D emand for wood-plastic composite (WPC) and plastic decks is expanding in the North American market at a double-digit rate.
Demand for wood-plastic composite (WPC) and plastic decks is expanding in the North American market at a double-digit rate.
Despite this, the market penetration, acceptance and growth of these products for new residential construction is being hampered in Canada by the absence of published performance/ product standards. While not a problem for small do-it-yourself construction projects, this lack of certification can pose a serious impediment to projects requiring a building code permit.
“The use of WPCs and plastic lumber would be unquestioned if these products conformed to a published standard referenced in the National Building Code of Canada and the Provincial Building Codes,” said Guy Titley, P. Eng., a consultant with the Canadian Plastics Industry Association (CPIA). “Such a standard would outline minimum product and performance properties for these products to meet structural, safety, durability and quality requirements.”
A QUESTION OF STANDARDS
Absent a set of Canadian standards addressing these products, their acceptance for use in building code permit construction has generally fallen to the CCMC (Canadian Construction Materials Centre), a part of the Division of Building Research of the National Research Council of Canada. The CCMC’s mandate is not to produce standards, Titley said, but to evaluate the suitability for use in Canadian construction of materials for which no Canadian product/ performance standards exist.
For these reasons, the CCMC evaluates each individual product separately and publishes an evaluation report stating acceptability of a given WPC product. “Unfortunately, individual evaluations by CCMC do not necessarily require the same performance level or testing requirements for all products,” Titley explained. “This is the disadvantage of having individual evaluations compared to conformance to a common set of performance limits in a published standard.”
The CCMC method of evaluation uses generally accepted physical property and performance testing methods, such as those employed by the American Society for Testing and Materials and ISO, for determining individual products.
At present, all Canadian WPC and plastic decking and guardrail system manufacturers must obtain a CCMC evaluation report to be used in new residential construction. “Unfortunately, this process can take as long as four years and over $100,000 to complete for a single product,” Titley said.
SEEKING A MANDATE
Adding to the difficulties, the CCMC does not have a mandate to produce standards for these products, with the result that it has been left to manufacturers and manufacturing associations to drive the process forward.
According to Titley, the CNCC (Canadian Natural Composites Council) of the CPIA has been active in this regard, forming a Standard Development Task Group two years ago with the goal of having a Canadian standard developed, published and eventually referenced in the National Building Code of Canada. “Such a standard would ensure a common set of product and performance properties appropriate for Canadian construction and reduce the use of substandard products in the marketplace,” he explained. The Task Group is composed of consultants and 11 product manufacturers, Titley continued, and hopes to charge a Canadian SDO (Standard Development Organization) with the task of creating this standard.
To date, only three composite decking manufacturers — Brite Manufacturing Inc. of Bolton, Ont.; Millenium Decking of Nisku, Alta.; and Trex Company Inc., of Winchester, Va. — have attained certification for their products in Canada. For projects going ahead without certification, an engineer must certify the construction blueprint.
U. S. GETS IT RIGHT
The situation in Canada compares unfavourably to the U. S., which insiders say has done a good job of achieving consistency in WPC regulations.
For example, American manufacturers can easily access a list of the tests necessary for certification through agencies like ICC Evaluation Services Inc. ICC evaluates product suitability based on product and performance requirements published in an established, single set of performance requirements called Acceptance Criteria. “This Acceptance Criteria document performs the same role as CCMC Technical Guides but, unlike the CCMC guides, applies universally to all products of that category and intended use,” Titley explained. “This greatly reduces the time and costs needed to bring theinnovative product to market.”