Polyurethane vs. Polystyrene Garage Door Insulation: Which is Better?

The garage door is the single biggest component of a home’s exterior and, at the same time, the largest moving thing on any given house. It plays an essential role in creating curb appeal, it provides a safe and comfortable place for you to transition from car to house and house to car and it will either cause your energy bills to spike or, if properly insulated, it will help you get them under control. Below we’re going to look at the two most popular types of garage door insulation and see if we can determine whether one is objectively better than the other.

Which Is The Better Type of Garage Door Insulation?

Many models of overhead garage door these days offer fully insulated panels. They play an important role in sealing your home against the elements. Without them the garage is little more than a heat sieve in the wintertime, a kind of funnel drawing heat out of adjoining spaces and venting it to the atmosphere.

Whether you’re about to undergo a new garage door installation, or you have an older door you would like to add insulation to, you have two basic insulation choices: polyurethane or polystyrene. They’re lauded to different degrees for their ability to keep your expensive heated air inside the house where it belongs, but there are important differences between the two. Let’s look at those differences now.

Polyurethane Garage Door Insulation

Polyurethane insulation is sprayed directly into the panels of the garage door, filling the cavity and providing robust insulation. As the polyurethane sets it also adds to the panel’s rigidity which increases the door’s security profile while enhancing the R-value of the door. Polyurethane insulation was first developed 85 years ago and is used today in a variety of commercial and residential applications.

Of the two materials polyurethane is the more expensive and the less flexible. By that, we mean adding it to a door after that door has been installed is essentially a non-starter. It needs to be injected into the panels during the panel manufacturing process. There have been instances of polyurethane being injected into panels on an existing door, but the cost of doing so is likely more than the cost of a new overhead door installation with a pre-insulated door.

Polystyrene Garage Door Insulation

Polystyrene is commonly known as Styrofoam and it is a popular insulation material that is both effective and relatively cheap. Polystyrene is either added to the garage door panels during manufacturing, or sheets of it can be added to the back of those panels long after the door has been installed.

When installed inside garage door panels the polystyrene will not fill out the cavity with the same thoroughness as injected polyurethane. Inevitably there will be pockets of air, typically in the corners of each panel and they can undercut its overall effectiveness. That’s not to say polystyrene is ineffective. It actually works quite well, even when attached to the inside face of garage door panels after the fact. But when compared to polyurethane it will not produce the same impressive R-value.

So Which Type Of Insulation Is Better?

"Better" in this case is a relative term. If you are asking which one does a better job retaining heat, then the answer is polyurethane. However, it's more expensive than polystyrene and you can't really add it after the fact to an existing door. If you are working with a limited budget then polystyrene may be the better choice for you. Likewise, polystyrene is the only one that can be added to the exterior of existing garage door panels to make them more energy-efficient. (Yes, fiberglass batts can also be added to existing doors but this discussion is limited to comparing polyurethane and polystyrene.)

Other Benefits of Garage Door Insulation

• Reduced street noise: Besides helping to get your energy bills under control both polyurethane and polystyrene do a bang-up job dampening noise from the street. If your house is close to the street/road the noise reduction can be significant.
• Reduced door noise: When the panels are filled with either polyurethane or polystyrene the door becomes more rigid and less noisy. The more rigid panels will not shake or vibrate as much as empty panels will as the door opens and closes. The door will also ride more smoothly on the rollers and in the tracks.
• Enhanced safety: Police statistics indicate that 10% of home invasions happen through the garage door. When your garage door panels have been filled with polyurethane or polystyrene insulation they will be much harder to pry open than hollow, uninsulated panels. The insulation will also help prevent dents and dings, corrosion, and weather-related damage.

Get In Touch With Our Broomfield Garage Door Repair Team

By choosing pre-insulated garage doors for your home, or making it a priority to effectively insulate your garage, you can maximize your home's energy efficiency and improve its overall security. As one of the Parker area’s most trusted garage door installation companies we offer a full line of insulated garage doors ready for installation. Or, if you have an older door, we can add after-the-fact insulation to it that will help reduce your energy bills while making your home quieter and safer.

To learn more about insulating your garage door, or to order the installation of a new, fully insulated door, get in touch with the team at A Better Garage Door by calling us at (303) 920-2267.

Want to explore the garage door models offered by our team? Visit our website's page featuring all garage doors available for installation and our online garage door designer.