I have had many customers ask me, which is better, and what’s really the difference between a steel and fiberglass doors? Let’s start with the difference. The inner frame, which is usually made from wood, and the core, which is usually made from foam, are really quite the same on both steel and fiberglass doors. So the major difference is the outer skin of the door.
A steel door has a layer of steel which makes up the exterior of the door. A fiberglass door has an outer skin made of fiberglass. Steel is made from iron mined from the earth. It is then melted down to remove impurities, which increases the strength of the metal. The process is called smelting.
Fiberglass is actually made from molten glass and various resin materials. Steel doors paint very well and are really quite durable. The steel provides a good measure of security too. Fiberglass doors won’t warp, dent, rust or crack. These doors can be purchased in wood-grain or smooth finish. They can also be stained to look like wood doors. This is a major advantage over steel doors: the beauty of wood, without the maintenance! Usually you can order your door pre-stained to the color of your choice. You normally pay more for a fiberglass door than a steel door. Depending on the look and quality you are looking for, it may be worth the extra costs.
Either of these types of doors have various jamb (exterior frame) options. Jambs are normally made from wood, plastic or a type of fiberglass. Some even have combinations of both. Wood jambs are prone to rotting in the lower portion where they meet the sill. This area tends to collect most of the moisture running down the door. Pick your door jambs according to your needs.
For example, a door under a porch would be protected from the elements. Therefore, a wooden frame would be less likely to rot or need as much maintenance through the years. Choose wisely as the door itself may stand the test of time. However, if the frame fails prematurely you could be searching for replacement options sooner than you would like.
For more information, see: common door installation problems and fixes.