School of Chemical Technology Degree Programme of Forest Products Technology

There has been a growing interest in cascading materials recovered from buildings as the amount of construction and demolition waste (C&DW) has been increasing. In Finland, cascading wood from building can be one of the effective approaches considering that there are a lot of wooden buildings, which are now due for renovation or demolition. From this point, investigating the available amount, as well as the potential for cascading, is significant. However, the statistics available to discuss the potential are limited at the moment. Therefore, this study aimed to obtain the required data through a case study of a building demolition and to analyze the potential of cascading wood from the building. The case study building was a wooden building (Kindergarten) in Porvoo. The possible amount for cascading was calculated before the demolition and compared with the amount after the demolition. Following this, the wood recovered from the building was assessed from different perspectives. Through the data gathered, the potential amount for cascading was obtained and the amounts were compared in terms of the cross-section and the location where each recovered wood piece was used. The results revealed that each recovered wood piece showed different behavior in the extent of damage, regardless of the dimension. In addition, wood with better condition was recovered in the independent parts such as the roof and exterior cladding, which also showed different behavior by location. These results indicated that the cascading potential for recovered wood should be discussed in terms of both cross-section and location. Through the further investigation, even smaller cross-section such as the 1”× 4” from the roof board and the 1”× 4” and 1”× 6” with paint from the exterior cladding showed a high cascading potential thanks to the reasonable recovered condition. Moreover, it could be observed that the paint was not necessarily critical for cascading unless it is hazardous. These results demonstrated the potential of the extension of a target for cascading recovered wood not only to wooden building but also other types of buildings with concrete or steel structures. It was also discussed that technological aspects such as the demolition method and building design extensively affected the potential. At the same time, however, it was suggested that minor changes in the details could be applicable to improve them for the enhancement of the potential. To raise the reliability of the results from this study, more case studies with different types of buildings were recommended. In addition, more accurate cost comparison and environmental assessment including whole lifecycle would be beneficial to drive the industry in the direction to cascading more materials recovered from building in general.