Lock Shop Direct measurement guide
How to Measure Garage and Roller Shutter Locks
Use this guide to identify and measure replacement locks and handles for up-and-over, sectional, side-hinged garage doors and roller shutters.
Important: Identify the door type and complete operating mechanism before removing anything. Garage-door springs, cables and powered operators must not be disturbed during a simple lock measurement.
1. Identify the garage or shutter type
Different door constructions use very different locks and operating parts. Identify whether the opening is an up-and-over canopy door, retractable door, sectional door, side-hinged door or roller shutter.
Up-and-over canopy
Door tilts out and up with tracks or pivot arms. Central handles often operate cables or rods.
Up-and-over retractable
Door retracts fully into horizontal tracks. Check lock and handle clearance through travel.
Sectional door
Hinged horizontal panels travel in tracks. Use hardware designed for the panel system.
Side-hinged doors
Measure each leaf, meeting stile, rebate and bolts in a similar way to a pair of doors.
Roller shutter
Interlocking curtain rolls above the opening. Locks may be central, rail-mounted, bullet or ground locks.
Powered door
Do not modify locking or safety systems without checking the manufacturer and competent installer.
2. Measure an up-and-over garage lock
Where a central handle operates cables, rods or locking bars, record the complete mechanism rather than the handle alone.
Measure the handle, lock body, spindle and linkage arrangement.
| What to check |
How to measure or identify it |
Record |
| Door thickness |
At the lock and handle position. |
_____ mm |
| Handle fixing centres |
Centre-to-centre spacing of handle or escutcheon fixings. |
_____ mm |
| Spindle |
Profile, width, length and how it connects to the lock. |
________ |
| Lock body |
Width, height, depth and fixing centres. |
_____ × _____ × _____ mm |
| Cable/rod travel |
Connection type, length and direction of movement. |
________ |
| Locking points |
Number and position of side, top or bottom latches. |
________ |
3. Identify the handle and spindle
Garage handles can use square, diamond, rectangular, splined or manufacturer-specific spindles. Check the cross-section and orientation as well as the length.
Compare spindle profile, handle shape and fixing arrangement before ordering.
- Handle shape and rotation.
- Spindle profile and dimensions.
- Usable spindle length through the door.
- Escutcheon or backplate dimensions.
- Inside release and emergency override.
- Key type, code and keyed-alike requirement.
4. Measure a roller-shutter lock
Roller-shutter locks may be fitted in the bottom rail, central slat, guide rail or side frame. Record the shutter profile and available clearance.
Measure the case, faceplate, cylinder and bolt or bar arrangement.
| What to check |
How to measure or identify it |
Record |
| Lock case |
Width, height and depth of the body. |
_____ × _____ × _____ mm |
| Faceplate |
Length, width and fixing centres. |
_____ × _____ mm |
| Cylinder/keyway |
Type, projection and operating direction. |
________ |
| Bolt or bar |
Width, thickness, throw and direction. |
________ |
| Shutter/rail profile |
Channel dimensions and fixing material. |
________ |
| Clearance |
Space behind and beside the curtain during movement. |
_____ mm |
5. Safety before removal or modification
Garage doors can be dangerous: Springs, cables, counterbalances and powered operators can store significant energy. Do not loosen or alter them as part of a lock measurement. Isolate powered equipment and use a competent garage-door engineer where the work affects the operating or safety system.
- Support and secure the door before removing a central lock or linkage.
- Do not drill where springs, cables, electrical wiring or moving parts may be hidden.
- Check that added locks cannot be engaged while an automatic operator is used, unless designed for that system.
- Test manual release and emergency access after fitting.
Still not sure which product you need?
Send our team clear photographs and your measurements before ordering. Please include:
- A full photograph of the door inside and outside.
- Close-ups of the lock, handle, spindle, cables or rods.
- Door type, material and thickness.
- Lock case, handle fixing and spindle measurements.
- For shutters, the lock case, bolt and rail or curtain profile.
This guide is intended to help identify and measure replacement hardware. Product designs, terminology and handing conventions can vary by manufacturer. Always compare the complete product specification and fitting instructions. Where a door or fitting forms part of a fire escape, fire door, powered system or other safety-critical installation, obtain advice from a competent person before ordering or altering the hardware.