DECKING
As the WPA said three years ago , the environmental benefits of using wood are compelling and align with the concept of a circular economy . By any measure of sustainability , wood scores highly ; managed properly , trees provide a renewable material that absorbs and stores ( sequesters ) carbon . At the end of its life wood can be reused in a cascading process of uses , recycling or recovery of energy . The same cannot currently be said for many other construction materials , including the increasingly popular Wood Plastic Composite ( wpc ) decking , cladding and fencing products . Although some are recycling waste plastics in their product formulations , this plastic cannot be recycled further and only a handful of manufacturers are offering to take it back once the consumer no longer wants it . It is an issue which may become more apparent in the next 10 years or so .
Industrial timber preservative treatment plant at James Jones .
Enhancing Durability Using more wood is great – however it ’ s not as simple as it may seem . The main softwood species used for building and landscaping applications include Pine and Spruce . They are fast growing and so used more frequently because of availability and furthermore , affordability . However , softwoods are generally not as durable as slow growing more expensive hardwoods . The good news is that the durability of softwood products can be enhanced using preservative treatments or wood modification processes to protect against fungal decay and insects during its service life . This in turn , reduces pressure on the more naturally durable , scarcer and higher value species . Pre-treatment allows the use of the more perishable ( sapwood ) and nondurable parts of a tree where they might otherwise be discarded or have a short service life . This makes the most of the timber resource and contributes to waste minimisation .
Developing Technologies The additional energy input of pre-treated wood production is comparatively low too – there is an increasing amount of research driven evidence to support this . But what about the ‘ chemical ’ aspect of treatment ? The treatment industry is highly regulated and continues to develop products and processes which are better targeted towards the organisms we wish to control and which have less impact on the wider environment . This trend will continue . By assessing the benefits gained , then the justification for timber treatments can be appreciated .
Fit for purpose Like any other materials , treated wood must be correctly specified and installed to ensure its performance meets service expectations . It ’ s a mistake to assume that all pressure treated wood is the same . Whilst one piece of treated wood may look like any other , the level of preservative protection could be very different . British Standards require that the treatment process is tailored to the end use . Wood for outdoor applications needs higher levels of protection than wood products used indoors . Nowhere is the fitness for purpose of treated wood more important than for landscaping timber which is in direct contact with the ground or providing exterior structural support . This falls into the ‘ Use Class 4 ’ treatment standard . So when specifying or buying such treated landscaping timbers , first and foremost , make sure the supplier knows the timber is for a Use Class 4 application ; secondly make sure the wood is treated by a process certificated under an independent quality scheme such as WPA Benchmark ; and finally , remember that high performance materials do cost more .
Learn more about timber treatments and the work of the WPA here : www . thewpa . org . uk
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