On this project we used a diluted sodium hypochlorite mix at 1-1.5% to kill off organic growth prior to washing. On projects where we have to remove the joint material we use heated water (up to 200 degrees if needed). On those projects we do not need to pretreat since the heat sterilizes the surface. Otherwise, all of our wash jobs are rinsed thoroughly shortly after pretreatment which leave no SH residue and is safe for pets!
