Exterior Fiberglass Doors Everything You Need To Know

As for curb appeal, forget the plastic-looking imposters introduced a couple of decades ago. The best models feature convincingly textured fiberglass “skins,” energy-saving insulation, and a lengthy menu of finish options, as well as molding, glass, and hardware choices to match any house style. “Manufacturers have given the skins real life now,” says Tim Ellenz, president of California Window and Door, a dealer and installer in Palm Desert. Ellenz didn’t even sell fiberglass entry doors 15 years ago; last year, the category accounted for 90 percent of his door business. Consider the aesthetic improvements and a price tag that’s often lower than what you’d pay for a comparable wood door, and today’s fiberglass entry doors become legitimate rivals. Still, finding the best fiberglass entry door that looks and fits right requires a little homework—or just reading on. Shown: Aurora Custom Fiberglass Collection prehung, factory-finished door with hardware, starting at about $5,000; jeld-wen.com

Fiberglass Entry Doors: Important Questions to Ask Before Buying

Slab or prehung?

A slab is just the door; you (or a pro) attach the hinges, drill holes for the hardware, and hang it on an existing jamb. A prehung door comes hinged to a jamb and has a threshold and a weatherstripping system, with the option of a factory-installed lock and latch. You trim it out to suit your house.

What’s it cost?

You’ll pay anywhere from $150 for a smooth-surfaced, paint-ready slab to $7,000 or more for a prehung, realistically textured and factory-stained wood-grained model with lights and molded panels. The sweet spot for a high-quality fiberglass entry door is $1,500 to $2,500. Add on about $400 to $800 to have a pro install it.

How long will it last?

A lifetime warranty is standard; the maker will replace the door if it fails for as long as you own your house. Glass and factory-finish warranties are another story, typically 10 to 20 years and one to three years, respectively.

Where to buy?

Order through big-box stores or, for the largest selection of hardware, finish, and glass options, from an independent specialty window and door supplier.

Fiberglass Door Parts

Think of a sandwich, with glued-on fiberglass skins as the bread and rigid insulating foam as the filling. An interior frame of wood or composite rails and stiles forms the exposed edges.

Where to buy fiberglass door parts

Order through big-box stores or, for the largest selection of hardware, finish, and glass options, from an independent specialty window and door supplier.

Fiberglass Front Doors Pros and Cons

The Pros

It’s stable. Fiberglass doesn’t shrink and swell like wood, so these doors won’t stick in summer or let in drafts in winter. And the molded panels and window grilles won’t require recalling. It’s energy efficient. Thanks to the insulating foam inside, a fiberglass door is typically about R-6, compared with R-2 for wood. Keep in mind, however, that adding windows—even ones with low-e glass—significantly lowers the advantage. It’s low maintenance. The only routine upkeep needed is regular cleaning with a damp cloth. Because fiberglass doesn’t expand and contract, temperature swings don’t degrade the finish. A restorative top coat of clear marine varnish (for a wood-look door) or paint can help prevent fading—which will happen sooner if your door faces the beating sun, has a dark finish, or has no sheltering overhang. Keep that protective coat fresh, says This Old House general contractor Tom Silva, and the finish will look good indefinitely.

Shown: Molded fiberglass panels and simulated divided lights can capture the look of wood French doors. Similar to shown: Prehung, factory-finished European ¾ Light double door, 96 inches tall, about $2,800; pella.com

The Cons

It might not fit. Thinking of installing a fiberglass slab into an opening that’s not square? Make sure in advance that you can make alterations. Some fiberglass doors can’t be trimmed at all. Others can be trimmed only along the top and bottom. Even doors that can be planed on all four sides usually can’t be trimmed by more than half an inch on each edge. It can crack. A fiberglass door won’t dent, but the skin can crack if it takes a hard hit from an errant golf ball or gets banged up during the delivery of your new range. Also, delamination—the skin peeling away from the frame—can occur with doors that have wood stiles and rails, which will absorb water and rot if not kept sealed with paint or varnish. It negates the one-of-a-kind option. Unless you’re willing to shell out $20,000 to $30,000 or more to have a factory create a unique mold for you, you’ll need to pick and choose from all the available standard sizes, options, and extras.

Pro advice: “If the fiberglass skin cracks, you can use Bondo to fill the gap. While the filler is still soft, use a sharp pencil to mimic the door’s graining. Sand the hardened patch lightly and refinish the entire door.” —Tom Silva, TOH General Contractor

Fiberglass vs. Wood Door

It’s hard to argue with the natural beauty, warmth, and authenticity of wood, and you can plane down the door’s edges if the house settles. Today’s laminated veneers and engineered-lumber cores reduce the notorious problems of swelling and sticking. But wood exterior doors remain vulnerable to sun and rain and will rot if you don’t keep up with the caulking and the painting or varnishing.

Fiberglass vs. Steel Doors

They represent the lowest-cost option and still command the greatest market share. But if you want an authentic wood look, metal-skin doors can’t challenge the realism of fiberglass. Plus, steel skins are subject to dents and dings and can be hot or cold to the touch. The best steel products are galvanized, but if the coating wears off, the door can rust. In areas where salt air or frequent rain is an issue, fiberglass has the edge on durability.

Fiberglass Entry Doors: Prices

Good Value

Jeld-Wen Pro Series ($200-$1,500) Putty-like “sheet molding compound” is stamped under high heat and pressure with a steel die to form the fiberglass skins. Stiles are inch-thick laminated veneer lumber (LVL) capped with composite for rot resistance. Rails are full composite.

Better Value

Jeld-Wen Architectural Fiberglass ($1,500-$4,000) Long-strand fiberglass is machine-pressed onto silicone molds cast from real wood doors for realistic graining. Four-inch-thick LVL stiles are capped with a hardwood edge band. Rails are composite.

Best Value

Jeld-Wen Aurora Custom Fiberglass (starting at $4,000) Thick fiberglass sheets are layered by hand onto the silicone molds and vacuum pressed. Four-inch-thick LVL stiles and rails have a hardwood edge band. Finish is hand applied for an authentic look.

Before You Order, Know Your Specs Inside Out

Fiberglass Door Sizes

Companies stock many options within a standard range, typically in 80-, 84-, and 96-inch heights and 2-inch width increments. For a prehung unit, you’ll need the dimensions of the rough opening and the total depth of the wall to determine jamb width. To order a slab, measure the height, width, and thickness of the door it is replacing and choose a stock size to match.

Swing

From the outside, facing an exterior door that swings inward (as most residential doors do): If the hinges are on the right-hand side, it’s a right-handed door, and vice versa.

Safety Codes

For extra security, you can order a prehung fiberglass door with a factory-installed three-point locking system, behind-the-jam metal brackets, and a steel plate in the core. In hurricane zones, make sure your door meets the impact requirements specified by local building codes. Shown: Manufacturers offer a wide variety of clear, textured, leaded, and low-e glass. Similar to shown: Pulse collection prehung and paint-ready door, starting at $580; thermatru.com

Fiberglass Door Designs

Craftsman Style

Look for recessed panels, wood-grain texture, and period details like dentil shelves and patterned and leaded-glass lights. The grain pattern on this door was inspired by Mara, a South American hardwood. Shown: Feather River factory-finished door, about $530 (prehung); homedepot.com

Colonial Style

Molded raised panels suggest the look of wood. But because fiberglass won’t expand or contract, they won’t need recalling. Shown: Six-panel slab door, with wood-grain-texture fiberglass skin and factory-applied paint, from $450; plastproinc.com

Victorian Style

A pronounced oak-grain pattern and tall arched lights give this door a late-19th-century look. Shown: Aurora Custom Fiberglass Collection Model A112 door, starting at $4,800 (prehung); jeld-wen.com

Contemporary Style

Crisp geometric lines give this smooth-skinned door a clean, modern look. Shown: Ari door with low-e glass, from the Pulse collection, from $684 (prehung and paint-ready); thermatru.com

Spanish Mission Style

A dark stain, optional iron strap hinges, and a speakeasy-style window grille give this V-grooved slab its rustic appearance. Shown: Factory-finished door, from about $1,735.

Neoclassical Style

A mahogany-look stained finish and eight molded panels lend an air of formality. Shown: Center Arch door with a factory finish, about $850 (prehung); pella.com

Cottage Style

Tempered glass tops a beadboard panel. Shown: Paint-ready slab, about $610; masonite.com

Tudor Style

This English-inspired arch-top door is also available with strap hinges and nail heads for a Southwestern look. Shown: Classic-Craft Rustic Collection door with factory-applied finish, about $2,400 (prehung); thermatru.com

Finishing Tips

For a painted finish, order a smooth-skin fiberglass door, either factory finished in the color of your choice or primed. If primed, paint it with a high-quality exterior-grade paint, as you would a wood door. For a stained-wood finish, choose a door with the grain texture of the species you want to simulate: oak, fir, mahogany, or alder, for example. Factory finishes are applied and cured in ways that can’t be duplicated at home and give you the toughest, longest-lasting results. For DIY staining, stick with the stain kit provided or designed by the manufacturer for use on the door you order; it contains all the materials you need, and you’ll be sure that the products are compatible with the door.

Custom Fiberglass Doors

Split Doors

Many manufacturers offer the option of turning an entry door with a center rail into a Dutch door. Shown: Two-panel Model A1202 prehung door, with Knotty Alder grain, from the Aurora Custom Fiberglass Collection, starting at $4,100; jeld-wen.com

Curves Ahead

Don’t assume you’re out of luck if the door you want to replace with a fiberglass model veers from the basic rectangle. Shown: Eight-panel radius-top Model A1308 prehung door, with Knotty Alder grain, from the Aurora Custom Fiberglass Collection, starting at $4,500; jeld-wen.com

Ornamental Metalwork

Jazz up a plain entry with decorative hinges, door handles, or nail head trim. The wrought-iron grille design gives this door Garden District style. Shown: Estate Cherry wood grain fiberglass slab door with Sycamore finish, from $1,495.

With Windows

Companies offer transoms, sidelights, and decorative glass to complement your fiberglass door. Shown: Craftsman prehung double door with Homestead windows and transom, about $4,340; pella.com