b'PHOTOVOLTAICS Planning for photovoltaicsNoteveryroofissuitableforaPV array, and because a rooftop photovol-taic system represents a huge monetary investment,everyowneranddesigner shouldpressthe"pause"buttonand consider the costs and benefits of each designelement.Newroofscanbe designed to accommodate PV systems, butexistingroofsposechallenging considerations. Consider the age of the roof before adding a PV system. Even if the roof is only a few years old, it may run its course well before the PV systems needs any upgrading; replacing a roof when a PV system is perfectly func-tional could be unaffordable. To find out what is realistic, hire a qualified roofing professional to survey the condition of the roof, identify any necessary upgrades and repairs and evaluate its suitability for a PV system. Ideally, any new PV systemsecurement,roofdrainage,theroofflatroofsoftenofferthemostusable should be installed at the beginning of asystemandrooftopmaintenance,andspace; water-shedding roofs are fixed in roof systems service life, so that the twoincludeappropriatelylocatedpenetra- theirslopeorientation,whichrenders systems age together. tions that link the arrays output capacitysome of them unsuitable. Furthermore, PHOTOVOLTAICS The structural capacity of any rooftothebuildingselectricalsystemaroofthatservesasaplatformwill cannot be overlooked. New roof designwithout compromising the purpose andrequiresomeenhancementstoensure will most certainly account for both thecapability of the roof. 1 it performs optimally during its service dead loads and live loads of the PV array,life. Refer to Part 14 THE ROOF as but existing roofs may require a soberDesign considerations aPLATFORMpublishedinthein ON ROOFS evaluationandaplantoenhanceitsPV arrays can be installed on virtually anythe RCABC Roofing Practices Manual load capacity. Consult the local authoritytype of roof, but not every type of roof(RPM),inanyoftheWaterproofing havingjurisdictionfortheirstructuralis suitable for a PV array. Waterproofingstandards for roofs.requirementsandaregisteredprofes- roofs (also referred to as flat or lowEffectivethermalperformanceis sional skilled and knowledgeable aboutsloperoofs)offerthebestplatformbothdesirableandrequiredbyCode, roof structural design. becausePVarrayscanbeorientedbut this can be significantly undermined Seek a balance between the func- toward the sun more easily, and becauseby structural supports and by mechan-tion of the roof and the desired output1 The 2010 Technical Bulletin by the Canadianicalfastenersusedtosecuretheroof ofthePVarray.AgooddesignwillRoofing Contractors Association, Photovoltaicssystematorimmediatelybelowthe in Roofing, offers an excellent treatment of harmonizetherequirementsforPVthese issues (https://roofingcanada.com). membrane(fastenersincontactwith Cladding PlumbingFabrication Process PipingGas Fitting RoongIndustrial Construction Roong SystemsIndustrial MaintenanceStructural SteelMachining & Millwrighting Sheet Metal & HVAC Phone: 250.632.6859|Email: 101first@cimsltd.com245 3 rdSt, Kitimat, BCV8C 2N8www.101industries.comwww.rcabc.org l27'