CHS Surface Plus XPO100 Retarder 20LChemical House Surface Plus XPO100 surface retarder, 20 L. Water based surface retarder to slow the concrete curing process, allowing for an exposed aggregate finish. After the completion of all finishing procedures, just before the initial set, apply via low pressure sprayer at a rate of 4 m2 L, neat or diluted 1: 1 with water for up to 20 mm of final exposure. See the below Product Data Sheet for more information. Complies with Green Star Office