Preformed foam is normally used by U.S. and Canadian producers to produce low-density flowable fill, lightweight roof decking and floor underlayments. However, there are also ways to use the material in structural concrete applications. Used as an admixture, the foam improves finishability, pumpability and segregation resistance of concrete. With larger amounts, producers can make block or wall panels and partitions of either precast or cast-in-place concrete. Preformed foam provides low densities, high thermal insulation properties and excellent fire resistance. Foams may vary among suppliers. Their physical, mechanical and chemical properties affect their performance. Keyword: cellular