Water
Mixing water 33 for concrete should be clean and free from injurious amounts of oils, acids, alkalies, salts, organic
matter, or other potentially deleterious substances. When water is used to produce foam, it has to be potable and for best
performance, it should not exceed 25°C. Under no circumstances must the foaming agent be brought in contact with any
oil, fat, chemical or other material that might harm its function (Oil has an influence on the surface-tension of water).
The oil/wax used in moulds will not harm, since the foam by then will embedded in mortar. Water to prepare the mix has
to conform to general requirements for concrete.