This paper investigates the effect sulphate exposure has on the thermal conductivity and mechanical strength of low density cement based foams, with and without microfiber reinforcement. This was done by exposing these cement foams to sulfphate over 90 days. The compressive strength and flexural toughness displayed a cyclic rise and fall for the plain sample, and the opposite for the reinforced sample. The thermal conductivity showed an initial rise, but then ...