Gulf Construction Online - New materials stem wood degradation

Timber & Playwood

Residential units in the UK ... featuring Accoya wood.

New materials stem wood degradation

01 May 2009

WOOD, being an all-natural material, is susceptible to many types of deterioration, including ultraviolet (UV) degradation, particularly when used outdoors.

Until recently, there hasn’t been a true wood alternative which also combats the sun’s damaging rays. Accoya wood effectively bridges this gap, says a spokesperson for the US-based Titan Wood.
“Accoya wood is a revolution in the building materials industry. For the first time, it is possible to use wood without fear of compromising environmental integrity or being required to continually paint or stain one’s structure,” she says.
While timber was traditionally used for construction, its usage in the region declined with the warm temperatures, desert breezes and sunny days taking their toll on these natural materials and resulting in early decay and endless maintenance requirements.
While the timber industry has attempted to address these problems, the solutions put forward to date have had their shortcomings. She explains: “Making use of durable hardwoods, such as Ipe and teak helps eliminate the problem of deterioration, but has resulted in the destruction of tropical rainforests worldwide. As a major source of the world’s oxygen supply, this natural resource must be protected from further damage. Another alternative for increasing the durability of timber is the application of chemicals to softwoods.
“To date, this has provided partial solutions to these shortcomings but is not without fault. Typical treatments often make use of toxins and result in a negative environmental impact. The chemicals, commonly used to increase wood durability, are harmful to living organisms and present challenges for the safe disposal of the wood at the end of its serviceable life. When treated timber is disposed of, the chemicals may leach into the ground, contaminating the water supply; or if burned, results in these chemicals being released into the atmosphere.”
Elaborating on the attributes of Accoya wood, the spokesperson says: “Based on wood acetylation – a technology 75 years in the making – Accoya wood ensures a consistent supply of durable, dimensionally-stable, sustainable, non-toxic, solid wood. Extensive tests have demonstrated that the natural beauty of Accoya wood lasts longer even under the most severe exposed conditions. Increased durability means that the use of Accoya wood is helping to conserve even sustainable wood sources.
“Accoya wood has a superior coatings performance, primarily due to two factors: outstanding dimensional stability and resistance to UV degradation.”
It is known that acetylation of wood enhances its durability and dimensional stability. With Accoya wood, swelling and shrinkage are reduced by 70 to 80 per cent and the more stable surface of Accoya wood allows coatings to adhere better, she explains.
Additionally, dimensionally-stable wood enhances the lifespan of coatings as paints and other film-forming coatings are not subjected to as severe stretch and shrink cycles. This results in a decreased maintenance frequency.
Accoya wood’s superior resistance to UV degradation improves the life of the coating by providing a sound coating substrate and allows a wider range of feasible colour options.
“For example, very light pastel-coloured stains and clear coatings can be used since Accoya wood will not darken and ruin the effect like most woods. Accoya wood’s versatility makes it ideal for use in residential, commercial and industrial structures. It can be opaque-coated in a variety of hues or, for those wishing to enjoy the natural look of wood, transparent coated.
“With its exceptional durability, outstanding dimensional stability and zero toxicity, Accoya wood is set to become the material of choice for exterior applications such as cladding, siding, and facades,” she asserts.