b'TECHNOLOGYThe new wind uplift rulesBy/par Jean-Franois Ct, Ph.D., SopremaNouvelles rgles de rsistance au ventI n its 2015 edition, the National Building Code of CanadaD ans son dition de 2015, le Code national du bti-(NBCC) inserted for the first time a reference to the CSAmentduCanada(CNBC)inclutpourlapremire A123.21 standard as a means to determine the wind upliftfois une rfrencela norme CSA A123.21 comme resistance of a low-slope roofing assembly. Previous editionsmoyen de dterminer la rsistance au soulvement par le of NBCC required the calculation of wind loads acting on avent dune toiturefaible pente. Les ditions prcdentes building, but provided no guidance on how to select a roofingdu CNBC exigeaient le calcul des charges, mais ne fournis-assembly that would resist these loads. saient aucune orientation sur la faon de choisir un ensemble Since the publication of NBCC 2015, our industry wentde couverture.through a transition period during which guidelines of theDepuis la publication du CNBC 2015, notre industrie a new model code started to be implemented selectively andconnu une transition au cours de laquelle les lignes direc-voluntarily prior to their formal adoption by authorities havingtrices du nouveau code ont commenctre mises en jurisdiction. Gradually, each party became more familiar withuvre de faon slective et volontaire avant leur adoption its respective role and the expectations from other stakeholders. officielle. Peupeu, chaque partie sest familiarise avec son rle respectif et les attentes des autres intervenants.Designers roleFor each individual building intended to be covered with aRle du concepteurlow-slope roofing assembly, NBCC Article 5.2.2.2 requires thePour chaque btiment devant tre recouvert dune toituredesigner of record to determine the wind loads acting on thefaible pente, larticle 5.2.2.2 du CNBC exige que le concep-building in accordance with Subsection 4.1.7. The wind loadsteurdtermineleschargesdeventconformmentla are specific to this building and are based on parameters suchsous-section 4.1.7. Les charges sont propresce btiment as building shape, dimensions, occupancy, surroundings andet sont bases sur des paramtres tels que la forme, les geographical location. dimensions, loccupation, lenvironnement et lemplacement.42 ROOFING CANADA FALL/WINTER 2019'