When Softwash Becomes Hard Wash
In recent months we have seen the promotion of hypochlorite products in the UK and Ireland for cleaning roofs and walls. It takes the form of additives - liquid soap and a citrus terpene or as a ready to use. Sodium hypochlorite is rarely used on the continent: Quaternary ammoniums were introduced 35 years ago for cleaning external hard surfaces, and are the preferred ingredient for many good reasons.