(C) J Wiley, S Bliss Exterior Doors, Best Practices Guide to Selecting & Installing

  • DOORS, EXTERIOR, Selecting & Installing - CONTENTS: Best Practices guide to selecting & installing exterior residential or light commercial doors. Properties & features of exterior doors including: Exterior Door Materials, Wooden Exterior Doors, Steel Exterior Doors, Fiberglass Exterior Doors and Composite Exterior Doors.
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How to select & install exterior doors:

This article discusses the selection and installation of exterior doors, including the types of doors, how doors are constructed, door energy efficiency, and flashing and sealing doors to avoid air and water leaks.

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DOORS, EXTERIOR, Selecting & Installing

Fiberglass exterior door during installation (C) D Friedman Eric Galow Galow HomesIn this article series we discuss the selection and installation of windows and exterior doors, following best construction and design practices for building lighting and ventilation, with attention to the impact on building heating and cooling costs, indoor air quality, and comfort of occupants.

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We review the proper installation details for windows and doors, and we compare the durability of different window and door materials and types.

Article Contents

Our photograph (above left ) illustrates a fiberglass exterior door during installation. Pre-hung doors make the door installation more rapid and often more accurate, but nevertheless it is important to assure that the door jamb, when set into the opening, is properly secured plumb and square and with proper clearances.

Making the doorway rough opening as square as you can makes for a better time installing the door assembly. The finished, installed door is shown later in this article. Photo courtesy Eric Galow, Galow Homes. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons.

What Exit Doors are Required on Residential buildings?

Pitchfork door lock (C) Daniel FriedmanUsing the Residential Building Code of New York State for an example,

Residential Code of New York State (RCNYS) section R311 requires one side-hinged exit door not less than 3 feet in width and 6 feet 8 inches in height, openable from the inside without the use of a key or special knowledge or effort, that provides direct access to the exterior without requiring travel through the garage.

As described in Best Practices Guide to Residential Construction Chapter 3, BEST PRACTICES GUIDE: WINDOWS & DOORS:

While some entry doors are well-protected from the elements by porches or recessed entries, many face harsh weather exposures in addition to the usual bumps and bruises from children, furniture movers, and others.

In addition, doors must resist warping, shrinking, and swelling across a wide range of temperatures and moisture conditions in order to close tightly and to operate smoothly—all in all, a tall order met with an increasing degree of sophistication by manufacturers.

For new construction, most entry doors are purchased pre hung as an “entry system,” which, in addition to the frame, hardware, weather-seals, and any sidelites, may also include integrated security systems, lighting, and keyless entry systems.

Note: Interior doors are covered under “Interior Finish,” starting on page 186 in the Best Construction text.

Exterior Door Materials

While solid-wood entry doors can last for decades and grace the fronts of many older homes, they are rapidly giving way to a host of hybrid and composite products, some of which are difficult to categorize. While most budget-oriented projects use steel-faced doors, fiberglass and composite doors are the fastest growing market segment, promising greater durability at a price still well below solid wood.

Exterior doors are typically classified by their facing material, but their performance and durability is more a function of their internal construction (Table 3-7).

(C) J Wiley, S Bliss

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Wooden Exterior Doors

Solid core smooth panel exterior door ca 1967 (C) D Friedman Eric GalowTraditional frame-and-panel solid wood doors, once standard fare for residential entries, have become primarily a high-end specialty item.

A few larger exterior door manufacturers, such as Jeld-Wen and Kolbe and Kolbe Millworks, still manufacture stock designs in solid wood, but many who have stayed in the business are niche suppliers of high-end custom doors in an endless variety of wood species, shapes, and styles from Shaker simplicity to 14-foot castle doors (see Window & Door Sources).

Our photo (left) shows a blue-painted solid core exterior door that was installed circa 1967 on a New York home.

On traditional homes a raised panel solid wood exterior door has been used for more than 100 years. The door needs to be kept painted and sealed or protected from the weather by an entrance roof.

To improve strength and stability in wood doors, Kolbe and Kolbe uses laminated-veneer lumber (LVL) for locking rails, and custom door makers Lamson-Taylor and Simpson build up their rails, stiles, and panels from two or more layers of wood.

Lamson-Taylor laminates foam insulation between two solid wood faces to create a unique insulated wood door that the company says is immune to problems with temperature and humidity differences across the door.

To keep costs down and improve stability, many manufacturers offer simulated panel doors with a real wood veneer over an engineered wood core.

These are sturdy and offer good value, but the veneered face is more vulnerable to damage than a solid wood model.

If well maintained and periodically repainted or stained, a high-quality wood door can last indefinitely. However, they are best suited to temperate climates and should be protected from direct weather exposure with a suitable overhang or inset.

Steel Exterior Doors

Steel retrofit exterior door (C) Daniel Friedman

A premium residential steel door has a 24-gauge or heavier galvanized steel skin over a wood or steel frame filled with foam insulation. This creates an extremely strong and durable product with an effective insulation rating of about R-8 for polyurethane insulation versus about R-5 for polystyrene.

Our photo (left) shows a steel exterior door retrofit to a 1920's home in Poughkeepsie, NY, adding security and weather-resistance to the structure.

Most steel and other hollow-core doors contain a wood or composite lock-block for mounting the lockset, and may use wood, engineered lumber, or steel for the stiles and rails.

Bottom rails, which get the greatest exposure to water, are sometimes made of waterproof composites.

(C) J Wiley, S Bliss

Steel is the strongest edge material but requires a thermal break to prevent condensation around the door’s interior perimeter.

Wood forms a natural thermal break, but it is prone to decay along the door bottom if not kept well painted (Figure 3-23).

Here is a closeup photo of a rotted bottom rail in a vinyl-covered storm door -DF.

Rusted steel exterior door (C) Daniel Friedman

Watch out: Our photo (left) shows a rust-damaged exterior door that was exposed to weather and not maintained. The door frame and trim at this opening were also rotted. Unused, the building owner didn't notice this deterioration until the door, jamb, and trim all needed to be replaced.

Here is a closeup photo of the rusted door bottom.

Most steel doors come embossed with a wood-grain pattern and preprimed with a baked-on polyester finish, although smooth metal finishes are also available.

For better protection, some manufacturers apply a vinyl coating with wood grain, which can be stained with a high solids stain. The vinyl is fairly durable, but deep scratches are difficult to conceal. For a more realistic wood look, some manufacturers apply a stainable wood-fiber finish. Follow manufacturers’ recommendations regarding prep work and finishing.

In general, premium steel doors are very strong and durable, although they require regular painting and over time will likely acquire a dent or two. Rust is generally not a problem with galvanized or stainless-steel facings, but condensation can damage finishes on doors without thermal breaks.




Fiberglass Exterior Doors

Fiberglass exterior door (C) D Friedman Eric Galow

Fiberglass doors, first introduced by Therma-Tru in the early 1980s, are built internally the same as a steel door with internal wood rails and stiles and a rigid foam core.

The fiberglass facing is typically embossed with a stainable wood grain, but is also available with a smooth finish that when painted is hard to distinguish from a painted wood door. Fiberglass doors generally price midway between a steel and wood door and carry long-term warranties.

Fiberglass, while not as strong as steel, is very durable, stable, and energy-efficient. It will not warp, crack, or swell like wood and will not dent like steel, making it a good choice in harsh weather exposures.

While fiberglass can be gouged or cracked if hit hard enough, repairs are no more difficult than for steel doors. Scratches, however, are difficult to sand out without destroying the wood-grain pattern on embossed panels.

Our fiberglass exterior door photo (left) is installed on a home in New York. We plan to construct an entry roof to further protect the door from the weather. Photo courtesy Eric Galow, Galow Homes.

Composite Exterior Doors

A new breed of engineered wood doors are built of a variety of engineered wood materials, including laminated-veneer lumber (LVL), exterior-grade medium-density-fiberboard (MDF), and exterior-grade particleboard. Some are built with an engineered-wood skin over a foam or particleboard core, while others are milled from a single slab of MDF. Most come with either smooth or embossed wood-grain finishes ready to paint or stain.

Composite doors tend to price between steel and fiberglass and carry warranties up to 10 years. While many wood composites have established a good track record in exterior use, others, such as hardboard, have had problems with swelling and delamination if exposed to the weather and not protected by a good coat of paint.

As with real wood, it would be prudent to use these products in a sheltered entryway and keep them well painted. Until long term durability has been established, their use remains an open question.

Manufacturers of Windows & Doors

Windows and Patio Doors

Door Manufacturers & Products Guide

Industry Associations for Windows & Doors

-- Portions of this article were adapted and paraphrased, edited, and supplemented, with permission from Best Practices Guide to Residential Construction.


Continue reading at DOOR FLASHING DETAILS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


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