Shown here is a door that is partially insulated. The left side is non-insulated, giving the door no R-value. The right side is vinyl-back insulated (a.k.a polystyrene insulation), giving the door an R-value of 7.4 (average house wall is 13).

R-value measures how well certain building insulation materials can resist heat. The higher the R-value, the greater the insulation performance and sound reduction. We also offer steel-back insulated doors with an R-value of 12.76, a better choice if you would like to heat and cool your garage space.