Exterior Door Construction Materials – Wood vs Fiberglass vs Steel

In the world of entryways, there are three basic material types available for residential exterior doors.
Exterior Wood Door
Wood Door
Exterior Fiberglass Door
Fiberglass Door
Exterior Steel Door
Steel Door


Authentic wood doors use stile and rail construction by joining multiple components to create an overall design that is architecturally correct and features defined details in and around the panels. Wood doors can be stained to enhance their natural beauty. Standard sizes for wood doors typically are 2'-6", 2'-8" and 3'-0" wide by 6'-8", 7'-0" and sometimes 8'-0" high, however they can be customized to fit any size opening. Although wood doors are quite durable, they are not the most energy efficient. As with all exterior products, they require maintenance and should be refinished annually to retain their beauty and avoid issues caused by moisture, especially in unprotected exposures. Standard construction doors can split and crack under high temperatures in addition to parts separating over time. However, when properly cared for, a wood door can last for many years.
Exterior Wood Door Unit
Exterior Wood Door Detail


Fiberglass doors are two large molded skins with a polyurethane foam core between the skins which is a great insulator against heat and cold. The fiberglass sheets, along with the foam core, do not absorb moisture and therefore eliminate the rotting, warping, peeling, and bubbling that can affect other exterior doors. Fiberglass doors mimic the grain of real wood doors and can be painted or stained. They are popular for their high insulation values, low maintenance, and resistance to dents and scratches. Premium fiberglass doors are architecturally correct like wood doors.
Exterior Fiberglass Door Unit
Fiberglass Door Detail


If aesthetics are not a priority and a budget directs the buying process, a steel door is a great alternative. Steel doors can be painted and feature the same polyurethane foam core found in fiberglass doors, therefore offering the same insulating protection against cold and heat. Steel doors will either be hot or cold to the touch depending on exterior weather conditions. Home-to-garage entryways are a prime example of where a steel door is a popular option. Steel doors are economical and offer good insulation, require low maintenance if placed in a fully protected exposure, and won't rot. However, steel doors are highly susceptible to rust and can easily dent.
Steel Door Unit
Steel Door Detail
There are pros and cons to selecting a wood, fiberglass or steel door, however understanding their construction in relation to the concept of exposure will provide you with the knowledge needed to confidently choose the correct door type for your specific exposure.
View our PRODUCT RECOMMENDATION GUIDE to see which materials are best in each exposure type.

There are three material types available for residential exterior doors.  The first one we’re going to talk about is authentic wood.  This is a wood stile and rail door.  It’s made from wood parts and pieces.  The great part about wood doors is that they look so real because they are.  They’re fully customizable.  I can make this door three inches taller, or I can make it three inches wider.  I can make one big panel at the top.  I can do anything I want with it.  People worry about wood doors because of maintenance – wood doors do need to be maintained – all exterior products have some maintenance, but wood doors in particular need that maintenance.  A misconception about wood doors is that wood doors can’t be durable, they can’t last, and that’s not true.  With special construction techniques, wood doors can last for a very long time.

Our next material type is fiberglass.  Fiberglass doors are very popular.  It’s durable because the skins come out of molds and it’s one big continuous sheet – means my parts and pieces can’t separate.  Water can’t get inside there and cause problems.  It’s got a great insulating product.  The downside to fiberglass is I can’t customize it.  I can’t move this panel around, or I can’t necessarily make this door any size.  A misconception about fiberglass is that it really can’t look like a genuine wood door.  Well premium fiberglass products like this come pretty doggone close.

And then finally we’ve got steel.  And steel is popular because of its price.  Downside to steel — it’s the least authentic looking of all the products available, it dents easily, and it can rust.

Exterior Door, Fiberglass Door, Steel Door, Wood Door