b'Forming a ConsortiumBuildingenergycodes,suchastheInternationalEnergy Conservation Code and the National Energy Code of Canada for Buildings, provide minimum performance requirements for the design of energy-efficient roofs. But none of these have any design considerations for thermal impact factors, namely thermal bridging and bypass. The prescriptive requirements in codes and standards mainly have focused on insulation re- Figure 3: Design insulation nominal thickness for achieving respective R-value.quirements with limited emphasis on the thermal impact fac-tors and their effect on energy loss. Reasons for the omission could include the absence of data and a lack of clear informa- Protective Roofing tion demonstrating the significance of thermal bridging and bypass.To enhance the energy efficiency of low-slope roof systems,Safety Productsthe National Research Council Canada (NRC) developed an industry consortium, Energy Resistance of Commercial Roofs, whosepartnersinclude2001Company,Waterbury,Conn.; CanadianRoofingContractorsAssociation;EPSIndustry Alliance; International Institute of Building Enclosure Con-sultants; Natural Resources CanadaProgram of Energy Re-search and Development; NRCA; Rockwool, Milton, Ont.;BYRoofing Contractors Association of British Columbia; Sika Sarnafil, Canton, Mass.; SOPREMA Inc., Drummondville, Qubec; and TRUFAST, Bryan, Ohio.The consortium developed a project that had two major tasks:Evaluate the effective thermal resistance of current roofsystem designs and validate their compliance with energy code requirements using large-scale testing.Quantify thermal bridging from metal fasteners and ther- mal bypass from gaps between the insulation boards.Following is an explanation of some of the experimental work conducted at NRC to quantify the implications of ther-mal bypass occurring because of gaps at the joints between insulation boards. The PR 100 Guardrail SystemSetting Parameters is an efficient and practical perimeter guardrail that allows youWhenselectingtheroofassembliesandcomponentstoto work right to the edge of the roof.be evaluated, we had to determine the thermal transmittance Meets and exceeds OSHA & WCB requirementsof roof assemblies that are designed to comply with the en-Accommodates: parapets and cant stripsEasy to installergy codes prescriptive requirements. A three-step approach Provides unobstructed access to roof edgeachieved this.In the first step, the prescriptive thermal transmittance re-quirements for roofs as specified in the National Energy Code of Canada for Buildings and ASHRAE 90.1-2013, Determina-tion of Energy Savings: Quantitative Analysis, were summa-rized and consolidated into three categories: R-26, R-31 and R-36. It should be noted R-26, R-31 and R-36 are effective R-values that include outside and inside surface air films. Energy codes require that roof assemblies be designed to meet these minimum effective R-values to attain specific levels of energy efficiency. This design is achieved using R-values of the com-ponents measured at a standard average temperature of 75 F. The PR 600 Mobile Fall Protection SystemNext,theconsortiumssteeringcommitteemembersse- can be moved along the roof by pulling the cart to the desired working location, lected three common conventional low-slope membrane roofproviding a safe working area. The PR 600 meets O.S.H.A. compliance 1926.502D.assemblies, including three different conventional insulations: expanded polystyrene, polyisocyanurate and stone wool. Us- Roofing & Sheet Metal Super Service Centresing the insulation R-values per inch provided by the manu-facturers, the overall insulation thicknesses (top and bottomEDMONTON, AB CALGARY, AB WINNIPEG, MB WESTON, ONlayers) for these three design categories were determined by the(780) 432-2786 (403) 255-8236 (204) 338-7613 (Weston Road)steering committee as shown in Figure 3. (416) 745-4111All the selected assemblies contained two insulation layers.BARRIE, ON HAMILTON, ON TORONTO, ONThe most common layout for the assemblies installed with two(705) 792-6683 (905) 560-2858 (416) 534-8421 WESTON, ONlayers of insulation is a configuration where the joints betweenOAKVILLE, ON PICKERING, ON LONDON, ON (Signet Drive)the insulation boards are not lined up vertically but are in a(905) 825-0034 (905) 426-4443 (519) 668-3626 (416) 744-2050staggered alignment, referred to as staggered joints. The studys primary focus was to quantify the thermal bypass resultingwww.sparmarathon.cafrom gaps at the staggered joints.ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWSISSUE 1 202113'