Viewpoint - Addressing the drywall dilemma
It is estimated that the construction industry consumes approximately 40% of the global material flow, and generates about 33% of the North American solid waste stream. Of the Construction & Demolition [C&D] waste, 15% is comprised of gypsum drywall product. If we want to change these numbers we need to start viewing materials found in the waste stream as resources or commodities rather than as waste.BY RENÉE GRATTON
Our current state
Gypsum is a relatively inexpensive mineral long mined throughout the world, becoming a commodity product in the form of gypsum wallboard for the building industry over the last 60 years. Although the drywall industry has made some environmental progress, reports show that extraction of this non-renewable mineral will continue to climb at a rate of 2% annually through 2013, continuing environmental degradation.
While drywall board is a safe product, composed of 0.5% by weight of starch which is rapidly biodegradable, it produces the toxic hydrogen sulphide gas when mixed with organic waste and exposed to rain in an anaerobic environment such as landfill, sewer or wetland mud.
Recycling construction waste is one of the most visible commitments a developer or builder can make to sustainability. Used gypsum board can and is being recycled into new gypsum board, however, Canada’s drywall recycling infrastructure lags far behind that of the US and Europe. While New West Gypsum Recycling has been operating for many years in Langley, BC and in Oakville, ON, and Recycle Gypse Québec for three years in St-Rémi, Quebec, still few municipalities have banned drywall waste from landfills. This, along with inconsistent standards, regulations, infrastructure and services, contributes to Canada’s poor performance in waste management.
Sadly, in view of these factors, there has been little to no business case for new drywall recycling. However, there are some bright spots. BC has led by example with its strong regulations on drywall recycling introduced several years ago. And as cost is still perceived to be prohibitive, owners and consultants are now starting to truly grasp real costs as negligible for any environmentally conscious developer or consultant.
Last but not least, the Canadian Standards Association’s work on its Guidelines for Deconstruction is involving a variety of design and building professionals, and manufacturers, and will recommend ways to re-use building products and divert waste from landfills. As well, important research is happening now for the use of gypsum waste in other applications such as compost, and as additives in other products etc. There is finally a reasonable expectation for increased market interest and competitive pricing to encourage recycling.
How to bring change
As we all try and focus on reducing our carbon footprint, we must remember that for every ounce of material that is not recycled and as demand for new board grows, new non-renewable raw gypsum is extracted, and associated embodied energy or other negative environmental impacts also continue to grow.
Basic strategies to catalyze change in the industry
Minimization of material use
Green building design strives to reduce the use of materials such as gypsum board by considering minimizing interior walls for a more open concept design; leaving structural elements such as concrete walls or columns exposed; planning interior space based on the most efficient board dimensions; and modular design using mobile or demountable partitions, etc.
Designers can also consider Life Cycle Analysis [LCA], a technique for compiling and evaluating the inputs and outputs and the potential environmental impacts of a product system throughout its life cycle. While this is complex and likely difficult to undertake by designers, LCA practitioners use a number of standards to quantify and compare building materials and systems, and can provide options based on environmental impacts.
Alternatively, software and other tools such as those provided by The Athena Institute [www.athenasmi.ca] are available to assist designers in understanding the impacts of various materials.
Specifications and Recycling
Specifications section 01 74 21 - Cons-truction/Demolition Waste Management should be reviewed and edited as required to specifically address all recyclable materials, including drywall, as well as note local regulations. Specifications on new drywall should also be revised to include high recycled content. Recycling into soil, compost or bio-solids should be supported by professionals, standards and guidelines.
Wherever possible, design professionals and their governing bodies should advocate at all levels of government for the introduction of legislation that would support the establishment of a nationwide network of drywall recycling facilities, to bring this most ubiquitous of construction materials into a closed loop of recycling and reuse.
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