Defined

• Polystyrene blocks are blocks made of thermoplastic, which are used as insulation in homes and businesses, but they can also be used for other purposes, such as the material that makes up some bridge rails. Polystyrene is also a material used to create foam board, craft foam, packing foam and other types of foam products, like Styrofoam does. However, polystyrene blocks are much stronger than these other foam products because they can be filled with cement or used as insulation in cement when used in construction jobs.
  
  

Significance

• Polystyrene can be made into small single beads and poured into concrete blocks for insulation purposes (the process is known as MEPS). But these beads as packing for construction cement blocks can move and be blown away if a home surface is penetrated. Polystyrene can also be created by expanding it, a process known as EPS. It is fused together and then used to create blocks, according to the U.S. Department of Energy. And polystyrene can be created through an extrusion process called XPS which involves stamping the molded polystyrene into board shapes.
  
  

Benefits

• According to the U.S. Department of Energy, polystyrene blocks can benefit existing homeowners by limiting their homes' heat loss and keeping them cooler during the summer, resulting in lower energy costs. Another benefit is this materials ability to withstand hurricane-force winds. During Hurricane Katrina, cemented flooring structures remained throughout the state when wooden dwellings and businesses took a beating by Mother Nature and were destroyed. In addition, this particular material does not absorb water, making it an ideal solution against potential flooding.
  
  

R-Value

• In construction projects it is important to know a material's R-value or thermal resistance. The higher the R-value the better the material's ability to insulate a home against the forces that can deplete it of energy or threaten it, such as hot and cold weather and hurricanes. R-value is measured in inches, with polystyrene blocks having a range between R-3.8 to R-5.0 per inch, according to the U.S. Dept. of Energy. But not all polystyrene products boast the R-value rating of polystyrene blocks: beads or loose-fill polystyrene has only a 2.3 R-value. Compare polystyrene products to wood R-values, which range between 1.41 to .71.