Standards applicable to cmu contain three classifications of weight, expressed in pounds per cubic foot: Normal Weight, Medium Weight, and Lightweight.
Normal Weight is 125 lbs./cu. ft. and over. Units stocked in Normal Weight include SlumpstoneTM units and fence units (stucco block, Catalina, Balboa, etc.). Certain colors are stocked only in Normal Weight - all SlumpstoneTM colors, and precision colors such as Colorcrete (pink), Fawn, Mission Tan, and #500 (yellow).
Medium Weight is less than 125 to 105 lbs./cu.ft. "Structural" types and sizes are stocked most extensively in Medium Weight. In addition to precision and split face gray, a scored split and standard color are normally available.
Lightweight is less than 105 lbs./cu. ft. Normally stocked in selected sizes in gray.
Of the three weights, Normal Weight is the least expensive and Lightweight is the most expensive. Medium Weight is most popular (and therefore has greatest availability) for structural applications as its moderate weight and cost generally offer the best labor production to material cost ratio. For example weights per units and wall area, please see charts in Technical Articles, Average Weights.