Home locks
Door thickness affects more than the screws in a new lock
The assembly, connecting parts and fasteners must suit the door's thickness. A lock that looks correct from the outside may not assemble properly on an unusually thick or thin door. Measure the actual door rather than a decorative trim edge, and compare it with the product's allowed range. Ask whether a manufacturer-approved thick-door kit or a different model is needed.
Measure the door itself
Door thickness concerns the material the lock assembly spans, not the projection of decorative trim or the depth of a raised panel elsewhere. Identify the measurement location in the selected product's instructions. A door that appears ordinary can fall outside a particular hardware kit's range. Establish that fact before purchase rather than discovering during installation that the supplied components cannot assemble as intended.
Check the stated range explicitly
Schlage's Ganton keyed-entry product, for example, specifies a door-thickness range of 1-3/8 to 1-3/4 inches. That example illustrates a bounded compatibility statement, not a rule for all residential hardware. Other products or approved accessory kits may differ. Read the exact model's requirements and ask whether the proposed arrangement uses standard supplied components or a manufacturer-supported option for the actual door.
Avoid improvised component substitutions
Longer screws alone do not establish that every connecting part and internal relationship will suit a thicker door. Likewise, extra spacers should not be assumed an acceptable solution for a thinner one. Have the installer assess the supported assembly as a whole. A lock that can be pulled together physically may still operate poorly or be installed outside the product's intended arrangement.
Account for the surrounding design
A thick decorative entrance may also have unusual trim, panel geometry or nearby hardware that affects clearance. Photograph the full opening and both faces along with the measurement. Keep thickness distinct from backset and the spacing between separate locks. These dimensions answer different questions, and a successful match on one does not remove the need to review the others.
Make the estimate explain the fit solution
Ask the proposal to identify the intended lock model and any approved kit needed for the measured door. If the existing door requires work, understand that scope before ordering a finish or style. Keep the final product and accessory references together after installation. This makes later replacement-part requests more accurate because the next provider can see the actual assembly rather than assume it used a standard package without adaptation.
Before you call
- Measure at the relevant lock area using the product's reference.
- Confirm the exact allowed thickness range and supported accessories.
- Record any approved kit as part of the installed assembly.
Follow-up questions
Will buying longer mounting screws solve every thick-door problem?
No. Other connecting components and product requirements may also be involved. Use the manufacturer's supported arrangement instead of assuming fastener length is the only constraint.
Is a raised decorative panel the right place to measure thickness?
Follow the product's measurement diagram for the lock installation area. A decorative projection may not represent the door dimension the hardware must span.
Official reference
Schlage: Ganton keyed-entry specifications ↗
A named example of backset, thickness and latch options. Its dimensions apply to this product, not all door hardware.
Published by AID Locksmith, owned by Allan, serving Greater Sacramento. General service checklists are editorial guidance; product instructions apply to the named model.