Multipoint Locks: Securing a Door at Several Points

Single-Point vs. Multipoint

A conventional lockset or deadbolt holds the door at one location on the lock edge. Adams Rite contrasts this with multipoint systems, which engage "several locks simultaneously when the door is closed and locked."

The added points are usually at or near the top and bottom of the door, at the lock edge, or both. In commercial three-point systems, the extra points are at the head (top) and sill (bottom).

How a Three-Point Commercial System Works

Schlage's MultiPoint Lock is a published example of the commercial design. Schlage describes it as "a locking system that secures a door at three points: top, bottom and traditional latch location on the side." Its parts and motions are:

• A mortise lock in the door's lock edge, which Schlage says interfaces "with a pair of vertical rods within the door."
• Vertical rods running up and down inside the door to latches at the head and sill.
• One action for all latches: "turning the handle retracts all three latches," and "closing the door automatically engages all three latches."

From the user's side, Schlage says, the lock "functions like a standard door lock." The handle, key, and functions are the same as on a single-point mortise lock. Schlage's data sheet lists familiar mortise functions such as passage, exit, office/entry, classroom, classroom security, and storeroom. See lock functions.

Schlage notes that its high-security version is "an integrated door, frame, and three-point lock solution." The rods come "pre-assembled and factory aligned in door," and the lock, door, frame, and other hardware are ordered separately. In other words, the multipoint lock is designed and ordered as part of the whole opening, not as a stand-alone lock.

Hooks, Bolts, and Shootbolts

Locking points come in different shapes depending on the product. Adams Rite's general description mentions "multiple bolts or hooks." Some systems use latches that engage automatically when the door closes, as in the Schlage design. Others extend bolts when the user operates the handle or key. A HOPPE installation guide from a door supplier, for example, refers to "shootbolts" extended by the handle mechanism.

Because the designs differ, how a given multipoint lock is operated, adjusted, and serviced follows its manufacturer's instructions.

Why Use More Than One Point

Manufacturers give several reasons:

• Resistance to forced entry. Adams Rite says that engaging several points "distributes the force more evenly, making it much harder for intruders to break in," and reduces "the likelihood of the door being pried open or warped." Schlage positions its MultiPoint Lock for "high security applications where a single latch or latch and deadbolt are insufficient."
• Sealing and stability. Adams Rite lists "improved sealing against weather and noise" and greater rigidity of the door.
• Severe weather. Schlage designed its MultiPoint Lock for "areas affected by severe weather, like tornadoes and hurricanes," and offers tornado and hurricane configurations. Schlage states that its tornado solutions "are tested as complete assemblies," including the lock with a specific door.

That last point holds for any multipoint lock: its performance claims belong to the tested assembly, not to the lock alone. A storm or security rating applies to the specific door, frame, and hardware combination that was tested.

Where Multipoint Locks Are Used

Schlage lists schools, assisted living, healthcare, government, and corporate campuses among its MultiPoint Lock applications. Adams Rite notes that multi-point locks "are commonly used in exterior doors." Configurations differ widely by maker, so this page describes the principle rather than any one product.

Multipoint Locks and Other Hardware

• Exit devices. Vertical rod panic hardware also latches at the top and bottom of a door, but it is a push-to-exit device rather than a lockset.
• Handing. Multipoint locks are handed products. Schlage's data sheet notes that handing "must [be specified] on order." See door handing.
• Keying. Schlage says its MultiPoint Lock is compatible with its mortise key systems, including interchangeable cores. See interchangeable core and master keying.
• Strikes. Each locking point needs a matching keeper in the frame. See strike plates.

Related Topics

• Mortise locks: the lock body at the center of many multipoint systems
• Deadbolts: single-point bolt locking
• Strike plates
• Panic hardware: vertical rod exit devices
• Lock functions
• High-security locks
• Euro cylinders

Sources