A template is a pattern in the shape of the workpiece, or part of it, used to mark out, transfer or hold a shape or dimension the same way every time. In construction it takes very different forms, but the principle never changes: set it out carefully once, then repeat endlessly without measuring again. That saves time and, more importantly, stops dimensional errors creeping in. The Dutch term is mal.
Types
- Marking template — a plywood or hardboard pattern in the shape of the workpiece, used to draw round. Think of the profile of an arched window head or a repeating corner detail
- Cutting or routing jig — a guide the machine base runs along or over. The best known is the jig for lock mortices and hinge recesses
- Drilling jig — a plate with holes at the right centres, for drilling identical sets of holes
- Formwork mould — the negative shape into which concrete is cast. In precast work this is usually called a mould
- Arch centre — the timber or steel support on which a masonry arch or vault is built until the mortar has gained strength
- Running mould — for running plaster mouldings and cornices: a shaped zinc or steel profile drawn through the wet plaster
- Counter template — the reverse pattern taken from the original; in conservation work the standard way of reproducing an existing profile
Practical rules
- Build the template stiffer than you think you need. One that deflects or wears after twenty uses will pass the error silently into every workpiece
- Give it a datum. Mark top/bottom and left/right clearly so it cannot be used the wrong way round
- Allow for the guide. With a routing jig the cut face sits offset from the template: the cutter radius plus the distance to the guide bush
- With concrete, think about striking. A mould has to come off the hardened piece. Give vertical faces a draft angle and use release agent
- Check the first one. Always make a trial piece before you run the batch
Related terms
- Counter template
- Mould
- Formwork
- Roof setting out
- Profile board
- Precast
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