Plywood Usage and Wastage in Slab and Beam Formwork: Evidence from SME Construction Projects in Sri Lanka

Plywood is widely used in reinforced concrete construction for slab and beam formwork, but its temporary nature results in significant material wastage that remains under-researched in SME construction projects in Sri Lanka. This study examines plywood usage and wastage patterns in slab and beam formwork within five SME construction projects, using a qualitative multiple case study approach based on semi-structured interviews with project managers, quantity surveyors, technical officers, supervisors, and formwork carpenters. Cross-case analysis identified usage practices, waste generation patterns, reuse strategies, and management challenges across the projects. Respondents estimated plywood wastage at approximately 5–10%, with offcuts from cutting operations reported as the dominant waste type, and boards typically reused 3–4 times before disposal. Labour handling, stripping practices, inadequate supervision, and storage constraints were identified as the main perceived causes of waste. Wastage was rarely measured directly; most projects instead relied on assumed allowances during procurement. The findings point to improved supervision, material handling, storage, and cutting layouts as ways to extend reuse cycles and reduce waste, supporting resource efficiency and circular economy practices in SME construction. Residents’ Perceived Knowledge of Urban Sustainability Challenges in Selected Lagos-Ogun Peripheral Settlements Funmilayo M. Adedire1*, Daniel T. Ogungbemi2, Abiodun A. Okunlola3, Sunday A. Bobadoye4 Department of Architecture, Bowen University, Iwo, Nigeria 1, 2, 3 Department of Architecture, Federal University of Technology, Akure, Nigeria sabobadoye@futa.edu.ng The spontaneous, largely unplanned developments in the periphery of African cities have resulted in unsustainable urban features and developmental challenges. This study assessed residents’ perceived knowledge of urban sustainability challenges in Lagos-Ogun peripheral settlements. A cross-sectional research design was adopted using a multistage sampling technique. Using this method, four settlement clusters located within the Lagos-Ogun periphery, namely Arepo, Magboro, Ibafo, and Mowe, were