is part of the Informa Markets Division of Informa PLC
This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.
April 16, 2019 9:00 AM - 10:00 AM
Credits: 1 OAQ Credit; 1 BOMI CPD Point, 1 RCI CEH
Now that CSA A123.21 is referenced in the National Building Code of Canada, what has changed? NBCC provides means of calculating the loads acting on the roof assembly due to wind uplift. Selection of roof assemblies suitable for use on any given building has been simplified with the development of the CSA standard. It is now possible to identify which roof assemblies have sufficient resistance to wind uplift so the code requirement can be satisfied. The challenge that lies ahead in our industry is now to make this a habit and to ensure that the right individual does the right action. Designers are expected to perform the calculations leading to the determination of the required wind loads and include this information in their specifications. On the other hand, bidders are expected to look for published test reports showing roof assemblies that offer greater resistance than calculated loads. These test reports exist because manufacturers tested their roof assemblies to the CSA standard. And as we thought we had it all figured out, NBCC moves to ultimate limit states design, imposing a 40% increase to calculated wind loads... What is the impact of this modification to the roof assembly selection process? Are safety factors still required?
Learning objectives:
Quels changements avons-nous vu depuis que la norme CSA A123.21 est apparue dans l’édition 2015 du Code national du bâtiment du Canada? Le CNB permet de définir les charges relatives à l’arrachement au vent des assemblages de toiture. Grâce à la norme CSA, il est maintenant possible de déterminer le niveau de résistance à l’arrachement au vent des assemblages de toiture. Cela simplifie grandement la sélection des assemblages appropriés pour tout bâtiment et le respect des exigences du CNB. Le défi auquel notre industrie fait maintenant face est de créer une habitude à partir de ce processus et que chaque intervenant contribue de la bonne façon. On s’attend des concepteurs qu’ils effectuent les calculs permettant de définir les charges d’arrachement au vent spécifiques à chaque bâtiment et les inscrivent dans les devis. D’autre part, les entrepreneurs soumissionnaires ont la responsabilité de proposer des assemblages de toiture dont la résistance à l’arrachement au vent est supérieure aux charges inscrites au devis. Cette sélection se fait à partir des rapports d’essai provenant des fabricants qui ont préalablement soumis leurs assemblages aux essais définis dans la norme CSA. Plutôt simple, non? Mais alors que tout était en place, le CNB évolue vers les calculs de charges aux états limites ultimes, imposant une augmentation de 40% des charges de vent calculées… Quel est l’impact de ce changement sur le processus de sélection des assemblages? Les facteurs de sécurité ont-ils encore leur place?
Objectifs d’apprentissage:
Ph.D., Director, Standards and Scientific Affairs - Soprema
Jean-François Côté holds a Bachelor’s degree in Chemistry from Université de Sherbrooke and a Ph.D. in Materials Science from INRS-Université du Québec obtained in 1998. He joined Soprema in 1999 as a research chemist where he worked on the development of adhesives and sealants used in roofing and civil engineering. From 2009 to 2015, he was Director of Strategic Development for Soprema, coordinating the activities of the Canadian R&D and technical departments of the organization. In his current role, he represents Soprema on technical committees of industry associations (ARMA, PIMA, CIMAC) and is actively engaged in various North American standards development organizations (CSA, ASTM, ULC). He is a registered chemist in the province of Québec (OCQ), is chair of the CSA A123 technical committee on Bituminous Roofing Materials, and is co-chair of the ASTM D08.04 Subcommittee on “Felts, Fabrics and Bituminous Sheet Materials”.
Canadian Roofing Contractors Association
2430 Don Reid Drive, Suite 100
Ottawa ON K1H 1E1
Tel: (613) 232-6724 / (800) 461-2722
Fax: (613) 232-2893