What Is Polystyrene Insulation?

Every home needs to be insulated and there are dozens of products on the market, from polystyrene insulation to using recycled denim. All of these insulation products have their good points as well as their bad. Some of the best insulators are all-natural or made from recycled products, much like polystyrene insulation, which is a green insulation. The following article will explain what polystyrene insulation is, as well as its benefits and disadvantages.

The Basics

Polystyrene insulation is a kind of foam insulation that is used in both residential and commercial settings. Polystyrene insulation is very rigid, unlike its fluffier cousins. As an insulator, it can withstand extremes in temperature and is also a noise reducer. Unlike other insulation materials, it is waterproof and lasts a long time. All of these things make polystyrene insulation stand out as an exceptionally good product.

Expanded Polystyrene Insulation

Expanded polystyrene insulation is less dense and cheaper than the other polystyrene insulation. It is also less effective. Expanded polystyrene insulation is formed out of pockets that are filled with air. It is this design that makes expanded polystyrene insulation less effective.

Extruded Polystyrene Insulation

This is more expensive and more effective than expanded polystyrene insulation. It consists of smaller beads filled with a mixture of air and refrigerant gas. These differences make it a better insulator. The process used to make extruded polystyrene insulation gives it other beneficial properties. It starts its life as solid polystyrene crystals combined with additives, and then it's melted. Pressure and temperature is closely controlled as it's extruded into a viscous fluid that is molded. As it cools, it expands to form foam that can be shaped and cut. The insulation is very smooth and uniform in a way that cannot be duplicated with other insulation products. This process makes it able to be made into panels, blocks you can stack, electrical wiring insulation and a concrete mold.

Pest Control

Some polystyrene insulation manufacturers are adding concrete to the insulation. This small amount of concrete adds slightly to the weight, but makes it impervious to insects and other pests, like termites.

The Cost

The downside of polystyrene insulation is the cost of producing it. The materials that are required to make it are not even remotely cheap. The expensive materials, coupled with the expensive process to manufacture it, add as much as 10 percent to the overall cost to build a home using it. This initial cost, however, may be overlooked by homeowners, contractors and builders due to the savings polystyrene insulation will bring in heating and cooling the home. It will pay for itself over the lifetime of the home several times over.


Every product has disadvantages. It is very costly in the beginning, and it also is flammable. This means it has to be chemically treated, which adds to the overall cost. If exposed to the sun or temperatures over 165-degrees Fahrenheit it can degrade. This is very unlikely, however, as home insulation is not exposed to these conditions.