Another type of insulated garage door that is available in our industry is a polyurethane insulated garage door. This is rarely installed in the southern states.

What is a polyurethane insulated garage door? The traditional type of insulation that is in garage doors is the polystyrene insulated type. This type of garage door produces insulating R values of 6.85 to about 11.0. With this type of insulation large sheets of polystrene insulation are cut to the size of the doors and literally are place in the doors with little reinforcement. The steel back or sandwich type garage door, the insulation “floats” between the steel skins.

The polyurethane insulated garage doors provide an insulating R vaule of 12.5 to 17.54. This type of insulation is injected as a liquid between the steel skins that make up the door. As the liguid insulation is in contact with the air, it begins to expand and harden. As it does this, fills in all of the cracks and creavices and becomes semi hardened and very dense. For this reason the Polyurethane insulated doors are only available in the steel back or sandwich door. The insulation will actually adhere to the metal of the door, increasing the strength of the door. The best way I know to make a comparasion is that the polyurethane insulated door is similar to a refrigarator door. The cost of these doors can be substantially more than the traditional insulated door.