In this section of the book Ching speaks about stone, masonry, brick, brick types, brick grades, wood, steel, and concrete. Ching explains that stone is an aggregate or combination of minerals, each of which is composed of inorganic chemical substances. He also says stone should have the following qualities strength, hardness, durability, workability, density, and appearance. Stone may also be classified according to geological origin into types of ingenious rock, metamorphic rock and sedimentary rock. Stone is also similar to modular unit masonry. Masonry refers to building with units of various natural or manufactured products, such as brick, stone, or concrete block. Brick is a mansonry unit of clay formed into a rectangular prism, just like stone there are different types of bricks as well and they are soft mud, sand bricks, water struck brick, stiff mud and dry press. Brick grades designates the Durability of a brick unit when exposed to weathering. In this section Ching explains that wood is strong, durable, light in weight, and easy to work, in addition it offers natural beauty and warmth to sight and touch. Lastly concrete is made by mixing cement and various mineral aggregates with sufficient water to cause the cement to set and bind the entire mass.