Many people already implement ceilings using system formwork, which they usually rent. The ceiling plywood is treated with de-forming oil before concrete is poured to make it easier to de-form, and hired to prevent damage to the plywood. It is for these concrete structures that the special BETONKONTAKT penetrating coating is used. Ordinary plasterers know this and, of course, pay attention to this. Many times this fact is forgotten by those who carry out plastering on their own.
