In order to minimize the geological disaster triggered by expansive soil, and promote environmentally sustainable utilization of industrial-waste, a new composite cementing material was proposed for the expansive soil stabilization based on paper/timber industry waste. In this article, laboratory evaluation is conducted to establish the effect of curing-period for the stabilized expansive soil with newly proposed composite cementing admixture (CCA) and compared it with lignosulphonate (LS) alone, in perspective of various engineering properties, i.e., volume change behaviour, hydraulic-conductivity and strength parameters. Results showed that the curing-period has a notable impact on the performance of CCA. For the soil stabilized with CCA, swelling potential was completely eradicated after seven days of curing; whereas, the strength parameters exhibited improvement till twenty-eight day of curing with some variation in hydraulic-conductivity. Conversely, LS treated expansive soil remained prone to potential swelling after seven days of curing. Further, LS exhibited an insignificant amelioration of hydraulic-conductivity and strength parameters with the curing-period. Based on the test results, it is concluded that the CCA stabilization method is far superior than LS stabilization. Moreover, based on laboratory evaluation, twenty-eight days of time is recognized as the optimum curing-period for CCA treated soil to achieve better engineering properties. © Published under licence by IOP Publishing Ltd.