ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWS – ISSUE 1 2026 15 sible if the roof was not reason- ably maintained and substantial amounts of wet components were identified. Key engineering concerns are carefully managed through- out the design process. Air and vapour barrier discontinuities at penetrations, perimeters and expansion joints are addressed through localized roof replace- ment to tie in a new air and va- pour barrier. In Canada, roof systems that consist of new roof- ing components must be tested to CSA 123.211 for uplift resis- tance; however, roof re-cover systems incorporate both old and new roof components with an assembly composition that may not match pretested sys- tems. Engineering judgement, by a qualified engineer, may be required to determine appropri- ate mechanical fastener and ad- hesive spacing for wind uplift. As part of the design, existing roofing components are all me- chanically fastened so as to not rely on the existing securement system that may be compro- mised while removing the exist- ing membrane. Fastener lengths and underdeck conduit map- ping are specified to avoid con- tact with conduits beneath steel decks – a critical consideration in active industrial environ- ments. Test openings are created at thermal anomaly locations to measure moisture content (>5 per cent) for future replacement (Fig. 2) and to also review the underlying steel decks for re- pairs, as necessary. The environmental benefits of roof re-covering are quanti- fiable. To assist with embodied carbon calculations, an Excel- based calculator was created with available manufacturer- specific environmental product declarations (EPDs). At one of our past roof re-cover proj- ects, a building with 74,322 m2 (800,000 ft2) of roof area achieved an estimated 310 tonnes (~342 tons) of carbon dioxide-equivalent (CO2 eq.) savings and diverted approxi- mately 400 tonnes (441 tons) PlastiSpan ® Insulation • The right price • The right schedule • The right customized tapered insulation • The right decision Helping Create Lasting Communities™ www.plastifab.com What makes this approach both technically robust and replicable is its reliance on conventional materials and assemblies, which ensures contractor familiarity, competitive bidding and long-term membrane performance. of material from landfills, based on an assumed 60-year study period. We completed a total of approximately 195,096 m2 (2.1 million ft2) of roof re-cover proj- ects to date, with each project executed under this enhanced roof re-cover model demonstrat- ing embodied carbon reductions of 28 per cent or more compared to full replacements. Based on extrapolation, we estimate that our roof re-cover projects have saved over 1,800 tonnes (~1,984 tons) of CO2 eq. emissions and diverted nearly 2,000 tonnes (2,205 tons) of waste. Case Study: Quantifying Impact on a Large Industrial Warehouse To further validate and refine these principles, we undertook a comprehensive embodied car- bon study for a significant proj- ect: a large, one-storey industrial warehouse facility with an ap- proximate roof area of 99,964 m2 (1,076,000 ft2). The existing conventional built-up roof sys- tem was at the end of its service life. The cradle-to-grave embod- ied carbon assessment aligned with the National Research Council Canada’s National Whole-Building Life Cycle As- sessment Practitioner’s Guide2 and primarily leveraged product- specific EPDs. The study evalu- ated three distinct roofing res- toration scenarios over a 60-year study period: Scenario 1 (Roof Replace- ment [Baseline]): This repre- sented a typical full-roof-system replacement with a new two-ply modified bitumen system, in- cluding new insulation and an air and vapour barrier. This sce- nario assumed two additional full replacements over the 60- year study period. Scenario 2 (Roof Re-Cov- er/Renewal): This involved re- moving only the existing multi- ply membrane while retaining the existing overlay fiberboard, insulation and vapour retarder. The existing membrane is to be removed and replaced with a two-ply modified bitumen
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