b'Climate Resilience CSA A123.26 Features and BenefitsAn IIBEC Members PerspectiveBy Doug Fishburn, GRP Fishburn Building Sciences Group Inc. Hornby, Ontario, CanadaFeatures and Benefits for Building Owners Figure 5a: Normal probability distribution of load, resistance and installation.Providecleardirectiontothebuildingdesigneroftheownersexpectationsforthe roof performance.Provide assurance that the roofs have been designed to meet or exceed the national building code requirements.Provide a level of known performance to the purchaser if the property ownership changes.Reduce the possibility of perspective purchasers to reduce the sale price if the design and installation of the roof is otherwise unknown.Will reduce the life cycle cost of the roof since the likelihood of a failure is reduced.Increase the roofs reliability to function during major weather events.Provide a known design standard with which to compare the roof performance should a(decreased failure zone with the incorporation of installation). Note:= reliability index. Figure 5b: The load resistance factor design approach for low-slope membrane roofing systems weather event result in wind damage, ponding overstress or roof leaks.Reduce ambiguity, which should result in more accurate bids to the owner. Figure courtesy of Reference 9.Features and Benefits for Building Designers This ensures that the design accounts for variabilities in the load, Provide clear direction from the building owner to the designer as to the owners expecta- material properties and uncertainties in the resistance determina-tions for the roof performance in order to lower the risk of contractors value engineeringtion; as a result, the overall reliability of the design is higher. It is the roof after the bids are received. assumed that the roof system installed in the field is the same as Establish a known standard for design and quality assurance from the outset. the system that was tested in the laboratory and that its resistance Provide a simplified approach to prepare specifications and drawings. is higher than the design requirement. However, the construction Provide a guide to follow when preparing specifications and drawings. process and application techniques can cause variations in the Provide a guide when reviewing shop drawings. roof system, which can lead to deficiencies and a lower resistance Reduce the risk of failure that could otherwise involve the designer in a construction claim. than that obtained in laboratory evaluations. To further increase the reliability of the roof system and decrease the risk of its failure, Features and Benefits for Contractors the obtained LRFD value must consider installation uncertainties (Figure 5b). A smaller failure zone will lead to greater reliability Provide clear direction on how the roof is to be constructed. and a larger sweet spot. 6Therefore, to attain resiliency against Eliminate ambiguity and assist the contractor in providing accurate bids. climate change, the integration and implementation of the three Provide a known standard that can be relied on for warranty purposes. criteria must be cohesively met.Provide a level of quality assurance, which is intended to reduce oversights in the contrac-tors work. CSA A123.26 Development ProcessReduce the risk of callbacks and warranty claims. The task group charged with developing CSA A123.26 oper-ated under the norms of the CSA Group, with the participation of Why Is the Standard Needed? stakeholders from across North America (see Table 1 for the list of Currently, the national building code is the only authoritative standard used in Canada.members). There were two working groups within the task group Typically, the building code does not apply to reroofing. CSA A123.26 could apply to bothfocused on the wind and rain sections.new construction and reroofing. The RCI Foundation Canada contributed to the development CSA A123.26 is a consensus standard that incorporates the current knowledge of roofingof experimental data to validate the field wind uplift protocol, and trade organizationsdesign community as well as roofing manufacturers. There is no con- several IIBEC members participated in the consensus process by sensus standard for reroofing of low-sloped roofs in Canada. This standard fills the void. contributing to content development for the standard. To gather The current recommendations of trade associations and manufacturers provide guidanceinput from peers, Gaur and co-authors presented the standards on current practices, but they do not address issues that can result in an increase in wind orframework to the roofing industry. 10The extensive collaboration rain events that are anticipated to occur from global warming. Most manufacturers warran- with diverse stakeholders was critical for identifying the best prac-ties have limitations if the wind speeds exceed a specific requirement. Manufacturers couldtices followed by the industry and ensuring the completion of the simply state that the roof must be designed and constructed in conformity to CSA A123.26.consensus-based standard. This collaboration also helped identify If they adopt this approach, it would reduce the warranty claims. strategic and practical solutions for implementation of the stan-This standard allows roofs to be designed and constructed with more predictabilitypar- dard by the construction community. The sidebar to this article, ticularly when the roof is exposed to extreme weather events. Based on my experience,CSA A123.26 Features and Benefits, highlights those solutions most roofs are found unserviced due to construction oversights. This standard is intendedfrom the perspective of users of CSA A123.26.to address this problem.How the Standard Could ApplyThe standard could be referenced by owners, designers, manufacturers, roofing trade or-ganizations or contractors as to the quality of roofing intended to be achieved. The user guide, when developed, could be used as a reference guide by the entire roofing commu-nity as to how to design and construct a roof that has proven performance or benefits over current standards.The standard is adaptable for most roof membrane systems currently used in Canada and is applicable for both small and large projects, whether they apply to new or reroof-ing projects.What Is the Advantage of Applying the Standard?Roofs designed to this standard are more reliable and should last longer, with fewer main- Figure 6: The layout of standard CSA A123.26 Performance Requirements for Climate Resilience of tenance problems and roof leaks. Low Slope Membrane Roofing Systems. Note: numerals in ovals signify the number of require-ments for Gold in each category.20ONTARIO ROOFING NEWSISSUE 4 2021/22 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'