What is a folding ruler?
A folding ruler is a hinged wooden or plastic measuring stick used by carpenters and bricklayers to measure lengths from a few decimetres up to two metres. In Dutch it is called duimstok and in German Zollstock, both names referring to the inch (duim / Zoll) in which the ruler was originally divided.
Construction
A typical folding ruler consists of:
- Segments — 10 or more sections of 20 cm wood or plastic
- Hinges — brass or steel rivets connecting the segments
- Scale — millimetres, centimetres and often inches as well
- End caps — protective metal plates at both ends
A folded ruler measures 22 cm and extends to 2 metres.
Application
The folding ruler is indispensable for:
- Setting frames and doors — checking diagonals and rebate dimensions
- Measuring ceiling height — stands upright against the wall
- Marking angles — some folding rulers have a protractor at the hinge
- Estimating gradients — a simple triangle reveals the fall
Folding ruler versus tape measure
| Tool | Advantage | Disadvantage |
|---|---|---|
| Folding ruler | Self-supporting, good for heights | Limited length |
| Tape measure | Long distances, compact | Bends during overhead work |
| Laser distance meter | Fast, accurate | Needs batteries, hard to read in sunlight |
Tips for use
- Read from the correct end — some folding rulers carry two scales
- Lay the ruler flat against the workpiece to avoid parallax errors
- Lubricate the hinges regularly with fine oil
- Replace the ruler if a hinge breaks — a wobbly stick produces measurement errors
Related terms
- Inch
- Spirit level
- Plumb bob
- Tape measure
- Setting-out point
Looking for more DIY plans? Check out fredsdiyplans.com.