Enhancing the fire resistance and fungal durability of solid wood via magnesium carbonate-based mineralization method

Enhanced fire performance and durability of wood materials and products without harmful chemicals remains an important challenge. We propose a specific magnesium carbonate-based mineralization method for improving wood durability and fire resistance. During mineralization wood samples were impregnated with an aqueous solution of magnesium acetoacetate, which subsequently transforms within the wood to form various magnesium carbonate-based compounds, predominantly different hydrated and basic phases, the specific formation of which is influenced by factors such as wood anatomy and environmental conditions during post-treatment. Unlike traditional calcium carbonate, magnesium carbonates decompose at much lower temperatures, releasing both water and CO₂, which together contribute to enhanced flame protection through cooling and dilution of flammable gases. This treatment delayed ignition time by over 50% in two case studies, Norway spruce and European beech, compared to untreated controls. Additionally, such mineral-wood composites showed significantly lower mass loss when exposed to fungi, attributed to increased alkalinity compared to the untreated wood’s acidity. This dual-function mineralization approach offers an environmentally friendly alternative for improving fire and decay resistance and presents a non-hazardous biocide-free method that could replace certain conventional treatments. • Mineral-wood composite with improved fire properties and resistance to fungi. • Proposed mineralization process is environmentally-friendly. • MgCO 3 -based compounds are formed in situ, deep within the wood’s structure. • The alkaline nature of new composite most likely slows down the fungal activity. • The time to ignition is extended by more than 50% compared to the native wood.