Proposed Change 1332

In addition, the NBC does not address polypropylene (PP) siding and insulated vinyl siding (IVS) though they have been used for more than ten years in practice. In the absence of standards, a variety of materials have been used with inconsistent applications and results.

After reviewing the standards ASTM D3679-17, “Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) Siding,” and ASTM D4477-16, “Standard Specification for Rigid (Unplasticized) Poly(Vinyl Chloride) (PVC) Soffit,” and comparing them to CAN/CGSB-41.24-95, the following was determined:

• CAN/CGSB-41.24-95
  • was withdrawn in 2012,
  • has not been updated since 1995,
  • refers to materials that are not currently available on the market, and
  • is not currently used by the industry or in practice.
• ASTM D3679-17
  • was developed through consensus,
  • reflects materials that are currently available on the market,
  • has been recognized and used by the industry and in practice, and
  • does not address soffits, necessitating the addition of a reference to ASTM D4477-16.
• Replacing CAN/CGSB-41.24-95 by ASTM D3679-17 and ASTM D4477-16 in Table 5.9.1.1.
  • will reduce the risk of unacceptable performance and the liability of professionals, as it will allow the use of materials that are available on the market and tested for performance, and
  • will lessen the workloads of contractors, manufacturers, designers, specification writers and building officials in determining Code compliance.

Furthermore, a review of ASTM D7254-17, “Standard Specification for Polypropylene (PP) Siding,” and ASTM D7793-17, “Standard Specification for Insulated Vinyl Siding,” found that these two standards offer acceptable minimum levels of performance, thus making them acceptable for reference in Table 5.9.1.1.

The four ASTM standards (ASTM D3679-17, ASTM D4477-16, ASTM D7254-17 and ASTM D7793-17) that would be added to Table 5.9.1.1 do not specifically include cold-weather testing of the materials they cover. In a review of currently available standards for these materials, none were found to include cold-weather testing. However, the currently available standards do provide other testing requirements that indicate expected performance criteria. Therefore, the Standing Committee on Environmental Separation concluded that referencing current industry standards for these materials would be better than not referencing any standards at all.

No additional costs are expected to be incurred as a result of replacing CAN/CGSB-41.24-95 by ASTM D3679-17 and ASTM D4477-16 in Table 5.9.1.1. The benefit of this replacement is that standards referenced are relevant and current, were developed through consensus, and represent today’s products.

No additional costs are expected to be incurred as a result of adding ASTM D7254-17 and ASTM D7793-17 to Table 5.9.1.1., as materials covered in the standards have been commonly used in Canada for the last 10 years.

This proposed change would simply add references to ASTM standards that are currently in use within these product categories and would provide more material options.

Compliance with the new standards can be enforced without additional resources.

Designers, specifiers, manufacturers, contractors, building owners and building officials.