b'Based on SIGDERSs research, ASTM D7586, Standard Test Method for Quantification of Air Based on SIGDERSs research, ASTM D7586, Intrusion in Low-Sloped Mechanically Attached Standard ssembl eth was developed in 2011. A Roof A ies, Test M od for Quantification of Air Intrusion in Low-Sloped Mechanically Attached series of tests were carried out by the SIGDERS Roof Assemblies, was developed in 2011. A consortium to quantify air intrusion rate for a series of tests were carried out by the SIGDERS MARS. The result showed the system with a VB consortium to quantify air intrusion rate for a decreased the air intrusion volume by 50% to MARS. The result showed the system with a VB 80% depending on the bubble pressure (the decreased the air intrusion volume by 50% to pressure on the top of the insulation/cover 80% depending on the bubble pressure (the board), membrane deflection, and volume pressure on the top of the insulation/cover change, as shown in Fig. 24.board), membrane deflection, and volume change, as shown in Fig. 24.Q13: WHAT ARE THE ATTRIBUTES OF A VEGETATEDQ13: WHAT ARE THE Figure 18. Physical characteristics of the fasteners. ROOF ASSEMBLY (VRA)?ATTRI BUTES OF A VEGETATED In a VRA, a roofing system and a vegetated Figure 18. Physical characteristics of the fasteners. ROOF ASSEMBLY (VRA)?system are assembled together, as shown inIn a VRA, a roofing system and a vegetatedmanufacturer or client has to perform only the Fig. 25. A roofing assembly consists of a deck and system are assembled together, as shown inroofing or waterproofing membrane. It includesflow test as per Section 7 of CAN/CSA A123.24 to Fig. 25. A roofing assembly consists of a deck and components such as vapor barriers or retarders, roofing or waterproofing membrane. It includesobtain the flow resistance.co insunents , covers vapo ,etc rriersodular vegetated mpo ationsuch a board rba . A m or retarders, linsulati m con ver board re- tc. A modularcultivated syste on, co sists of p , e grown or pre vegetatedsy vegetation (mo f pr les, blankets,ecultivatedQ18: WHAT ARE THE TYPICAL stem consists o du e-grown or pr or mats), growth media, a root barrier, pave s, amat dr g nag h COM PONENTS OF AN ASPHALT vegetation (modules, blanket rs, or nd as),ai rowt e m system. oot barrier, y practi , andVRA is sometimes edia, a rIn industrpavers ce, aa drainage syreferred industry prac roof.Vowever,metimes SHINGLE ROOFING (ASR)?stem. In to as a greentice, aHRA is so the termregrred to asfcan be mif.leading because it can beResidential roofs utilize different mate rial fereen roo agreen roos However, the term ginter rooted di berently,adi follows:reenpref canffe misle asng because it can be interpreted different ul , d be aows: coverings such as metal, tile, and shingles.Green roof co ly as foll reference to the colorGreen eoo ofco .g.,ae a re er roof e to the colorAsphalt shingles are used on almost 90% of thr ro f(e uldb copp ferenc ).of the roof (e.g., a copper roof). Green roof is used loosely to denote roofsGreen roof ronmentally fr lyndly prod uc ofsuchof Canadian residential roofs because of with enviis used loose ie to denotero ts s Figure 19.FP PR for different deckypes. . with environmentally friendly products suchtheir affordability, ease of install ation, and Figure 19. F R for different deck t types as those made from recycled materials (e.g., as those made from recycled materials (e.g., Figure 19. FPR for different deck types. bio-based insulations). adaptability. Residential roof is composed bio-based insulations). Roofs with energy-efficient com ponents suchRoofs with energy-efficient com ponents suchof four major components: asphalt shingle, as highly reflective roofing membranes (e.g., as highly reflective roofing membranes (e.g., white single plies or MB roof with reflec tiveunderlayment, wood sheathing and insulated white single plies or MB roof with reflec tive coating).coating). attic (Fig. 27). In addition, accessories such as Based on this, a VRA is defined as intentionalvents, sealant, nails, and eave protection also Based on this, a VRA is defined as intentional placement of an engi neered vegetated systemform part of the ASR.placement of an engineered vegetated system over the roof system (Fig. 25).over the roof system (Fig. 25).Q14: HOW DOES A VRAQ19: ARE THERE ANY MISSING Q14: HOW DOES A VRA RESPOND TO WIND?RESPOND TO WIND? LINKS IN THE CURRENT CODE?Figure 20.Fastener plate/membrane engagement against wind uplift in mechanically attachedWind aerodynamics on a VRA can be viewed as Figure 20.Fastener plate/membrane engagement against wind uplift in mechanically attachedWind aerodynamics on a VRA can be viewed as Figure 20. Fastener plate/membrane engagement against wind uplift in mechanically attached action, whereas the response of the VRA is theThe current code does not address the following:roofing system.roofing system. action, whereas the response of the VRA is the roofing system. reaction. Not all VRAs react to wind in a similarThere is no guide for specifiers to have their reaction. Not all VRAs react to wind in a similar detached from the deck interface, respectively,barrier. Air intrusion can be a major drivingmanner. The response of a vegetated system detached from the deck interface, respectively,barrier. Air intrusion can be a major drivingmanner. The response of a vegetated systemdesign meet or exceed the specified wind as shown in Fig. 22. . force for movement of moisture in the formdepends on several factors, such as the membrane as shown in Fig. 22 force for movement of moisture in the formdepends on several factors, such as the membrane stretched along the deformed plateofwat ter vapornt to a MARS. Fig. 23 s oweddattach ch en ent met d, vegeta etation type, weight,loads.ofwa er vapor i in o a MARS. Fig. 23 sh howe atta m m t metho hod, veg tion type, weight, configurations. Textured hexagonal Q12: IS THERE AN IMPACTthe condensation happening below the roofdesign, and installation method (e.g., edgeThere are no specific climate requirements Q12: IS THERE AN IMPACTthe condensation happening below the roofdesign, and installation method (e.g., edge portion, which results in the mem- plates offer the required contact area OF AIR INTRUSI ION ON Amembrane on one offhe eommerr i al roofs fsrestr st intntnd nditions hehe mple plex win yna yn ic mics OF AIR INTRUS ON ON Amembrane on one o t thc comme cial roo re a rai co co itions). T ). T cocom x wind d d d m a s cbrane being torn as shown in Fig.with the membraneonly throughnon VRAs Asn be s e simplifi ed as eff s due to e tossureurefor materials. The code only provides generic LOW-SLOPE ROOF? during field invest ga at on n.imit itingir intrusionon VRca can b implifiedas effect ects dupre pressLOW-SLOPE ROOF? during field investi ig ti io . L Lim ing a air intrusio20ntrtrusion i wheen he condiitionediindoorthetiical for g andmiddle prctice,ofelelpsand flow. w. Reononsefthe hegetgetd sys syst totoloads that materials are expected to perform Air i (abo on issIf the membrane ndooriscriit outerood roof f designraactice,hhpsand floRespspses osof tve veateatedtememAir inusi ve).whn tthe condtioned tensileiscr cal for good roodesign p rimsitittheaiaienters s into hee buiding envellope assemblyplates. wind uplft and t heermal metale,e,flow includede sliding, overninging,d scouring r r enterinto tth buillding enveope assemblyincrease wind upliift andthrmal r resistnc andflow inclu sliding, overturturn, an and scouring strength was lower than the wind up- increase Smoothcircularesistaancagainst.and c cnnot t esappe o the extterior enviironmentminiimize moisture accu uulation nd(Fig. 26). Respononses the hegetgetd sys syst toto andaannoesccae tto the exerior env ronmentminmize moisture accu mlation aand(Fig. 26). Respses of of tve veateatedtememmlift load, the membrane would stretchplastic plateshave a larger contact w witthe rroof membrane acting as an aircondensat tion ss sues. wi wind- duced prpressure incl ede fatigue an pl ift plift. There is no climate adaptation of future loads.ith h the oof membrane acting as an air condensa ioni is ues. nd-in induced essure includ u fatigue and u du .and tear around the fastenerplates. surface area to increase the bondingThe code does not provide mate rial 16 Fastener Plate/Membrane En- strength with the membrane. January 202516IIBEC InterfaceJanuary 2025 installation requirements. IIBEC Interface gagement in a PARS: The mem- Q11: What Is the Role of brane is adhered to the top surface ofQ20: HOW TO CLASSIFY THE the insulation. The insulation is se- Adhesive, Adhesive Amount cured to the deck with fasteners andand Curing Time? FUTURE CLIMATIC CONDI TIONS plates. Based on SIGDERS research,Adhesive curing time is the keyBE QUANTIFIED?systems with smooth-surface insula- factortodeterminetheadhesiveAs mentioned in Q1, there is a tool available tion plates increased the wind upliftbond strength. The higher the ad- named Climate-RCI that calculates the design resistance by 50-per-cent more thanhesive bond strength, the better theload by accounting for future climatic conditions. systemswithtexturedinsulationwind uplift resistance. For a scenarioIt can be accessed at https://nrc.canada.ca/plates. Fig. 21 illustrates the failuretested by SIGDERS, a system failedFigure 21. Failure modes observed with different insulation plate configurations in partiallyen/research-development/products-services/modes for different insulation platebelow 2.87 kPa (60 psf) with 14 daysFigure 21. Failure modes observed with different insulation plate configurations in partially attached (hybrid) membrane roofing system.attached (hybrid) membrane roofing system. software-applications/climate-rci.Climate-RCI has been developed by NRC. It Since 1935 Q15: IS THERE A TOOL ORWind flow aerodynamics can simulate thetakes into account projected changes in weather Simple to install STANDARD AVAILABLE TOvegetated systems overturning, scouri ng, andelements (wind, rain, and temperature) and Roofing & Sheetpre-grown modularVALIDATE MY VRA DESIGN? sliding failure mechanisms. To mimic the windprovides the design loads for 696 cities across Metal Contractors vegetated roof systems The wind uplift resistance of the VRA can beeffects on the VRA (refer to Q14), both uplift andCanada. The climatic loads are classif ied intoRe-Roofing Specialistsevaluated in accordance with CAN/CSA A123.24,flow testing are needed. three climate zone severity classes: normal,Maintenance & RepairsStandard Test Method for Wind Resistancesevere, and extreme. This tool also forms partIndustrial & Commercialof Vegetated Roof Assembly. The test resultsQ17: CAN I USE THE WINDof CSA A123.26, Performance Requirements can be compared to the calculated designUPLIFT DATA FROM A ROOFfor Climate Resilience of Low Slope Membrane parameters in Q4 above for pass/fail scenarios. SYSTEM TEST? Roofing Systems.Yes, in a scenario where the VRA has the same Q16: WHY ARE VRASroofing system as the one tested under CAN/CSAQ21: CAN FUTURE WEATHER SUBJECTED TO UPLIFT ANDA123.21, Standard Test Method for the DynamicSHOCKS BE MODELLED FOR FLOW RESIS TANCE TESTS? Wind Uplift Resistance of Mechanically AttachedROOFING AND OTHER BUILD-An uplift test only evaluates the pressureMembrane-Roofing Systems, the manu facturerING ENVELOPE MATERIALS?ITS THE WORKMANSHIPresistance of the VRA, since the membrane actsor client may choose to use the uplift resistanceBased on discussions with the industry, THAT COUNTS as an air barrier in a conventional roofing system.data obtained from CAN/ CSA A123.21. Then thea framework was developed using future 220 Norseman St.,Toronto, ONM8Z 2R4 January 2025IIBEC Interface17Tel: 416-239-3594Fax: 416-239-9891 liveroof.cajseeback@seeback.com 519-671-5777www.seeback.comORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWSISSUE 1 202519'