Recent architectural trends include the design and construction of increasingly tall buildings with structural components comprised of engineered wood referred to by names including; cross laminated timber (CLT), laminated veneer lumber (LVL), or glued laminated timber (Glulam). These buildings are cited for their advantages in sustainability resulting from the use of wood as a renewable construction material.
Research and testing are needed to evaluate the contribution of massive timber elements to room/compartment fires with the types of structural systems that are expected to be found in tall buildings (e.g. CLT, etc.). Previous research has shown that timber elements contribute to the fuel load in buildings and can increase the initial fire growth rate. This has the potential to overwhelm fire protection systems, which may result in more severe conditions for occupants, fire fighters, property and neighboring property.
The contribution of timber elements to compartment fires needs to be quantified and compared against other buildings systems to assess the relative performance. The contribution of exposed timber to room fires should be quantified for the full fire duration using metrics such as charring rate, visibility, temperature and toxicity. This will allow a designer to quantify the contribution, validate design equations and develop a fire protection strategy to mitigate the level of risk to occupants, firefighters, property and neighboring property. In addition, the effect of encapsulating the timber as means of preventing or delaying involvement in the fire (e.g. gypsum, thermal barrier) needs to be characterized.
Daniel Brandon and Birgit Östman, with the SP Technical research Institute of Sweden, have published the latest report on this issue through the Fire Protection Research Foundation. Their report is part of a larger project with the goal to quantify the contribution of CLT building elements in compartment fires and summarizes the literature on previous CLT compartment testing. Read the full report by downloading it free of charge.