From Waste to use: plywood usage and wastage in slab and beam construction

Abstract

Plywood formwork is widely used in reinforced concrete slabs and beams construction due to its flexibility, availability, and ability to produce smooth finishes. Nonetheless, a considerable amount of plywood is usually wasted on the construction sites due to inefficient operations such as cutting, recurring reuses, improper stripping, and improper handling. This results in increased material consumption, higher project costs, and greater construction waste, particularly in large-scale projects. Despite its widespread application, limited research has examined plywood usage and wastage in real construction settings, especially in developing countries such as Sri Lanka. This paper presents plywood usage practices and associated wastage in slab and beam formwork in projects undertaken by major contractors in Sri Lanka. A case study strategy was adopted, involving five case studies of large-scale construction projects. Data were collected through semi-structured interviews, site observations, and document reviews, and analysed using cross-case analysis. The results show that plywood is primarily used for slab soffits and beam sides formwork, with an average reuse life of three to five cycles, depending on material quality, level of supervision, and labour handling practices. Offcuts generated during the cutting processes were identified as the major source of plywood waste, while damaged sheets mainly occur during stripping and repeated use. The paper explains the improved supervision, the planning of cutting layout, and better material handling practices to enhance reuse cycles and minimise waste. These findings provide practical guidance for contractors and policymakers to improve resource efficiency and promote more sustainable construction practices in large-scale projects.