Though conventional aluminum sliders maintain a strong foothold in the market, sliding doors made of wood and other materials have given the genre an entirely new identity. The most popular sliders offer the warmth of wood on the inside and the durable cladding of vinyl on the outside.

Because wood is vulnerable to moisture and sun, it must be given a durable finish. You can buy all-wood sliders that are factory-primed or pre-painted in standard colors; some manufacturers will also custom paint them for a premium.

As alternatives, there are doors made from fiberglass composites that resemble wood but will not crack or warp, and rugged steel sliders, which are usually less expensive. Still other doors are faced on both sides with a vinyl or aluminum skin; a polyurethane foam insulation core fills the shell, offering six times the energy efficiency of wood.

Sliding Door Glazing
Of course, the largest part of a sliding glass door is glass. To make such a door truly energy efficient, high-performance glazing is key. Fortunately, this is standard with most high-quality sliders. You will find dual glazing, or--more typically--double-paned glass with low-emissivity (low-e) coating and, in some cases, argon gas filling.

In addition, some companies offer decorative stained or beveled glass with true brass caming (leading). Like other types of doors and windows, sliders are available with real or false divided lights. Most manufacturers let you specify the glazing you want when you order.

Sizes & Options
Beyond the standard 6-feet, 8-inch height, sliding doors are made 6 feet, 11 inches or 8 feet tall. You can also buy three- or four-door-wide configurations that run up to about 16 feet wide. Sliders are made in single-opening and double-opening styles. To extend your design options, most manufacturers provide matching rectangular and circle-head transom windows intended to fit above doors.

Some companies offer top-mounted insect screens that are easier to use than rolling screens. With these, debris along the bottom glide rail is much less likely to interfere with smooth operation.

Sliding Doors of the Future
Recently, developments have been made thaty break the boundaries of the flat, single-panel residential sliding door. Panda Windows & Doors has created a line of high-end and custom-made sliding doors that even curve around a 90-degree angle. Another new creation is 'lift and slide' technology that, when the door handle is turned 180 degrees, the door actually lifts onto its rollers and moves with ease. When the handle is turned back, the door lowers onto a rubber foot that creates an air- and water-tight seal.