b'Cold Storage FacilitiesThe Cold, Hard Facts Cold-storage facilities require unique roof system installation guidelines By Matt Dupuis, PhD, P.E.F acilities with cold interior en-vironments store cold goods, housefood-processinglines andhaveamultitudeofother uses.Whenconstructingaroof system on a cold-storage facility, workmanshipandattentionto detail are critical. A tiny air leak that would be of little to no con-sequence in a roof system on an office building can lead to mois-tureand/oriceformationona cold-storagefacility,aswellas endless service calls from the fa-cility owner. Understandingspecialdetails and tolerances required for cold-storagefacilitiescanhelpwhen designingandconstructingroof systems to meet these challenges, which become greater the colder the interior environment.Overall Design ApproachRefrigeratedenvironments (coolers) range from above 32 F to below -10 F for deep freezers, and in some cases, blast freezers canapproach-50Fforinterior temperatures. There are three ba-sicdesignapproachesforcold-storage facilities.Thefirstmethodistobuild the envelope for the cold environ-ment within the standard build-ing envelope. This is the most ex-pensive method but leads to the greatest chance for success. Also knownasthenestedapproach, conceptually similar to a Russian nesting doll, this technique is seen atgrocerystores,convenienceThesecondandmostcom- ingbuildingbyconvertingtheMoisture Flow and tunately, roof membranes almost stores and even your home with amon technique is to construct theinterior to cold storage. As withVapour Retarders always are great vapour retarders. refrigerator-freezer.Thisconceptbuilding envelope as the exterioranythinginconstruction,withButinacold-interiorenviron-can be scaled up to hundreds ofenvelope of the cold-interior en- enoughmoneyandplanning,In cold-storage facilities, mois- ment facility, the roof membrane thousands of square feet for largevironmentfacility.Thewallsofanythingcanbeaccomplished.ture vapour flow is reversed fromis on the warm exterior side; a va-commercial food distribution forthis type of construction typicallyHowever, adding insulation to thea traditional building in a north- por retarder in its typical position grocery chains. In these distribu- aremadefrominsulatedmetalwalls and roof and then bringingernclimate,includingtheroof.on the roof deck is of little value tion centres, dry, refrigerated andpanels and provide challenges inIn this situation, the water vapourandcan,anddoes,causeprob-frozen goods are housed in oneroofedgedetailing,butcarefulinrefrigerationequipmentdoesontheoutsideofthebuildinglemsincold-interiorenviron-building up to and well beyondworkmanship can make this de- not address all the considerationswill, by vapour pressure differen- ment facility roof system designs.1 million square feet. One of thesign approach a successful one. that go into a trouble-free refriger- tial,moveintothecold-storageManyproductsusedinroof many benefits to this approach isThethirdapproachinvolvesated space, let alone deep-freezebuildings interior. systemshavevaryingwaterva-the roof system requires no par- convertinganexistingbuildingbuildings. I recommend avoidingTo prevent moisture from get- pour retarding capabilities (perm ticularlyspecialtechniquesorinto a cold interior environmentthese types of roofing projects be- ting in and condensing, a vapourratings). When moving from the details. Repairs and reroofing alsofacility.Typically,theownercause when they fail, they do soretarder needs to be placed on theexterior to the interior of a cold-are substantially easier. will buy and repurpose an exist- spectacularly. building envelopes exterior. For- storage facility, various layers of 8ONTARIO ROOFING NEWSISSUE 4 2019/2020 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'