Upgrading to Continuous Hinges

All doors need some type of hinge mechanism in order to open and close. Most commercial doors are equipped with butt hinges. The door location, size and weight determine the hinge size, base material and number of hinges according to building and local codes and standards. See ANSI/BHMA Standard 156.1, the American National Standard for Butts and Hinges.

Beyond the rules and regulations, the amount of traffic through the door must be considered when installing or retrofitting hinges. Normal wear occurs because of the outward pulling forces (gravity) against the door even when it is closed. Even on a properly installed door, most of the weight and stress is pulling against the top hinge. Over time, a typical three or four butt hinge configuration for a tall, heavy or high traffic door can result in problems closing the door. This usually occurs due to wear on the contacting hinge leafs surfaces. Hinge wear and tear can be accelerated by abuse including opening the door beyond the limit, or when opening or closing using excessive force. “Kickback” can cause the screws in butt hinges to slowly back out. This can result in stripped screws and a sagging door.

Note: Excessive hinge wear is more prevalent on commercial doors equipped with sub standard and non ball bearing butt hinges.

When door closing problems begin to occur, there are two options: replace the worn hinge(s) or replace all of the hinges. An alternative worth considering is upgrading to a continuous hinge. A continuous hinge is a single hinge that runs roughly height of the door. This single length hinge spreads weight of the door further along the hinge’s length instead of concentrating it in three or four locations. With a continuous hinge, the pressure against the door causes it to press against the jamb along the lower portion of the door.

As an additional benefit, a quality continuous hinge requires less force to close the door than the same door equipped with butt hinges. Less force requires less door closer power, beneficial in a building that has closing issues including stack pressure.

Continuous hinges are available in different functions including standard, door edge protection, wide throw and swing clear.

 

Pin and Barrel

Two basic continuous hinge designs are the “pin and barrel” and the geared continuous hinges. The “pin and barrel” continuous hinge is an offshoot of a heavy gauge “piano” hinge. These many-knuckle hinges incorporate a single “pin” running the length. Door “pin and barrel” continuous hinges are normally made of heavy gauge steel, stainless steel and non-ferrous materials. Standard sizes are 79” to 119” or 10’0”. Continuous hinge length should be 1 inch shorter than door size, according to some manufacturers. For example, a 7’0” door should have a hinge length of 83”.

Continuous hinges are available for different amounts of traffic (cycles) and weight doors. ANSI/BHMA A156.26 establishes requirements for architectural continuous hinges. The latest standard is 2012. Check with each manufacturer for the weight and traffic rating for their “pin and barrel” continuous hinges.

An example of a “pin and barrel” continuous hinge is the Markar 300 Series Stainless Steel Hinge that supports door weight up to 600 lbs., having a four-foot maximum door width. The hinge is manufactured from 14 gauge stainless steel, using 2-inch knuckles whose outer diameter is 7/16” and a .187” diameter stainless steel pin (rod). Nylon (medical) bearings at each knuckle separation provide quiet, smooth, self-lubricating operation. Note: The nylon bearings can be optional for some “pin and barrel” continuous hinges.

Additional options for “pin and barrel” continuous hinges can be a 12 gauge hinge, Teflon-coated pin and built-in edge guards.

Most “pin and barrel” continuous hinges are concealed with only the barrel exposed. McKinney offers full and half surface pin & barrel type hinges in steel and stainless steel.

 

Geared

Instead of a pin or knuckles, aluminum geared continuous hinges have teeth (gears) along each leaf’s contacting surface that runs the entire length of the hinge. A cap creates the pivot point for the gears and provides an aesthetic appearance. The two sets of teeth mesh as the hinge opens and closes. Self-lubricating nylon bearings carry the vertical weight of the door, keeping the two leafs in alignment and helping secure the hinge components.

An example of an aluminum geared continuous hinge is the Select Products Model SL11 concealed edge mount continuous hinge available in standard, heavy and lead-lined configurations. The standard duty model supports door weight up to 200 lbs., having a four-foot maximum door width. The heavy duty model supports door weight up to 450 pounds. The SL11 has flush mount alignment stops on each leaf. Self-lubricating polyester thrust bearings ensure smooth operation. On standard duty aluminum hinges, bearings are spaced at 5-1/8” center to center. On heavy duty hinges, bearings are spaced at 2-9/16” center to center.

To permit the hinge length to be modified, the top and bottom Select Hinges nylon bearings are equipped with setscrews. These bearings can be disassembled and repositioned if the hinge length is more than six inches too long.

Mounting configurations for the aluminum geared continuous hinges include concealed (full mortise), face fixed, half surface (mortise), and full surface (mortise). The concealed continuous hinge is preferred when the door is subject to tampering or vandalism. The face fixed hinge is surface-mounted on the door and jamb with the hinge mechanism on the surface of the jamb.

Note: Before purchasing a continuous hinge, remember that some configurations are handed.

Full surface geared aluminum continuous hinges use sheet metal screws to secure the frame leaf. To secure most surface geared hinge door face leafs, use a combination of oval head sheet metal screws and shoulder (mating) screws with barrel nuts (sex bolts). This is to compensate for the thinner gauge of hollow core metal doors. Important: Do not torque down the door mounting fasteners; too much force will crimp the door skin.

Leaf thickness varies depending upon the manufacturer, application, weight and traffic requirements of the aluminum geared continuous hinge. Check with the manufacturer’s web site for the available door size, weight and traffic ratings for your specific applications.

For electronic access controlled doors, there are electronically modified versions of the concealed continuous hinges.

For fire rated openings, the full surface continuous hinges and for some applications, half surface continuous hinges, will probably retrofit. Always ensure the required gap on a fire rated opening will remain after the installation.

Important: When installing onto a fire rated opening, the hinge must have the same fire rating time as required for the opening or the lowest fire rated assembly already installed onto the door.

The PEMKO Double Swing Continuous Geared Hinge allows a door to swing in either direction. In addition to the double swing, this hinge can be ordered for hospital applications where a special flush bolt limits the swing to one direction. Releasing the bolt allows the door to swing in the opposite direction.

Hager Companies offers extra heavy duty aluminum geared continuous hinges. The Roton 1200-600XHD and the 1200-650XHD continuous hinges are designed for doors up to 600 pounds, with the 600XHD for door measuring from 1-3/4” to 2-1/4” thick and model 1200-650XHD for doors 2-3/8” thick or greater. The Roton 1200-600/650XHD hinge thickness is 15/32” and it has 47 bearings spaced at 2.5” on the 119” hinge. Both hinges are designed for flush door having a no inset alignment stop. The extra heavy Roton continuous hinges are available in three standard sizes: 83”, 95” and 119”. Custom lengths are available upon request.

To install a concealed continuous hinge, there must be sufficient gap along the hinge side edge, which is approximately 5/16” to 3/8” without modifying the door edge. The door gap for most fire rated openings is 3/16” or less, too small for a concealed continuous hinge. Important: A fire rated wood door cannot be cut down to accommodate the continuous hinge.

The “pin and barrel” and the aluminum geared continuous hinges are available with up to a three hour fire rating.

A number of Select Hinge concealed aluminum geared continuous hinges have an alignment stop in the leafs to provide basic alignment locating the leafs prior to installation. The alignment stops run the length of the hinges. Different models of geared hinges have alignment stops ranging from equal distance to 1/8” inset.

The gauge of the door and frame can determine the configuration of the continuous hinge. For door in excess of 200 pounds and three feet in width, frame reinforcement is recommended. If the frame gauge is not thick enough to support sufficient number of the mounting screw threads, an alternative is to use Riv-nuts and a full surface continuous hinge. The frame gauge can be determined by removing a butt hinge.

The easiest continuous hinges to install are full surface models. Once the door is located within the opening, there is no need to swing the door in order to install enough of the mounting fasteners to roughly secure the door to the jamb.

Before installing a continuous hinge, use shims to position the door within the opening, having the proper gap along the header, jamb legs and threshold. Start by placing the proper size shims at the top of the door. Use two diagonally cut 2” x 2” shims to raise the door from the bottom.

If installing a full or partial surface aluminum geared continuous hinge, loosen the fasteners securing the cover(s). Do not completely remove these fasteners.

To locate a full surface continuous hinge or a half surface mounted onto the frame, insert a shim between the top of the door and the header at the hinge edge. Draw a thin pencil line down the face of the gear cap from the top about ½”. If the hinge is the same length as the height of the door, it will correctly position the continuous hinge.

Having the shim against the edge of the frame helps to centrally locate the hinge by aligning the edge of the shim with the line drawn onto the front of the gear cap. Make sure the leaf is flush against the jamb face and the other leaf is against the door face with the center of the gear cap positioned over the center of the door gap.

Note: When installing a continuous hinge, the door will settle approximately 1/16”.

A tip from Select Hinges: When installing a full surface geared continuous hinge, if there is an obstruction on the face of the jamb leg, (for example some type of fascia that is too much to trim), the cap does not have to be centered. The geared continuous hinge can be moved over towards the door as long as at least 7/8” on the hinge remains on the frame side.

Mark the locations for the top screw holes and drill the holes in the frame leaf. Install the two frame screws. For the remainder of the frame and door screw holes, use a self-centering drill guide to drill the mounting holes.

Use the correct Phillips Screw tip in your drill/driver to secure the mounting screws. Lower the speed. A piece of electrical tape between the tip and the screw helps prevent slippage that results from deforming the screw head.

Do not install any covers until certain the installation is correct and complete.

For More Information

Here is a partial list of continuous hinge manufacturers and their web sites.

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