Garage Door Insulation: Understanding U-Factor & R-Value

The primary entrance to a home is usually through the garage. With living space often above or beside it, it is best to keep the temperature in the garage as controlled as possible. An insulated garage door along with insulated garage walls can significantly help control the temperature of your garage space. The amount of insulation you need in your garage door depends on your region. For example, people who live in extreme hot or cold climates will typically require heavy insulation to help control the temperature within.

U-Factor

The U-factor measures the rate at which heat is transferred through a material, such as a garage door. A lower U-factor indicates better insulation, meaning the sectional door will resist heat flow more effectively.

R-Value

The R-value evaluates the thermal resistance of a sectional door. It represents how well the door can impede the flow of heat. The higher the R-value, the greater the insulation capability of the door. U-factor is not the reciprocal for R-value for residential garage or commercial doors.

U-Factor vs R-Value

The biggest difference between R-value and U-factor ratings is how they are measured. R-value ratings are calculated mathematically by measuring a single section of a garage or commercial sectional door. U-factor ratings, on the other hand, are calculated by measuring the whole door system installed (the entire door, siding, framing, wall, materials used, etc.). This gives a more accurate thermal transference rating and as such, a more accurate picture of the thermal insulation efficiency.

Another reason for the move to U-factor, is that it is difficult to accurately measure the R-value of a section of a panel that is not completely flat (i.e., panels that have grooves or indentations cannot be accurately tested with R-value). U-factor gives a more accurate rating of the entire door, while R-value only measures a section of a single panel.

Garage Door U-Factor and R-Values

Product	Insulation	U-Factor*	R-Value**
Carriage House Garage Door Model 6600	Polyurethane	.05	12.12
Classic Steel Garage Door Model 8300	Polyurethane	.15	12.12
Classic Steel Garage Door Model 8500	Polyurethane	.12	16.22
Vinyl Garage Door Model 8700	Polyurethane	.24	10
Classic Steel Garage Door Model 9100	Polyurethane	.26	9
Classic Steel Garage Door Model 9605	Polyurethane	.26	10
Carriage House Garage Door Model 9405	Polyurethane	.27	10
Designer Steel Garage Door Model 8310	Polyurethane	.15	12.12
Carriage House Garage Door Model 8670	Polyurethane	.16	11
Fiberglass Garage Door Model 8680	Polyurethane	.15	12
Aluminum Glass Garage Door Model 8850	Insulated Glass	.31	1.75
Aluminum Glass Garage Door Model 8850	Low-E Insulated Glass	.28	2.38
Glass Garage Door Model 8800	Insulated Glass	.29	1.75
Glass Garage Door Model 8800	Low-E Insulated Glass	.27	2.38
Builder Door Model 5120	Polyurethane	.27	9
Builder Door Model 5145	Polyurethane	.26	10

*U-factor is independently tested and verified per ANSI/DASMA 105 using solid doors and specific product sizes.
**Wayne Dalton uses a calculated door section R-value for our insulated doors.

Commercial Door U-Factor and R-Values

Product	Insulation	U-Factor*	R-Value**
ThermoMark™ Model 530	Polyurethane	.07	26
ThermoMark™ Model 5150	Polyurethane	.15	12.12
ThermoMark™ Model 5200	Polyurethane	.12	16.22
ThermoMark™ Model 5155	Polyurethane	.24	10
ThermoMark™ Model 5255	Polyurethane	.26	9
Thermospan® Model 125	Polyurethane	.26	10
Thermospan® Model 150	Polyurethane	.27	10
Thermospan® Model 200	Polyurethane	.15	12.12
Thermospan® Model 200-20	Polyurethane	.16	11
Aluminum Door Model 452	Insulated Glass	.28	2.38
Aluminum Door Model 452	Low-E Insulated Glass	.29	1.75
Aluminum Door Model K-AL	Insulated Glass	.27	2.38
Aluminum Door Model K-AL	Low-E Insulated Glass	.27	9

Is U-value the Same as U-factor?

No, U-value is used differently across the building and manufacturing industry, in some instances being introduced as the reciprocal of R-value. Only U-factor ratings are used in the building codes for doors and windows. Therefore, program participants will remove all U-value listings. This will remove any confusion regarding the meaning of U-value for the residential garage and commercial door industry and further emphasize the integrity of U-factor certified ratings.

Wayne Dalton participates in the Door & Access Systems Manufacturers Association (DASMA) Thermal Performance Verification (TPV) Program. The program goes beyond the traditionally published R-value and uses third-party testing to evaluate and certify the thermal transmittance (U-factor) of select residential garage and commercial door manufacturers. Models denoted with the DASMA icon (insert check mark) is indicated as a verified U-factor rating. While we are adding the U-factor ratings to all our applicable models we will keep the R-values listed for these models on our website.

Insulated Garage Doors

The same properties that improve thermal efficiency also give polyurethane insulation excellent acoustic properties. An insulated garage door can significantly reduce the intrusion of street noise into the home – especially important when there are bedrooms or other living areas above or adjacent to the garage. Similarly, an insulated commercial door can also reduce the intrusion of street noise in industrial applications.

Benefits of Insulated Garage Doors

Prevents air leakage
Creates a comfortable environment to work in the garage or business year-round
Better resistance to dents
Reduces street noise from entering
Thermal efficiency - especially when the walls surrounding the door are also insulated

Types of Garage Door Insulation

The type of insulation in your sectional door can also make a difference. Many Wayne Dalton residential garage doors and commercial sectional doors come with one of two types of insulation: polyurethane or polystyrene. Polystyrene insulation is usually used in rigid sheets inserted into sectional door cavities. Polyurethane is a foam that expands and bonds to surfaces when injected into the cavity. Inch for inch, polyurethane insulation is twice as effective as polystyrene.

Polyurethane Foamed-In-Place Insulation

These doors are manufactured with polyurethane foamed-in-place insulation using a patented process. Polyurethane insulation delivers twice the thermal performance of polystyrene insulation of the same thickness! It also adds strength and rigidity to the door panels and helps dampen sound transmission.

If you are interested in upgrading to a garage door with more insulation, Wayne Dalton has one to suit your needs. With a wide range of materials, colors, and styles, you do not have to sacrifice visual appeal for thermal efficiency.

View our product selection, in one of our showrooms, or at your local Wayne Dalton dealer. Our team at Wayne Dalton is here to help you make the next best decision in making sure your home’s garage door is well-insulated.