Even in Santa Barbara, where it rarely freezes, colorful beautiful wall tiles in an exterior area  subject to intense heat will delaminate, ruining your mosaic.

The Italian term “andamento” (plural is andamenti) refers to the flow of the mosaic pieces, called “tesserae.” That is, the individual pieces of a mosaic follow the form of the image that is described. The Romans and Greeks invented this way of making images visually coherent in mosaics.