Abstract: A method for the surface treatment of a substrate, for example concrete roof tiles, comprising spreading a layer of water-containing hardenable paste containing binder and other particles, for example a cement based slurry, covering the paste layer with (a) a flexible membrane or (b) a plate or (c) first a flexible membrane then superimposed thereon a plate, the plate or membrane having an upper-surface and a smooth under-surface, optionally vibrating the membrane-covered or plate-covered area of the paste layer, such that vibration is transmitted through the membrane or plate, to the paste layer, and either removing the membrane, plate or plate and membrane then hardening the paste layer on the substrate, or at least partially hardening the paste layer on the substrate with the membrane, plate or plate and membrane in place.

Abstract: A method for the surface treatment of clay, ceramic or cementitious articles, especially roofing tiles, comprising providing a hardenable, water-containing mass (1) shaped in the form of the article, then covering an exposed surface area of the article with a flexible membrane (3), such as a plastics film, having an upper-surface and a smooth under-surface, such that the latter is in intimate contact with and conforms to the contours of that surface area of the article, thereby providing a membrane-covered area of the article, vibrating the membrane-covered area of the article, for example via a vibrator head (6) applied to a rigid plate (5) overlaid on the membrane, such that vibration is transmitted through the membrane, to the surface of the article, and either removing the membrane then hardening the article, or at least partially hardening the article with the membrane in place.