b'WOOD AS DECKING COMPONENTSAPPLICATION OF WOOD ASTHE DECKING COMPONENT FOR A COMMERCIAL BUILDING WITH MECHANICALLY ATTACHED MEMBRANE ROOFSBy Dr. A. Baskaran, P.Eng., F-IIBEC,National Research Council Canada, bas.baskaran@nrc-cnrc.gc.caT he majority of residentialand 100ksi, respectively, representingfastened to the structural deck (steel or homes have wood as thethe Canadian and U.S. market werewood) by keeping all the above-deck decking component as part ofincluded in the experimental programcomponents and method of applica-the roof assembly. The use ofto compare the roof assemblies windtion of various components the same. wood as the decking compo- uplift resistance side by side with threeSystem experiments were carried out nent in commercial roofsdifferent of wood decks, namely 5/8by constructing 12 x 24 mock-ups can be attractive due to its easy instal- OSB,plywood and 5/8 plywood.that were constructed and cured as lation and cost effectiveness. In NorthSystems were investigated with variousper the manufacturers instructions America, the market share of deckmembrane types that were mechanicallyand subjecting it to the CSA A123.21 wood varies and mainly depends on the geographical location, with dominance in the west coast compared to the rest of(a) Small scale the country. Specimen 16 x 16 Recently, SIGDERS completed anCSA Load Cycleextensive investigation by carrying out dynamic wind uplift experiments on membrane roof assemblies that use#15 Fastener #14 Fastenerwood as a decking component. The main objectives of this investigation are:S1 S2 S3 S5 S2 S3 S4 1. To find out what type of wood is acceptable to use as a deckingSteel Deck Wood Deckcomponent in commercial roof applications; and 40 ksi 100 ksi 5/8" OSB 1/2" Plywood 5/8" Plywood2. If wind uplift resistance data is available from tested roof assem-blies that had steel as their decking component, then how can the wind(b) System uplift resistance be estimated for the same roof assembly by substitutingMock-up 12 x 24 the deck component from steel toWood vs. Steelwood without performing full-scale testing?40 ksi 100 ksiAn experimental program was devel-oped (Fig. 1) to carry out small-scale and system investigations under5/8" OSB 1/2" Plywood 5/8"Plywood 5/8" OSB 1/2" Plywooddynamic loading. Samples and systems were constructed with two commonly used fasteners from various sources.Mod Bit EPDM Mod Bit EPDM TPO PVCTwo different grades of steel decks with Figure 1: Experimental program for small scale and system test minimum tensile strengths of 40ksiFIGURE 1: EXPERIMENTAL PROGRAM FOR SMALL-SCALE AND SYSTEM TEST.SPRING/SUMMER 2025 17'