b'brane lifting and peeling or pullingVegetated Roof Assembly, 15to de- the ability of the system to evacuatesign process involves determining theoff rainwater from the most intense away from the roof perimeter. Thetermine the project-specific windthewater. appropriate number of drains and sizerainfall that is likely to occur. There-required use of metal componentsupliftloadsandairflowcondi- Theprimaryfunctionofaroofof drains and scuppers, taking into ac- fore,tomeetcurrentcoderequire-to secure membrane terminationtions for either the built-in-placeassemblyistopreventprecipitationcount the roof slope, the type of roofments (which would be applicable to to the structural elements such asvegetated systems or the modularfrom entering the space below by con- finish and the type of rainwater lead- a Bronze project), the designer needs metal decks may cause some ther- vegetatedsystem.Theintentoftrolling and discharging the rainwaterers.Thenumberandsizeofdrainsto determine the maximum 15-min-mal bridging around the fasteners.thetestistoevaluatetheover- collected on the roof to either a stormarecalculatedbasedontherainfallute rainfall intensity for the site loca-However, the risk of wind upliftturningand/ordisplacementofwater drainage system or the terraininformationfromNBCC 2 andthetion (one-in-10-year return), referred failuresandconsequentialrepairthevegetatedroofcomponentsadjacenttothebuilding.Toensuremaximum permitted hydraulic load ofto as the concentration time. This orreplacementofroofassemblymountedontheroofassemblythat roof assemblies meet this objec- leader pipe available in OBC. 3 rainfall information can be obtained trumpsthemarginalincreaseofsamples when wind uplift loadstive, designers calculate rain loads andThe intent of the code is to ensurefrom Table C-2 in the NBCC 2Ap-thermalbridgingattheroofpe- are applied. design a roof drainage system. The de- that the roof drainage system can carrypendix or the Ministry of Municipal rimeters.Anotherpossiblechal- Whenthereareexterior-lenge with the installation of termmountedrooftopunitssuchasProtective Roofing bars and plates is the potential in- mechanical,electricalandcom-hibition of rainwater drainage. Asmunicationsequipment,airin-an alternative to the requirementtakes,ventstacks,guywiresor Global WarmingClimateWind PressureFactored Wind UpliftResiliencyRequiredto install the term bar and plates,solar panels, the attachments forSafety Productsthestandardincludesanoptiontherooftopunitsandthesup-Magnitude Severity forValue Load Index Performanceto further increase the wind upliftporting frames can be insucient Wind Level for Wind loads for the perimeter zones by 30or missing. When the wind uplift per cent for parapets with a heightload exceeds the self-weight of a Source: Climate-RCI 13 Source: Wind-RCI 7 Source: Climate-RCI 13 greater than 914 mm (3 ft.) and 50rooftop unit, the unit could tip per cent for parapets with a heightover, causing damage to the roof 1 Bronze lower than 914 mm (3 ft.).membrane. While CSA A123.26 5 BYCorner -2.6 kPa Windupliftloadsaresignifi- includessomeprescriptivere-0.5C Normal 0.44 kPa Edge -1.3 kPa 2 Silver cantatparapets,particularlyatquirements for the anchorage of thetopedges,whichexperiencerooftop units, the main intent is Field -1.0 kPa complex wind aerodynamics. Capto design rooftop units, including 3 Gold flashings,includingcleatsandtheir components and anchorage, their fasteners, require an appro- to meet the wind uplift loads re-1 Silver priatethicknessandattachmentquired for the roof assembly. Corner -2.7 kPa spacingtoresistthedeterminedCSA A123.26 5also addresses 2C Severe 0.46 kPa Edge -1.4 kPa 2 Silver windupliftloadrequirementsan issue related to the rubbing of Field -1.1 kPa as that of the roof assembly. Therooftop components against the 3 Gold windforcesontheparapetandroofmembranesystemcausing cap flashing are complex and de- reduced service life. The standard 1 Gold pendontheroofslope,parapetrequires that gas lines are mount-Corner -2.9 kPa height,parapetshapeandinter- ed on supports at a minimum of 3.5C Extreme 0.5 kPa Edge -1.5 kPa 2 Gold nal pressure between the wall and304 mm (12 in.) over the mem- 2 x 4 Wood Rails 8 Aluminum Railsedgemetal.Thecapflashings,brane surface to limit the poten-Field -1.2 kPa particularly at the corners, have atial for gas lines to rub against theThe PR 100 Guardrail System 3 Gold high probability of failure, whichroof membrane due to deflectionsis an efficient and practical perimeter guardrail that allows youNote: Above values are for a roof with no parapet. can lead to further failure of thebetween the supports. Similarly,to work right to the edge of the roof.rest of the flashing, other parapetthe standard requires that light-Meets and exceeds OSHA & OHSA requirementscomponentsandthemembraneing protection cables are secured Accommodates: parapets and cant strips of the roof system. In addition toto thermally non-conductive sup-therequirementslistedinCSAporting elements to limit rubbing Provides unobstructed access to roof edgeEasy to installA123.26, 5 refertoANSI/SPRIof the cables on the roof mem-ES-1, Wind Design Standard forbrane.Theminimumspacing Edge Systems Used with Low Sloperequirements for the securement RoofingSystems, 14 forfurtherof cables are 914 mm (36 in.), 304 guidance. The CSA A123.26 5re- mm (12 in.) and 203 mm (8 in.), quires that the membrane flashingrespectively, in the field, edge and be fully adhered on the vertical up- corner areas. turn of the parapet and wrappedCSAA123.26 5 addressesthe over the top edge of the parapet,commonissueofcorrosionof with fasteners securing the mem- metalcomponentsinrooftopThe PR 600 Mobile Fall Protection System braneflashingthroughcleatstounits and resulting damage to thecan be moved along the roof by pulling the cart to the desired working location,limit failure. roof membrane by requiring thatproviding a safe working area. The PR 600 meets O.S.H.A. compliance 1926.502D.rooftopunitsandtheircompo-Rooftop Add-Ons nents, including body stands, an-Acriticalissuerelatedtothechors and fasteners, be made outRoofing & Sheet Metal Super Service Centresrooftop add-ons is their resistanceofnon-ferrousmetals,stainless to wind uplift loads. With regardsteelorhot-dipgalvanizedsteelEDMONTON, AB CALGARY, AB WINNIPEG, MB WESTON, ONto the design of rooftop add-ons,with a coating designation of at(780) 432-2786 (403) 255-8236 (204) 338-7613 (Weston Road)CSA A123.26 5requires that add- least G-90. (416) 745-4111on components and their anchor- BARRIE, ON HAMILTON, ON TORONTO, ONagesmeetthewindupliftloadResistance to Rain Load (705) 792-6683 (905) 560-2858 (416) 534-8421 WESTON, ONrequirements for the roof assem- Rainwater resistance of a roofOAKVILLE, ON PICKERING, ON LONDON, ON (Signet Drive)bly. For vegetated roof assemblies,assembly is a function of the wa- (905) 825-0034 (905) 426-4443 (519) 668-3626 (416) 744-2050CSAA123.26 5 referencesCSAtertightness of the membrane and A123.24,StandardTestMethodflashings,theroofslope,drain- www.sparmarathon.cafor Wind Resistance of Modularage,flashingconstructionand ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWSISSUE 3 202519'