b'the steel deck. However, in reality, the installed penetration lengths fall short of the standard practice. The effect of the penetration depth on the overall thermal performance of the roof assembly is evaluated by testing three different fastener lengths of #14 (6 in., 7 in. and 9 in.). The testing was conducted on R-26 polysio roof assemblies (overall thickness = 127 mm [5 in.]) to ensure penetration depths of 25, 51 and 104 mm (1, 2 and 4 in.) below the deck, as shown in Figure 9. The fas-tener density was maintained at 2.69 fasteners/m 2(0.25 fasteners/ft. 2 ).Figure 10 summarizes the effect of fastener penetration depth. The two fastener penetration depths of 51 and 102 mm (2 and 4 in.) showed an average of 0.2 per cent variation in thermal performance compared to the standard practice of 51-mm (1-in.) depth below the steel deck. Therefore, it was established that the fastener penetration depth had a minimal impact on the effective R-value of the roof assembly.Effect of Fastener AreaThe fundamental heat flow relationship states that the heat flux is directly proportional to the area of the surface, perpendicular to the direction that heat is flowing. Relating the heat flux theory to the fastener area, three common commercial roofing fasteners were evalu-ated. The fasteners included #12, #14 and #15, with shank diameters/ Figure 12: Effect of fastener diameter.area of 5.4 mm/23.2 mm 2 , 6.0 mm/28.4 mm 2and 7.1 mm/40.0 mm 2(0.214 in./0.036 in. 2 , 0.237 in./0.044 in. 2and 0.280 in./0.062 in. 2 ), re-spectively (Figure 11).The testing was conducted on two design categories: R-26 and R-31, with the three insulation types maintaining a constant fastener den- performance, on average, by 7 per cent compared to the roof assembly installed with #12 fasteners. In the sity of 2.69 fasteners/m 2(0.25 fastener/ft. 2 ). Figure 12 shows the dataR-31 design category, roof assemblies with #14 fasteners measured on average 12 per cent lower thermal summary for the fastener diameter effects. Irrespective of the insulationperformance compared to the roof assembly installed with #12 fasteners. The #15 fasteners, which had type, the data showed that the fastener area had an impact on the overall thermal performance of the roofing assemblies. In the R-26 category,almost 40 per cent more conductive area than #14 fasteners and 70 per cent more area than #12 fasteners, two fastener types#12 and #14were tested. The #14 fastener hadincreased the thermal bridging on average by seven per cent and 18 per cent, respectively. Thermal bridg-30 per cent more heat transfer area than #12, which lowered the thermaling increases with the increasing fastener diameter/area were observed from the measured data.EVERYTHING YOU NEED FOR YOUR ROOFING & BUILDING ENVELOPE PROJECTS.Dynastywith ArmourZone Performance Shingles Ener-AirPolyiso InsulationASK US ABOUT OUR DELIVERIES!WWW.ROOFMART.CAORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWSISSUE 1 202025'