Combined fire retardant and wood preservative treatments for outdoor wood applications - A review of the literature

A collaborative Australian national project funded jointly by the Commonwealth Scientific and Industrial Research Organisation and the Forest & Wood Products Research and Development Corporation has been undertaken to develop a 'proof of concept' for a combined. re retardant/wood preservative treatment technology for P. radiata to satisfy the requirements of both the Australian Bush. re and Wood Preservation Standards. The focus of the work was on products that found use in exposed outdoor, above-ground applications. This paper reviews the literature currently available regarding the impregnation of wood with chemical systems that offer resistance to both. re and biodegradation and are also suitable for exterior applications. We have found that in general, researchers have chosen to utilise the dual functionality of boron compounds to achieve both. re retardancy and wood preservation. Often, such systems are applied in multi-step processes, which involve an impregnation step followed by a curing step. Because of the leaching problems associated with boron, a great deal of effort has gone into the development of systems which. x the boron into wood so that its preservation properties can be maintained throughout the useful life of the material.