Sawdust based insulation has many benefits, which allow for moisture safer structural solutions, that are also eco-friendly, healthy and industrially producable. Sawdust based insulation has a high moisture capacity, which reduces the risk of moisture damage in the structure during use, improves the fault tolerance if air leakage occurs, and reduces the need to use anti-mildew compounds and chemicals. Since the insulation is wood based, it also lowers the carbon footprint of structures, which can be used to compensate for the lower thermal insulation capacity.
In the ECOSAFE-project the hygrothermal performance of sawdust based structures is studied both experimentally and by calculation. Additionally, the requirements for making the structures moisture safe without anti-mildew compunds or a vapour barrier are studied in current and future climate conditions. During the analyses the hygrothermal performance of the sawdust insulated structures is compared to that of current energy efficient structures. The structures included are exterior walls, roofs and base floors from both single-family houses and larger timber-frame buildings. During the project, building physical material properties are also determined for the sawdust based insulation materials, so that their hygrothermal performance can be analysed more accurately by calculation. As a result of the study, recommendations and structural solutions are complied for building moisture safe sawdust insulated structures.
During the project the carbon footprint of sawdust insulated external structures is compared with that of structures, which fulfill the current energy efficiency regulations. The U-value requirements needed for the carbon footprint of sawdust insulated structures during their lifetimes to be lower than that of current energy efficient structures are determined. The analyses are done using the Ministry of Environment’s new calculation method for the carbon footprint of a building during it’s lifetime. As a result of the study recommendations for the reference U-values of these structures are determined.
The ECOSAFE 2 project examines the beneficial effect of claying on the functionality of cutter insulation, as observed in the ECOSAFE project. The study complements the ECOSAFE studies and expands the research to the areas of acoustics, fire technology and microbiology. In acoustics, the acoustic properties of cutter chip insulation and clay cutter plaster are studied and computational determination of the acoustic properties of different types of structures is performed. In fire technology, the fire resistance of clay cutter chip insulation is determined and the fire compartmentality of the structure is also determined when the structure has been implemented entirely with wood and clay-based products. Microbiology, on the other hand, studies the effect of claying on the microbiological function of cutter chip insulation. Based on the studies carried out, the recommended structural solutions of the ECOSAFE project will be amended and supplemented as necessary.
The ECOSAFE and ECOSAFE 2 projects will be reported as a single entity in the final report to be published in the spring and summer of 2023, which will bind the research parts carried out in the projects into a coherent whole and include the types of recommended structures and their justifications.
The duration of the project is 2019–2023.
The ECOSAFE and ECOSAFE 2 projects have received funding from the Ministry of the Environment’s wood construction programme. The aim of the wood construction programme is to increase the use of wood in construction to promote climate goals. In addition, the ECOSAFE 2 project has been funded by several companies and the University of Tampere.