· by Michael Blair, Nashville's Windows & Doors
Entry doors are compared on appearance and price, and then live for twenty years under whatever sun and humidity the elevation gives them. In Middle Tennessee that difference is substantial.
Steel
Least expensive, structurally strong, and dimensionally stable. It dents rather than cracks and the dents are difficult to repair invisibly.
The weakness is heat and corrosion. A dark steel door in full Nashville afternoon sun gets extremely hot, and any breach in the finish at the bottom edge starts rust.
Fiberglass
The default recommendation for most Middle Tennessee elevations. It does not rot, warp, rust or dent meaningfully, and it handles the humidity swing without moving.
Good ones take a convincing wood grain and can be stained. Cheap ones look like plastic, and the gap between the two is visible from the street.
What are the trade-offs of a wood entry door?
The best appearance and the highest maintenance. In our humidity a wood door moves seasonally, and in direct sun the finish degrades quickly.
On a covered, shaded porch a wood door is entirely reasonable. On an exposed west-facing entry it is a commitment to refinishing every few years.
- Exposed west or south entry: fiberglass
- Covered and shaded porch: wood is viable
- Budget-led or a secondary entry: steel
- Any elevation: check the sweep and threshold quality
What matters as much as the door itself?
The frame and the installation. A good door in a poorly fitted frame leaks air, sticks seasonally and fails to lock properly, and none of that is the door’s fault.
Look at the threshold and the sill pan. Water management at the bottom of a door is what decides whether the frame rots, and it is the detail most often skipped.
FAQ
Steel, Fiberglass or Wood Entry Doors — questions
Is a fiberglass door worth the extra over steel?
On an exposed elevation in Middle Tennessee, generally yes. It does not rust at the bottom edge, does not dent, tolerates heat better and holds a finish longer. On a sheltered secondary entry the argument is weaker and steel is a sensible economy.
Will a dark front door fade in Nashville sun?
Dark colors on any material absorb considerably more heat and fade faster, and on an unshaded west-facing door here that is a real effect. Some manufacturers restrict warranty coverage on dark finishes in full sun, which is worth reading before choosing the color.
Does a new front door improve security?
The slab is rarely the weak point — the frame, the strike plate and the hinges are. A new door installed with a reinforced strike, three-inch screws into the framing and a quality deadbolt is a genuine improvement. A new slab in the old frame with the old strike plate is mostly cosmetic.
Are fiberglass doors strong?
Strong enough for an entry door, and better suited to this climate than steel, since fiberglass does not meaningfully dent, rust, rot or warp. Steel is the stiffer slab, but the slab is rarely where a door gives way; the frame, strike plate, hinge screws and deadbolt decide how well a door resists being forced.