Fire resistance of timber decking for heavy timber construction

The National Building Code of Canada provides both prescriptive specifications for timber beams and columns afforded equivalency to wood-frame construction with 45 min fire-resistance ratings, and simple calculation methods for determining fire-resistance ratings of larger glued-laminated timber beams and columns. However, the building code does not accept calculation methods for determining the fire endurance of mood decking materials. Although heavy timber roof construction is quite common in construction projects today, the use of heavy timber floor construction is not. The fire performance of floor and roof decking in heavy timber construction is, however, a critical concern in the renovation of older buildings. The authors receive more enquiries about the fire resistance of specific deck combinations, and how to increase the fire resistance of these building elements, than about any other fire-resistance related subject. The inability of the wood industry to respond to these enquiries with accurate information almost always results in costly wood solutions or the selection of non-wood alternatives for renovation projects. This paper addresses many of those questions.