After comparing wood, brick, and concrete construction for residential buildings Kuzman et al. stated that “In the light of the growing importance of energy-efficient building methods, it could be said that wood construction would play an increasingly important role in the future”.
Recycled Plastics
Outside of the construction industry the main opposition to timber is recycled plastic composites. There are currently several variations of plastic composites being used to replace wood, including recycled plastic formed into timber like beams, and glass reinforced panels (Haghdan & Smith, 2015). The rail industry has been a key driver of research into this area, with Japan starting in the 1970's and an active trial of replacing railway sleepers with plastic lumber being conducted since 1984 (Koller, 2015). Initial tests show limited degradation over a 30 year period with an estimated effective lifetime of at least 60 years (Koller). European countries have since begun to implement test sections of plastic lumber, including several road and pedestrian bridges made completely from recycled plastic. Other uses including fencing and furniture, with Australia having several schools outfitted with benches and walls making use of the material (Bajrachrya et al., 2014).
The benefits of recycled plastic are many and varied. It has a long lifecycle, can limit the amount of plastics sitting in landfills, resistance to rot and insect/animal attack, low cost, lightweight, easily manipulated, and specifically can be used in marine settings as it doesn't contain treatment chemicals such as chromated copper - common in timber used in marine applications - that can leak into the sea (Bajracharya et al.).
Aternatives to Timber
Author: Gene Hopkins
Construction
Taking a look at the construction industry in particular raises some concerns for the future of timber production.
There are currently three main building materials used for construction; timber, steel, and concrete (Kuzman et al., 2013). With an increased demand for speed and economy, pre-fabricated steel structures are becoming more common as they can be unloaded off a truck and quickly erected, drastically minimizing labour costs. Steel framing is also light and strong, with the ability to withstand high stress before distorting.
Concrete based products, in particular 3D Sandwich Panels (3DSP), are also becoming more prevalent in construction across both domestic and industrial sectors. 3DSP has an excellent heat handling in comparison to timber, and is cheaper, lighter, and deals with seismic activity better than traditional wooden structures (Naji et al., 2014).
Timber falls short of the alternatives in many aspects, and looking to the future it is plausible that steel, concrete, and other technologies that have not been discovered yet will completely replace timber in construction. However in the medium term it is likely for timber to remain in use as one of the major materials used in construction due to the internationally acceptance of it as the industry standard.
The current limitations are the process needed to create the composites, and UV degradation. To effectively recycle plastic into useable lumber equivalents the mixture has to be very specific and very pure. A presence of the wrong kind of plastic renders the composite useless as the material properties change drastically. And for outdoor use the inability to handle prolonged UV exposure causes issues. This can be rectified with the addition of a synthetic stabiliser however.
Alternatives to timber are already in use but are not yet dominating the industry and will not for some time yet, especially during a time where the global community is very environmentally focused. However in the long term it is likely that plastic composite materials will come to replace timber as the industry standard in construction and other areas. As technology continues to advance it is expected that composite materials will become cheaper, lighter, and stronger, while the price to produce, harvest, and transport timber will only continue to climb. It might not be for some time yet, but timber will likely be almost completely replaced in the future.