Glossary

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IJK

Index disc

Either a red or blue small plastic disc that fits into the top of the capstan head on a rising spindle tap to indicate whether the tap supplies hot or cold water.

Insulation

Any material used to prevent or limit the passage of heat or sound. Also a non-conductive material surrounding electrical wires or cores.

Interceptor chamber

The interceptor chamber is part of a drainage system where the drain from the property connects to the main drain. An interceptor chamber will be covered by a manhole cover.

Jamb

The vertical side section of a door or window frame.

Jointer

A tool used in brick and block work for shaping the pointing.

Joist

Timber or steel beams for supporting floors and ceilings.

Kerf

A groove produced by a saw cut.

Key stone

The central support of a structure, such as in the centre of an arch

Keying

The process of creating a rough surface to provide a better grip for plaster, paint or adhesive.

Knocking block

A small offcut piece of timber used to produce a tight fit between tongue-and-groove boards. The knocking block is held against the edge of the board and tapped a couple of times with a hammer.