Impact Doors and Multipoint Locks: A South Florida Owner's Guide

What a multipoint lock is

A multipoint lock bolts the door at several points (top, middle and bottom) with one handle or key. You'll usually recognize one because you lift the handle up to engage the locking points, then turn the key or thumb-turn. Many impact-rated French doors, entry doors and some sliders in South Florida use them, because locking at several points helps the door stay tight in its frame under wind load.

Why they get stiff or jam

• The door has shifted. Heat, humidity and settling move the door slightly, so the hooks or bolts no longer line up with their keepers. You'll feel it as a handle that's hard to lift.
• Worn or broken gearbox. The central gearbox inside the door edge wears out, especially if the handle has been forced.
• Corrosion, particularly near the coast.
• Weatherstripping that's thick or new can make the door hard to pull tight enough to engage.

What you can do

• Don't force the handle. Forcing a misaligned multipoint lock is the fastest way to break the gearbox.
• Push or pull the door firmly closed while lifting the handle. If that makes it easy, it's an alignment issue, not a broken lock.
• Lubricate the moving parts along the edge of the door with a light, non-sticky lubricant, and wipe off salt.

Parts must match the door system

Multipoint hardware is usually specific to the door manufacturer and the lock maker, and impact-rated doors are tested as a whole assembly. Swapping in random hardware can change how the door performs, and may affect its rating. Before any replacement:

• Find the door manufacturer's label (often on the edge or the frame) and the lock maker's name on the faceplate along the door edge.
• Measure the faceplate length and the handle spacing.
• Photograph the whole edge of the door, the handle, and the keepers on the frame.

With those, a locksmith or the door manufacturer can source a matching gearbox or lock. Send us the photos, and we'll tell you honestly whether it's a job for us or for the door manufacturer's service department.

Before hurricane season

Check every door that you'd rely on in a storm: does it lock fully, at all points, without force? A multipoint door that only half-engages isn't giving you the protection you paid for. The Florida Division of Emergency Management has the rest of the hurricane-prep checklist.