. . . this pattern finishes the Wall Membrane, and Roof Vaults. It defines the character of their outside surfaces.
Problem:
The main function of a building’s outside wall is to keep weather out. It can only do this if the materials are joined in such a way that they cooperate to make impervious joints.
Background & Research: Not Included on the site—Go read the book!
Solution:
Build up the exterior wall surface with materials that are lapped against the weather: either “internally lapped,” like exterior plaster, or more literally lapped, like shingles and boards and tiles. In either case, choose a material that is easy to repair in little patches, inexpensively, so that little by little, the wall can be maintained in good condition indefinitely.
Usage:
On the hard floor, you can use the same floor as you use on outdoor paths and terraces—hand fired brick and tile—Soft Tile and Brick. On the soft intimate floors, use materials and cloths that are rich in ornament and color—Ornament, Warm Colors . . .
pg. 1093