Life-cycle assessment of prefinished engineered wood flooring in the eastern United States

Abstract

This study conducted a cradle-to-grave life-cycle assessment (LCA) of engineered wood flooring manufactured in the eastern United States. System boundaries in this study included the following information modules: raw material extraction (A1), raw material transportation (A2), product manufacturing (and packaging) (A3), product transportation (A4), installation (A5), product use (B1-B7), and end-of-life (C1-C4). Two disposal options were considered for flooring products at the end of useful life: landfilling and burning. The burning option captures heat, which displaces use of natural gas. A functional unit of 1 m² of flooring with a weighted average oven-dried mass of 18.9 kg/m² of flooring (for 75 years of estimated service life of the building) was used to present the LCA results. Surveys collected primary data along the supply chain including resource procurement, manufacturing, and logistics. The use and disposal stages of the flooring products were modeled with data from literature and industry experts. This LCA study followed the guidelines of the International Organization for Standardization standards and product category rules (Underwriters Laboratories-Environment Part A + Part B: Flooring EPD Requirements). Life-cycle impact assessments (LCIA) were estimated using the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts, CML baseline, and cumulative energy demand. Among all segments of the life cycle (cradle-to-grave), the contributions of the use stage and, to a lesser extent, the product manufacturing module dominated the total cradle-to-grave environmental impacts of engineered wood flooring. The cradle-to-grave LCIA results showed that 39.3 kg CO₂eq were released during the life cycle of 1 m² of engineered wood flooring. Considering biogenic carbon emissions (i.e., carbon sequestration), the net global warming potential impact was decreased to 16.4 kg CO₂eq because carbon is stored in the landfill (82% of total waste disposed of in landfill). Each square meter of engineered wood flooring consumed 840.2 MJ of energy, and about 25.5% of the total primary energy used came from renewables, specifically on-site woody biomass. This study showed that engineered wood flooring can be considered a carbon-negative material that stores carbon (22.85 kg CO₂eq/m² flooring) for decades and thus can help to mitigate climate change.

Citation

Heidari, M. Davoud; Bergman, Richard D.; Salazar, James; Hubbard, Steven S.; Bowe, Scott A. 2023. Life-cycle assessment of prefinished engineered wood flooring in the eastern United States. Research Paper FPL-RP-718. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 34 p. https://doi.org/10.2737/FPL-RP-718.