Smart Locks for Thick, Narrow, or Weather-Exposed Doors

A thick door, crowded trim, and outdoor exposure are different fit questions. A kit can address a stated thickness range while leaving clearance, strike alignment, material, and normal operation unresolved.

Keep the checks separate

• Thickness: Measure the door leaf where the lock mounts. Compare it with the exact model’s standard range and any named kit range.
• Clearance: Check the inside and outside bodies against handles, trim, glass, a storm door, and nearby hardware.
• Exposure: Read whether the stated temperature or weather value applies to the exterior assembly, the whole lock, or only a component. A rating does not predict operation on every installed door.
• Kit scope: Match the accessory to the exact model and the maker’s current instructions. A kit addresses only its stated condition.

Schlage’s published BE489 thickness guidance differs by document. Its existing-hole preparation PDF (revision 10/18-a) lists standard preparation from 1-3/8 to 1-3/4 inches and a thick-door kit from 1-7/8 to 2-1/4 inches. A Schlage Residential installation support article updated August 19, 2025 instead lists a 1-7/8 to 2-1/2 inch kit range for both BE489 and BE499. The availability table updated September 9, 2026 names kit B489-106 for BE489 and BE499 at 1.75 to 2.5 inches.

For a BE489 door thicker than 2-1/4 and up to 2-1/2 inches, the newer support guidance extends beyond the older BE489 preparation PDF. The newer sources also differ on the lower kit boundary: the availability table starts at 1.75 inches, while the installation article starts at 1-7/8; the older PDF does not state a kit range between its 1-3/4 inch standard limit and 1-7/8 inches. Confirm the exact kit and current BE489 instructions with Schlage when your measurement falls in either disputed or unstated interval. A listed thickness range still does not establish clearance, strike alignment, material suitability, or normal operation.

For a different path, Lockly describes its Lyro Lasta as a manually turned thumbturn rather than a motorized deadbolt. The product page lists an optional extension-kit path for doors up to 4-3/4 inches. That wider stated range does not establish the fasteners, nearby clearance, market package, or fit of another Lockly model. Decide separately whether manual turning meets the intended use.

Cold or wet conditions also need exact-model evidence. Manufacturer operating limits are not comparative field tests across doors, batteries, frames, and climates. If the source is incomplete or conflicts with another current instruction, keep the result conditional and ask the manufacturer or a qualified installer.

Start with the preparation worksheet and use the USA–Canada check when the product or support path crosses a border.