Writing mortise lock specifications takes care and attention. Small missed details often lead to RFIs, schedule delays, or doors that need rework. Many of these issues start with unclear language or missing prep details.
Mortise locks are not forgiving. They require exact door prep, correct dimensions, and clear function calls. When specs lack this detail, installers face problems in the field. That can slow inspections and raise costs.
Architects should specify mortise locks with the same care used for doors and frames. That includes lock type, function, prep, and finish. It also means planning early for access control when required.
Clear mortise lock specifications help keep projects on track. They also help owners get doors that work as intended on day one.
This article focuses on two commercial mortise lock options from PDQ. The MR Series covers mechanical needs where a mortise lock with key is the right fit. The MR199 Series supports openings that require electrified control.
A mortise lock installs inside a pocket cut into the door edge. The lock body sits within the door, not on the surface. This design supports heavy use and secure latching.
Mortise locks are trusted for strength, longevity, and security. They also support anti-panic, one-motion egress.
Mortise locks are also highly repairable. Institutions routinely stock cams, springs, and parts to keep locks performing like new. With proper maintenance, a quality mortise lock can last 60 years or more.
Specifiers can also choose from a wide range of lever designs, trim configurations, functions, finishes, and keying options.
Common traits include:
Mortise locks are widely used in:
Because the lock is built into the door, proper prep is critical. Architects should specify mortise lock type early, along with door and frame details.
Both mortise and cylindrical locks have a place in commercial construction. Cylindrical locks remain a practical choice for many openings, they install quickly and work well where security demands are moderate.
For high-traffic or high-security openings, mortise locks are often the stronger long-term investment. Advances in door prep machinery have reduced the cost gap between mortise and cylindrical preps. At the same time, ADA lever requirements pushed cylindrical lock prices up as manufacturers added reinforcements to handle the extra leverage. Today, the price difference between the two is often smaller than specifiers expect.
When durability, repairability, and long service life are priorities, mortise locks are worth specifying. PDQ offers both options to fit the needs of any opening.
A mortise lock with key works well when basic security is enough. These locks suit offices, storage rooms, and interior and exterior doors.
Mechanical mortise locks are often used when:
Electrified mortise locks support access control systems. They allow doors to lock or unlock by signal.
Electrified options are often required when:
Architects should specify electrified mortise locks when access control is planned. Coordinate early with security and electrical teams.
Clear mortise lock specifications depend on accurate dimensions and proper door prep. Most field issues trace back to missing or vague details. Architects can avoid rework by calling out exact requirements early.
Mortise locks rely on tight tolerances. Small errors can stop installation. Note that latch and deadbolt centerline dimensions vary from manufacturer to manufacturer, always confirm these align with the strike before specifying or ordering.
Architects should specify:
These details affect fit, security, and code compliance. Leaving them open invites RFIs.
Not all doors arrive ready for mortise locks. Some ship with blank edges. Architects should state when mortise prepped doors are required.
Key risks include:
Retrofits carry higher risk. Re-prep often means pulling doors off schedule.
Coordinate early with door and frame suppliers. Confirm prep matches the lock series.
The PDQ MR Series is designed around common mortise preps. It fits standard commercial door and frame conditions.
This approach helps:
Well-defined mortise lock dimensions help projects move faster and install cleaner.
Start with the opening's needs. Decide if access control is required. Then confirm door prep, function, and code items. Clear mortise lock specifications reduce RFIs and speed submittals.
Best-fit applications
The PDQ MR Series suits high-traffic openings without access control. These doors still need strength and long service life. Common uses include schools, offices, healthcare, and public buildings. Interior and perimeter doors often use a mortise lock with key when access needs are simple.
When to specify
Architects should specify the MR Series when access control is not required, durability is a priority, and standard mortise prepped doors are planned.
Key specification elements
List key elements in the spec so installers have no doubts:
Also include handing, supported door thickness, and any fire rating. These items affect fit, schedule, and inspections.
Certifications and code compliance (MR)
The MR Series carries the following listings and compliance items:
Clear documentation helps installers match hardware to each opening and avoid rework.
Best-fit applications
Some openings need more control than a key. The MR199 supports access control, status monitoring, and remote commands. It fits facilities with strict security policies and managed entry points.
When to specify
Architects should specify the MR199 when readers, keypads, or controllers manage access. It is also a fit when the owner needs audit logs or door status.
Key electrification decisions to coordinate
Electrified hardware adds coordination. Architects should coordinate:
Certifications and code compliance (MR199)
The MR199 includes all MR certifications, plus added listings for electrified use:
Specification advantage
The MR199 uses standard mortise preps, which cuts rework and eases door coordination. Accurate mortise lock dimensions and clear system notes help installs go smoothly. Coordinate early with hardware, door, electrical, and security teams.
Clear mortise lock specifications keep projects on track. They also cut RFIs and change orders. Use the guide below to write clean Division 08 language that installers can follow.
Place all PDQ mortise locks in Division 08, Section 08 71 00 [Door Hardware]. Group items by opening type and function so schedules read clean.
Architects should specify hardware sets that match the door schedule. Keep naming consistent across drawings, specs, and submittals.
List the exact product in both the spec and schedule. Avoid vague terms. Architects should include:
Avoid "or equal" without performance and certification limits. Tie equals to required listings and grades to protect intent.
Call out details that installers and inspectors need. This reduces questions and delays. Include:
Architects should specify mortise prepped doors where needed. Coordinate door and frame preps with the hardware set.
Substitutions can derail the schedule if not managed. Set clear limits. Architects should:
Well-written mortise lock specifications protect the design and budget. Coordinate early with hardware, door, and electrical teams for smoother installs.
Strong mortise lock specifications prevent delays and rework. Use this quick checklist:
Architects should specify clear details in Division 08. Coordinate with door, frame, electrical, and security teams.
Explore the product pages or contact PDQ for assistance.
MR Series: https://www.pdqlocks.com/products/mr-mortise-lock
MR199 Series: https://www.pdqlocks.com/products/mr199-electrified-lockset
Get a clean, confident PDQ mortise lock spec on your next project.