Mechanical rail systems offer flexibility, style

Practical option that became popular in the ’80s
By Scott Welch
May 1, 2007

The 1980s gave rise to hundreds of memorable icons including feathered hair, the T-top IROC Camero, pet rocks and Rick Springfield wishing he had “Jessie’s Girl.” Indeed, some of these are better forgotten.

The glass door market also witnessed a new development during the early part of that decade: glass rail systems. The systems are on the top and bottom of glass doors to provide an attachment between the door and the door frame. And like hairstyles, cars and music, they have changed considerably.

At that time, the only method of attaching a door rail to a piece of glass to make a herculite or glass door was to “cement” a solid but heavy extrusion. These types of rails, when cladded in stainless steel, had the end caps welded on and polished for a seamless look and fit. This craftsman method of making doors is both time consuming and expensive but produces a high quality product.
Dorma Glas Door Rail System
Then the press-on rails, or compression fit rails, were introduced and grew in popularity. This economical rail uses screw on end caps and rubber gaskets to secure the glass in place. The system allowed suppliers to create door systems much more quickly to meet the growing demand. Still popular today, compression fit rails use a rubber that is pressurized to hold on sleeker aluminum extrusions.

Both of these rail attachment methods have one potential drawback: they are permanent. Of course, permanence is usually a benefit. You want the rail tightly affixed to the glass. The potential problem arises during installation. If the door-rail unit is even slightly misaligned and hangs irregularly, the contractor has virtually no recourse because the door frame and pivot points are fixed. Correcting the problem requires the installer to send the door back to be refit, which results in lost time and additional cost.

Mechanical rail systems, which have gained popularity in the glass industry within the past five years, overcome this problem. Unlike their predecessors, mechanical rail systems use a screwing mechanism or bolt system that clamps the glass. As the name indicates, this system makes glass doors entirely adjustable, even in the field. The clamp-on rail systems use different types of gaskets to maximize holding power.

The mechanical or clamp-on systems allow for on-site door height adjustment to compensate for irregularities in the door opening height.
The entrance of Quaker, a unit of PepsiCo Beverages & Foods in Chicago
New alignment systems to plumb the door while hanging also are available in many rails. The installer simply adjusts the door by turning screws from the end of the rail to completely square and plumb door relative to the door frame. Additional field adjustments can be made if the door comes out of alignment over time.

Some installers unfamiliar with adjustable rails are concerned about the potential for tampering because of their field-adjusted nature compared to their permanent counterparts. However, installers don’t have to worry; the rails are generally fastened together from alternate sides, making unauthorized removal practically impossible.

In addition, some mechanical rail systems incorporate snap-on covers, which can be attached right before job inspection. Snap-on covers limit the likelihood of aesthetic damage to the metal face during construction, an unavoidable risk with permanently fixed rails.

Also, as the door is used, the glass may chip, crack or break. The adjustable rail system permits on-site glass installation. The rail system is simply removed from the old piece of glass and attached to the new piece in the field, saving time and money.

Adjustable rails are an ideal complement to other glass door hardware that also has become adaptable over the years. For example, locks, headers and hinges can be adjusted on-site using screw mechanisms similar to the adjustable pivot systems. In addition, glass door hardware continues to become slimmer and sleeker to maximize glass area, and rail systems are no exception. A typical system is usually 3 to 4 inches in height. New trimmer small profile rails are less than 2 inches high. For disability access code requirements, rails can range from 6 to 12 inches in height for compliance.

As the adoption of glass doors continues to accelerate in commercial settings such as office buildings, retail storefronts and hospitality applications, specifiers will demand increased flexibility from the hardware. Adjustable rail systems offer just that, especially compared to their fixed-glass options. Old technology will never completely die. But when it comes to door rails, it’s easily trumped by practicality.

Glass door mechanical rail suppliers
C.R. Laurence Co.
Coastal Glass Distributors
Colonial Mirror & Glass
DHD International Inc.
Doralco Inc.
Dorma Glas
Epco Architectural Hardware
Morse Industries Inc.

The author is product marketing manager at Dorma Glas, Millersville, Md., 301/390-1000,