b'TECHNOLOGIEThe VRA wind resistance is basedlapproche LRFD (Load and Resistance1.tablir les valeurs de conception du ontheevaluationofthreeidenticalFactor Design) du CNBC 2020. Lesoulvement par le vent [P D ] et de la as-built (VRA condition immediatelyest une mthode dingnierie permettantvitesse du vent [V D ] conformment after construction) systems. The threede tenir compte de la variabilit associeau CNBC 2020.repetitions are requested to verify theaux matriaux,linstallation et autres.2.Ilestimportantdedterminerles variability of resultswhich should bePourlassemblagedetoiturevaleursdersistancedusoul-less than 15 per cent. This also neededvgtalise construite sur place (TVCP),vementparlevent[P R ]etdela tocalculatetheresistancefactor()letest telqueconstruit permetvitesse du vent [V R ] selon la norme to apply a Load and Resistance FactordvaluerlesystmesansquilsoitCSA 123.24-21.Design(LRFD)approachofNBCCncessaire dattendre la croissance de la3.Comparer la rsistance [P Ret V R ] avec 2020. is an engineering method tovgtation. Laugmentation prvue enlesvaleursnominales[P D etV D ]. accountforthevariabilityassociatedraison de la croissance de la vgtationPour assurer la conformit au code, with material, installation and others.est prise en compte par un soi-disantlesdeuxrsistancesdoiventtre Forbuilt-in-placevegetatedrooffacteur de modification de la croissancesimultanmentsuprieuresaux assembly (BVRA), the as-built testing(FMC). Reconnaissant que la densit estvaleurs nominales.permits to evaluate the system withoutun paramtre cl de la croissance de laPour illustrer le processus, considrez the necessity of waiting for vegetationvgtation, le FMC (FMC = min [[1,6 -lexemplesuivant.Unconcepteur growth.Theexpectedenhancement( x 0,5)]] est une fonction de la densitveutinstallersurunbtimentune due to vegetation growth is taken intodu systme de vgtation [gr/cm3]. Latoiturevgtaliseconstruitesur account by a so-called Growth Modifierrsistance au vent de la toiture vgtaliseplace [TVCP] avec les spcifications Factor(GMF).Understandingthat[V R ] est calcule de la faon suivante : V R suivantes :density is a key parameter for vegetation= V avxx FMC. O V avest la moyenneLieu : Toronto [htel de ville], Ontariogrowth, the GMF (GMF = min [(1.6- de lavitesse soutenuede trois systmesToit : Faible pente [moins de 7 o]( x 0.5)]) is a function of the vegetated tels que construitsvalus.Gomtrie : Hauteur = 15 m [49 pi], systemdensity(gr/cm3).TheVRAlargeur = 80 m [263 pi], longueur = windresistance(V )iscalculatedasProcessus de conformit du Code 100 m [328 pi] et aucun parapetR LeprocessusdevrificationdelaExpositionauvent:Terrainurbain follows: V R= V avxx GMF. Where V avconformit au code peut se rsumer en[conformmentlalina 4.1.7.3.5 (b) is the average of the sustained speedtrois tapes : du CNBC-2020]of three as-built systems evaluated. Code compliance process of winda,,Menzies Direct WeldTM The process to verify code compliance can be summarized in three steps:1.Establish the design valuesTPO Coated Products uplift(P D )andwindspeed(V D )PRODUCTSwww. menzies-metal.com according to NBCC 2020.2.DeterminetheresistancevaluesofInnovative l}q)o_fing So{utions3.wind uplift (P R ) and wind speed (V R )since 1978 according to the CSA 123.24-21.Compare resistance (Pand V ) with R Rthe design values (Pand V ). For D Dcodecompliance,bothresistances must be simultaneously higher than the design values.To illustrate the process, consider the following example. A designer wants to installabuilt-in-placevegetatedroof assembly (BVRA) on a building with the following specifications:Location:Toronto(CityHall),Menzies Direct Weld TPO Coating can be applied to all Ontario o metal accessory surfaces. TPO membranes can be welded Roof: Low-slope (less than 7 )Geometry: Height = 15m (49 ft),directly to the coated surface, eliminating TPO bootsWidth=80m(263ft),Length=saving time and money. 100m (328 ft), and no parapets 1.800.665.8840 AUTOMNE/HIVER 2021 COUVERTURES CANADA 33'