Sydney’s iconic apartment buildings, especially those constructed between the 1920s and 1980s, are hiding a silent threat: concrete cancer caused by magnesite flooring. This seemingly innocuous material, once a popular choice for floor levelling and soundproofing, is now wreaking havoc on homes across the city. If you own or live in an older strata property, understanding this issue could save you thousands in repairs and protect your home’s structural integrity. In this article, we’ll uncover what magnesite flooring is, how it triggers concrete cancer, and what you can do to safeguard your property. Visit us at elyment.com.au for expert solutions to this growing problem. What is Magnesite Flooring? Magnesite flooring, made from magnesium oxychloride mixed with fillers like sawdust or wood chips, was widely used in Sydney’s residential and commercial buildings from the 1920s to the 1980s. Its appeal? It was durable, fire-resistant, and excellent for soundproofing, making it a go-to choice for levelling concrete slabs in multi-storey apartments. However, magnesite has a dark side. This material is highly porous and absorbs moisture like a sponge. When exposed to water—whether from leaks, poor waterproofing, or even humid coastal air—it triggers a chemical reaction that releases harmful chlorides. These chlorides seep into the concrete slab below, corroding the steel reinforcement and setting the stage for concrete cancer. Understanding Concrete Cancer Concrete cancer, also known as concrete spalling, occurs when the steel reinforcement within a concrete slab corrodes. As the steel rusts, it expands up to seven times its original volume, causing the surrounding concrete to crack, flake, or “spall.” This not only weakens the structural integrity of your home but can also lead to costly repairs or, in extreme cases, building collapse. Common Signs of Concrete Cancer Cracked or bubbling floor tiles: Tiles may lift or crack due to pressure from expanding steel. Lumps under carpets: Rusting steel causes the concrete to bulge, creating uneven surfaces. Rust stains or exposed rebar: Visible rust or steel protruding from the concrete is a red flag. Powdery or chalky floors: Magnesite deterioration can leave a dusty residue. Moisture or damp odours: Persistent dampness in areas like bathrooms, kitchens, or balconies. If you notice any of these signs in your Sydney property, it’s time to act fast. Why Magnesite Flooring is a Problem in Sydney Sydney’s older buildings, particularly in coastal areas like the Eastern Suburbs and Northern Beaches, are especially vulnerable. The city’s humid climate and proximity to saltwater accelerate the corrosion process, as salt in the air hastens rust formation. Up to 90% of apartments built between 1961 and 1979 may contain magnesite flooring, affecting over 186,000 units across New South Wales. Magnesite flooring was typically laid as a common property element, meaning strata committees are often responsible for its removal and repairs. However, changes in strata by-laws can shift costs to individual owners, so it’s crucial to check your building’s regulations. The Hidden Dangers of Asbestos To make matters worse, some magnesite flooring contains asbestos, a hazardous material linked to serious health risks like lung cancer and mesothelioma. If your flooring was installed before 1987, it’s wise to have it tested by professionals before any removal work begins. Attempting to remove magnesite yourself could release harmful asbestos fibres into the air. How to Address Magnesite Flooring and Concrete Cancer The good news? Magnesite flooring issues can be managed with prompt action. Here’s how to tackle the problem effectively: Professional Inspection: Engage a remedial builder or structural engineer to assess your flooring. Tests like electrochemical assessments can measure chloride levels and corrosion extent. Magnesite Removal: Specialised contractors use dust-free methods, like shot blasting or scarifiers, to safely remove magnesite. If asbestos is present, certified abatement professionals must be involved. Concrete Grinding and Repairs: After removal, the concrete slab is ground to remove residue and inspected for damage. Corroded steel may need cleaning, and sacrificial anodes or cathodic protection systems can prevent further corrosion. Floor Levelling and Reinstallation: A new, modern levelling compound, like Ardite, is applied to prepare the slab for new flooring. This ensures a smooth, durable surface. Ongoing Maintenance: Regular waterproofing and sealing in moisture-prone areas (bathrooms, balconies, kitchens) can prevent future issues. Costs for magnesite removal typically start at $42 per square metre, with additional expenses for concrete grinding ($40–$65 per square metre) and waste disposal ($150–$750). For severe concrete cancer repairs, costs can range from $5,000 to over $250,000, depending on the damage. Why Act Now? Ignoring magnesite flooring and concrete cancer can lead to: Structural Risks: Weakened slabs may compromise your building’s safety. Rising Costs: Delaying repairs increases damage and expenses. Health Hazards: Asbestos exposure poses serious risks if disturbed. Failed Flooring Systems: New flooring installed over magnesite is likely to fail, voiding warranties. Strata committees may cover removal costs if magnesite is deemed common property, but don’t wait for approval to investigate. Early detection can save you from special levies or unexpected bills. Key Takeaways Magnesite flooring, common in Sydney’s older buildings, absorbs moisture and releases chlorides, causing concrete cancer. Concrete cancer weakens structures through steel corrosion, leading to cracks, spalling, and costly repairs. Signs to watch for include cracked tiles, bulging floors, rust stains, and damp odours. Professional removal is essential, especially if asbestos is present, to ensure safety and compliance. Act promptly to avoid escalating repair costs and structural risks. For expert magnesite removal and concrete repairs, contact Elyment Group or follow us on X at @ElymentGroup. Protect Your Sydney Home Today Don’t let magnesite flooring silently destroy your home. If you suspect concrete cancer or live in a building constructed before the 1980s, schedule a professional inspection now. At Elyment Group, our experienced team specialises in safe magnesite removal, concrete repairs, and floor levelling to restore your property’s safety and value. .cta-btn { background-color: #022b5f; /* Elyment Group blue */ color: #ffffff; border: none; padding: 14px 32px; border-radius: 30px; /* Softer, modern pill look */ cursor: pointer; text-align: center; display: inline-block; margin-top: 20px; font-family: 'Arial', sans-serif; font-size: 15.5px; font-weight: bold; letter-spacing: 0.5px; text-transform: uppercase; transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease; box-shadow: 0 4px 12px rgba(2, 43, 95, 0.4); text-decoration: none; } .cta-btn:hover { background-color: #16443e; box-shadow: 0 6px 18px rgba(22, 70, 138, 0.6); transform: scale(1.05); } Safeguard Your Home Now !function(e,t,n,s,u,a){e.twq||(s=e.twq=function(){s.exe?s.exe.apply(s,arguments):s.queue.push(arguments); },s.version='1.1',s.queue=[],u=t.createElement(n),u.async=!0,u.src='https://static.ads-twitter.com/uwt.js', a=t.getElementsByTagName(n)[0],a.parentNode.insertBefore(u,a))}(window,document,'script'); twq('config','pbp7d');