Living in the Las Vegas area your door will be subjected to extreme temperatures, hot & cold, consider a well-insulated door to ensure your maximum comfort. The higher a door’s R-value, the greater its insulating properties. Insulated doors offer R-values up to 17.5. This is made possible by a continuous layer of foamed-in-place polyurethane insulation sandwiched between two layers of rust- and corrosion-resistant steel. These doors also feature between-section seals that provide added resistance to air infiltration, as well as bulb-type bottom seals that guard against wind and rain.