Mass engineered timber (engineered wood products with improved structural integrity) has gained popularity due to lower costs and faster construction. If the wood is harvested from sustainably managed forests, then it also has a lower carbon footprint compared to steel or concrete buildings.
Current practices to protect the interior of wooden buildings from fires require fire-retardant panels (such as gypsum and magnesia boards) or the timber must be coated with paint-like fire-retardant coatings. In comparison, the new coating developed by NTU allows for the timber to remain exposed whilst providing a flame barrier when ‘activated’ by fire.
Developed by a team led by associate professor Aravind Dasari from the NTU School of Materials Science and Engineering, this transparent fireproof coating is 0.075mm thick. When heated, a series of complex chemical reactions occur, causing the coating to become a char that expands to over 30 times its original thickness and prevents the fire from combusting the wood underneath. The exact composition of the coating is remaining under wraps, but several methods can be used to apply the barrier, which is said to need a day to cure.
In a statement, Assoc Prof Dasari said: “In our coating, we used technology to lock certain compounds and interact with the resin. They will actively participate in the chemical reactions in a systematic manner when exposed to high heat, thus leading to the formation of char. This char was engineered to be extremely heat-resistant, insulating the wood underneath from the high heat.”
The NTU team is now in licensing talks with different companies, including Venturer Timberwork which is exploring the coating to protect the mass engineered timber elements in one of its projects.
Kevin Hill, Venturer’s managing director, said: “At Venturer, like other stakeholders in the mass timber construction sector, we believe more new projects will look at using this new coating technology if fire resistance can be improved. It has the potential to reduce cost and reliance on other more expensive solutions, such as using thicker timber to increase charring layers, or by encapsulating the timber with fireboards, which negates the beauty of this sustainable and productive building technology.”
According to NTU, there are only a few products on the market that provide transparency and fire retardance. Products that claim to have both properties are either very costly or unable to pass international standards required for industry use.
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