Over the past several decades, the market for ready-to-assemble (RTA) products has grown significantly. RTA kitchen cabinets and furniture are commonplace because they can be shipped flat and assembled on site, which has greatly reduced shipping costs associated with an otherwise voluminous product. Packaged with necessary hardware and instructions, these RTA products are typically easy to assemble and fool proof. The development of a standardized safe room using CLT that is ready to assemble, easy to ship, and quick to fabricate on site would not only increase the level of safety for our population but also increase the market opportunity for these engineered wood products. This research is an extension of research by the USDA Forest Service, Forest Products Laboratory, to develop a do-it-yourself safe room constructed from wood that can be incorporated into existing housing and that utilizes commodity wood products.
The objective of this project is to develop a RTA tornado safe room and shelter from CLT for use in existing and new residential and commercial construction.
In this paper, we examined the effects of extreme tornadic wind loads on mass-timber buildings. In general, mass-timber buildings utilize pre-engineered wood panels to form their main gravity and lateral load resisting systems. The lightweight nature of timber makes these types of emerging buildings lighter and more flexible than buildings made from concrete, masonry or steel. In general, global lateral instability of buildings can occur when the overturning forces due to wind loads exceed the dead load of the structures. In the present study, wind loads were obtained from laboratory simulations of tornado-like wind field and atmospheric boundary layer flow at Western University, Canada. Tornado wind loads from the laboratory tests were scaled to five Enhanced Fujita wind speeds representing various levels of damage. Dynamic structural analyses were carried out to assess floor level demands. It is shown that extreme tornado wind loads may pose significant damage to mass-timber buildings designed for 1-in-50 wind speed using a load factor of 1.4. Based on the obtained results, design strategies are suggested for mass-timber buildings in tornado-prone areas.