Reading Number 5, In this Section Ching discusses the different types of building materials that are used and what purpose each of the material fulfills. The materials include Stone, Brick/CMU, Wood, Steel, and Concrete/Reinforced concrete. Each of the building materials Listed has its own select properties: Stone is useful as a load bearing material but has plenty of other uses like making aggerate, decoration purpose and structures like posts or flooring. Bricks/CMU could be used for common building or making masonry walls bricks are listed in 5 different categories each consisting of a different process of manufacturing (soft,sand,water,stiff,dry) and bricks have different ratings to see how durable they are from the elements (SW,MW,NW) Cmu on the other hand is concrete poured into specific shapes but are also used to create walls since these cmu’s are precast they can be made into any shape that will be needed on a building site (come in different weights and exposure ratings to the elements) Wood which come in all shapes, sizes and durability is a strong building element that is very versatile like all these other building elements certain woods are used for different functions based on rating (N,A,B,C,C-Plugged, D) Steel which is common used as wide flange can be used to create beams but is also versatile and lastly concrete and reinforcement, concrete is made by mixing an aggerate with various minerals and water. Once the concrete is mixed it is than poured into casts with steel reinforcement to add structure and reinforcement to the cement.