Styrofoam is the generic term for polystyrene insulation, a type of insulation commonly found in home construction which has some pros and cons. The lightweight material is less irritating to install than fiberglass insulation and is easily cut to fit into walls and ceilings. The insulating factor of polystyrene insulation is far less than a comparable fiberglass bat. One pro that the polystyrene insulation offers is that it is relatively inexpensive. Perhaps the greatest con with this material is its inability to absorb moisture.

Insulation does two things when properly installed: it retains heat in the winter as well as reflects heat during the summer. While fiberglass insulation is most commonly known by the average homeowner, polystyrene insulation is a viable option for most insulating needs. It does, however, have some drawbacks and benefits that should be investigated prior to its installation. The ease of installation and lack of skin irritation is one benefit of installing the polystyrene insulation. Most commonly known as pink or blue board Styrofoam™, polystyrene insulation comes in large square sheets that are scored with a knife for easy separation in intervals that match most common stud spacings.

The easy separating construction is a pro responsible for time savings in many installations. The board-like configuration of the Styrofoam™ prevents sagging and falling of the insulation over time. This prevents hot and cold spots in any given exterior wall. The most problematic trait of the Styrofoam™ board is in its inability to wick moisture out of the structure. The smooth finish on the foam board is resistant to water; therefore, any moisture trapped in the wall will remain in the wall without a way to be vented away.

Another con with the polystyrene insulation is its incompatibility with most electrical wiring. The protective plastic coating used on most common electrical wiring will erode prematurely if it contacts the foam insulation. This can lead to electric shock as well as fire that could potentially injure or kill occupants of the structure and could result in loss of the structure itself. Some manufacturers offer wiring with a special purple coating that will not be damaged by the insulation. This can, however, negate any cost savings from using the polystyrene insulation over the fiberglass type.

Another con in using this type of foam insulation lies in the relatively low insulating properties of the foam when compared to fiberglass bat-type insulation. The polystyrene insulation must be applied in several layers in order to achieve the same rating as a single bat of the fiberglass mat. When installed between a structure's roof rafters, the foam adds a layer of insulation that is energy-saving and efficient.