Fiberglass Vs. Steel Entry Doors

Hunker may earn compensation through affiliate links in this story.
employee opening a steel door at hotel
Image Credit: Yamini Chao/Digital Vision/Getty Images

In recent years, several new materials have begun to replace the traditional wooden entry door. Steel and fiberglass doors are among the more popular entry door materials today, due to their relative strength and durability, especially when compared to wood. Consumers may find it difficult to choose between these materials because of their similar qualities, though careful consideration will reveal some subtle differences between steel and fiberglass doors.


man using calculator
Image Credit: Brand X Pictures/Stockbyte/Getty Images

When comparing mid to low-grade steel or fiberglass doors, the cost difference between the two is fairly negligible. If one is looking at high-end doors however, fiberglass will almost always cost significantly more than steel. At the other end of the spectrum, both steel and fiberglass doors can be found at relatively low prices, though steel is often the better buy. A cheap steel door may flake or peel, but a low-quality fiberglass door tends to crack or rot.


large fiberglass front door
Image Credit: Images

Most fiberglass doors feature integral color that extends through the thickness of the door. If these doors are scratched or scuffed, the damage is not very noticeable. Steel doors, on the other hand, are painted at the factory or during installation. If steel doors are dented or scratched, the damage is particularly noticeable because the natural metal color will show through. Fiberglass requires little to no maintenance while the most carefully protected steel door will usually require repainting every few years.


small fiberglass door at Spanish villa
Image Credit: Jupiterimages/ Images

One of the most popular types of fiberglass entry doors are those with simulated wood grain. These doors offer the look of wood without the maintenance. While steel doors can also be embossed to resemble wood, they are not nearly as realistic as fiberglass versions. For flush or panel doors however, both steel and fiberglass look very similar, and can be difficult to tell apart from one another at a distance.


fiberglass door at brick home
Image Credit: Jupiterimages/Polka Dot/Getty Images

One of the primary benefits of a fiberglass doors is its long lifespan. Once installed, these doors can be left untended for years, while a steel door may rust or corrode. Untreated rust or corrosion can compromise the lifespan and security of the door. The only situation where steel will likely be more durable than fiberglass is in a very cold setting. At extreme temperatures fiberglass may crack, especially when subject to impacts and abuse.


steel door handle
Image Credit: Jupiterimages/ Images

Steel doors are usually better insulated than fiberglass units. This is due to the construction differences between the two doors. Steel doors are really steel-skinned, with a foam core that helps to keep cold air out of the home. Fiberglass doors are usually solid all the way through, and lack the insulated core found in steel doors. At the same time, steel has a higher level of thermal transfer than fiberglass. This means that steel doors will be very cold in the winter and very hot in the summer. In extreme temperature conditions, this could be an issue worth considering before making a purchase.


Emily Beach

Emily Beach works in the commercial construction industry in Maryland. She received her LEED accreditation from the U.S. Green Building Council in 2008 and is in the process of working towards an Architectural Hardware Consultant certification from the Door and Hardware Institute. She received a bachelor's degree in economics and management from Goucher College in Towson, Maryland.