The reaction of cement – laitance
Laitance – laitance may be one of the manifestations of increased or excessive moisture in tiling; it appears as a whitish coating on the tiling surface. It is the result of water-soluble salts and lime hydrate from cement carried to the surface. Moisture evaporates on the surface thereby creating a lime coating – the laitance. In some products with cement binder, laitance can occur even in the dry state as calcium-carbonate reactions.
Laitance is an aesthetic defect that occurs naturally by maturing of tiles and it has no effect on the quality and technical properties of the tiles.
Laitance will disappear during normal use after rain and snow. In the event that laitance persists, it is recommended to treat the tiles carefully with an agent for cement stains, e.g. Remover of Cement Stain Residues 06.81 made by Den Braven.
Any complaints concerning lime laitance will be assessed according to the scope and severity of the defect.