Wood fibre insulation is a product that is widely used in Europe but is only just catching on in North America (as of 2023, TimberHP in Maine, USA is the only factory to begin producing WFI). WFI is produces by taking chipped waste wood (traditionally in the form of mill waste from softwood lumber mills) soaking it in water and a pressurized steam bath to soften the bonds between the fibres before it is ground up and dried into a fluffy wool-like product. It can be used as is in its processed state as a blown-in insulation, or it can be combined with adhesive fibers or liquids to create flexible batt insulation or rigid exterior insulation. The rigid insulation board performs similarly to rockwool and the addition of certain waxes during the mixing process makes it fully waterproof. The boards are milled with tongue and groove profiles so that when properly installed the wood fibre insulation acts as an air and weather resistant barrier. It is also vapour permeable, meaning that it does not trap moisture to allow mould formation.

While the process for making WFI is well established and well-optimized, the specific fibre making technology is only accessible in Europe making prototype-scale research challenging. Our intent is to assess the viability of C&D waste wood as a feedstock for fibre production, and to include as diverse types of waste wood as possible including so called “dirty-wood” such as engineered wood products. This may be down through traditional productions methods or we may adapt technology from other fibre-based products to create our materials. Our goal is to show that western Canada has all it needs to take the plunge into wood fibre insulation production and that using salvaged wood as a feedstock for value-added construction products is commercially viable. Our research will also look at alternatives to the traditional petrochemical adhesives and treatments (such as PMDi resin, nylon, and paraffin) to enhance the environmental benefits of the products.

Pavatex wood fibre insulation installed on a deconstructable wall assembly. The WFI board used in this project was generously donated by International Timberframes Inc.