article, we’ll break down what magnesite flooring is, why it's a critical inspection point for Sydney buyers, and what steps you can take to protect your investment. What Is Magnesite Flooring and Why Is It a Risk? Magnesite flooring, also known as magnesium oxychloride cement, was a popular levelling compound used in older apartment blocks across Australia. It was praised for its soundproofing and fire-resistant properties. However, its major flaw lies in its high chloride content. When magnesite is exposed to moisture—from a leaking balcony, a faulty shower, or even just high humidity—it releases these chlorides. These chlorides can then seep into the concrete slab below and corrode the steel reinforcement bars. This corrosion causes the steel to expand, which in turn cracks the surrounding concrete. This destructive process is commonly referred to as concrete cancer. For more insights, our friends at @ElymentGroup have published an excellent resource on this topic at elyment.com.au. They highlight how crucial it is to address this issue early to avoid a major financial headache. The Tell-Tale Signs You Need to Look For As a prospective buyer, you can't see the corrosion happening inside the concrete, but you can spot its effects. Here are some key indicators that may point to magnesite-related problems: Yellow or brown staining: Often visible on the flooring or at the edges of a concrete slab. Cracking or bubbling: The magnesite layer may show signs of cracking, lifting, or bubbling. Uneven or damp floors: Floors that feel uneven or are consistently damp, especially in kitchens, bathrooms, and laundries. White, powdery deposits (efflorescence): These are salts migrating to the surface of the concrete. Why a Standard Building Inspection Might Not Be Enough Many standard pre-purchase building and pest inspections in New South Wales have disclaimers that exclude the detection of magnesite flooring or concrete cancer. It’s crucial to understand that without a specialist’s eye, this problem can be completely missed. A specialist inspection, often conducted by a structural engineer, involves non-destructive testing and chemical analysis to determine the presence of chlorides and the extent of any damage to the concrete slab. This is a small price to pay to avoid a potentially massive rectification bill down the line. Key Takeaways for Sydney Home Buyers Don't risk it. If you’re considering an older apartment, a magnesite inspection is a non-negotiable part of your due diligence. Know the signs. Be on the lookout for visible signs of damage like cracking, staining, or uneven floors. Get a specialist. Relying on a standard inspection could leave you exposed. Engage a qualified structural engineer who can test for and identify the problem before you sign on the dotted line. Protect your investment and your peace of mind. Get expert advice on structural integrity and magnesite flooring from the specialists. Run Your AI-Powered Magnesite Risk Check Now!