During Toronto’s large-scale urban renewal (1950–70s) and economic-led redevelopment (1980s–90s), significant swathes of the city were demolished, making way for modernist superblock housing, new institutions, and civic landmarks, producing tons of demolition material. As these demolition materials were deposited along the shore of Lake Ontario, they solved a material disposal problem, but they also constructed new real estate and landscapes of recreation and leisure. This paper explores relationships between demolition and construction activities in post-war Toronto in three registers: 1) as cyclical urban processes of development and destruction; 2) as the demolition industry shifts from salvage to wreckage model; and 3) as shifting perceptions and composition of shoreline-bound demolition material shaped the Lake Ontario Shoreline. Demolition is an easily overlooked, yet intrinsic, dimension of construction history; its study offers windows into the entanglements between processes of urbanization, construction culture, and cycles of materiality.