Bamboo flooring has exceeded all industry expectations of market share, and it is considered that the popularity of this product is due to a combination of factors including the ‘green image’, durability and of course fashion trends. The rise in popularity of bamboo flooring also forced learning’s on the physical differences between bamboo and traditional timber flooring, which through the early years resulted in many failures across Australia and New Zealand. As the failures were investigated and analysed, common physical factors emerged which indicated that bamboo was different to timber and required a different installation strategy.
Two important factors evolved regarding bamboo, which required a different understanding to that of timber. It was established that the in-service moisture content of bamboo was lower than timber, and that the vapour transmission rate through bamboo was inhibited by the products extreme density. Research found that conventional epoxy vapour barriers used on concrete slabs were ineffective when used with bamboo flooring since the rate of transmission through the barriers exceeded what could pass through the bamboo. This resulted in a sub-floor build-up of moisture leading to varying degrees of permanent distortion.
As a consequence of the vapour transmission issue, most distributors of bamboo flooring would only guarantee bamboo installations which were floated on underlay, and not glue fixed, due to the enhanced vapour protection of foil backed floating floor underlays. Whilst floating bamboo over foiled underlay did resolve the vapour transmission problem, the acoustic effects of sound resonating from normal foot traffic did not suit all consumers.
In more recent times, a new generation of polyurethane vapour barriers and polymer adhesives have evolved, with German products such as Wakol PU280 offering greatly enhanced vapour transmission protection. Extensive testing of this system has confirmed that with two applications of the vapour barrier, the rate of vapour transmission reduces to below 1 gram/m²/day representing an improvement over conventional epoxy barriers in excess of 1400%. As a consequence, glue fixed bamboo flooring using the prescribed system has been reintroduced as a warranted option by some bamboo suppliers…including Planet Timbers.