Installing a mortice lock might seem like a straightforward DIY task, but the reality is that it requires precision, the right tools and a thorough understanding of lock mechanics. A poorly installed mortice lock can compromise your home's security, void your insurance and cause expensive damage to your door. Here's why professional installation is always the better choice.

The Complexity of Mortice Lock Installation

Installing a mortice lock involves cutting a precise pocket (mortice) into the edge of the door to house the lock body. This requires specialist chisels, a mortice chisel or router, and careful measurement. The pocket must be exactly the right size and depth — too large and the lock will be loose; too small and it won't fit.

The strike plate must also be precisely positioned in the door frame so the bolt engages correctly. If the alignment is even slightly off, the lock won't operate smoothly and may fail to secure the door properly.

Common DIY Mistakes

Incorrect mortice size: Too large weakens the door; too small prevents proper fitting
Misaligned strike plate: Causes the bolt to miss the keep, preventing proper locking
Wrong lock specification: Fitting a 3-lever lock where a 5-lever BS3621 is required
Damaged door: Chiselling too aggressively can split or crack the door
Incorrect backset: Fitting a lock with the wrong backset measurement
Poor finishing: Gaps around the lock body that allow draughts and reduce security

Insurance Implications

Most home insurance policies require locks to be fitted correctly and to meet specific standards. If a lock is poorly installed and a burglar gains entry, your insurer may refuse to pay out on the grounds that the lock wasn't properly fitted. Professional installation provides documentation that the work was carried out correctly by a qualified locksmith.

Keys4U locksmiths can provide a certificate of installation confirming that your locks meet BS3621 standards — invaluable for insurance purposes.

Choosing the Right Lock

A professional locksmith won't just fit the lock you've bought — they'll advise on the best lock for your specific door, usage and security requirements. Factors to consider include:

Door material (timber, UPVC, composite)
Door thickness and condition
Security requirements (residential vs commercial)
Insurance requirements
Budget
Aesthetic preferences

The Cost of Professional Installation

Professional mortice lock installation typically costs between £80 and £150 including the lock. This might seem more expensive than a DIY approach, but consider the cost of getting it wrong — a damaged door, a failed insurance claim, or a security breach could cost far more. Professional installation is an investment in your home's security and your peace of mind.

Keys4U provides professional lock installation across the UK. We supply and fit a wide range of mortice locks, including BS3621 approved models, and provide a 12-month workmanship guarantee on all installations.