Nowadays it is most common to spray on a vapor-permeable membrane or boarding. This mainly applies to attic insulation. The minimum temperature of the substrate in this case is 10ºC. Other materials used in construction, which perform well due to good adhesion with open-cell foam spraying, are: gypsum board (sprayed on partition walls) and concrete (sprayed on ceilings).
IMPORTANT: It is not permissible to apply directly to the tile.