Valley Stone Inc. (VSI) recommends using a mild detergent for cleaning newly constructed Cast Stone. Typically the cleaner used to wash down brick can be used for Cast Stone. The use of raw acid is never recommended on any Cast Stone surface. Always test the cleaner on a small, inconspicuous section of the wall to be cleaned. Testing will help determine the dilution rate that will be required. The higher the dilution with fresh water that is effective, the safer the cast stone will be from damage. Be sure to pre-wet the stone prior to applying the cleaner and then rinse well. Inadequate rinsing leaves residues which may stain the cleaned surface. Where Cast Stone and brick are intermixed, protect cast stone during cleaning of the brick and then clean the cast stone separately.
During construction every effort should be taken to protect the Cast Stone from damage or staining by the use of non-staining tarpaulins and should be stored above ground on pallets or planks. The most common stains during the installation of Cast Stone are dirt and mortar. Excess mortar or dirt should be removed and the stone cleaned with a mild detergent and scrubbed with a brush. Metal or abrasive tools should not be used to for cleaning as it could scar the Cast Stone.