Groundworkers A–Z dictionary
UK trade reference · plain English
What is below the finished surface determines the success of foundations, slabs and drainage. Ground conditions, trees, buried services, water and neighbouring structures all influence design and construction. There is no universal safe excavation depth or standard foundation detail for every extension. Agree inspection points and record what is built before it is concealed. Excavation safety and utility avoidance need planning before the machine arrives.
This A–Z combines useful technical vocabulary with links to full references where the article meets our depth and sourcing checks. An unlinked definition is intentionally kept here rather than turned into a shallow standalone page. Read a quotation against its actual scope: a familiar word is not a complete specification.
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C
- CAT scan
- On site, often shorthand for using a cable avoidance tool, not a medical scan. Locating services needs a complete safe system.
D
- Dig out
- Excavate or remove material. Depth, extent, disposal and service precautions need to be specified.
F
- Formation
- The prepared ground level on which the next specified construction layer is placed. Weak or disturbed areas need assessment.
G
- Genny
- A generator in some site conversations, but a signal generator in cable-avoidance work. These are not interchangeable.
- Getting into groundworks
- Groundworks prepares sites and forms below-ground or external construction such as foundations, drainage, concrete and kerbs. It is more than digging: accurate levels, services awareness, safe excavation and following the engineered design are fundamental. Plant operation needs separate competence and authorisation rather than following automatically from the groundworker job title.
- Getting into steel fixing
- Steel fixing positions and secures reinforcement for specified concrete construction. Reading drawings, maintaining the designed arrangement and coordinating inspection matter before concrete conceals the work. It is not the same occupation as structural steel erection, and a site card alone does not establish competence for every reinforcement task.
- Ground bearing slab
- A slab supported by suitable ground or prepared fill. It differs structurally from a suspended floor.
- Ground investigation
- Ground investigation collects and interprets information about the ground for a defined project. It can address bearing conditions, groundwater, contamination and other constraints, but those questions need a planned scope. A trial hole, a soil sample and a complete geotechnical or environmental assessment are not interchangeable services.
- Groundie
- An informal name for a groundworker; also used in arboriculture for someone working on the ground.
H
- Heave
- Upward ground movement which can affect structures. Ground conditions and changing moisture may influence the risk.
M
- Made ground
- Ground containing placed or disturbed material. Its variable composition and history can affect design and contamination assessment.
P
- Pile
- A foundation element transferring loads to suitable support through an engineered arrangement. Type and capacity depend on ground and structure.
S
- Service tracing
- Investigation of buried utilities as part of planning safe work. A detector scan alone does not guarantee clear ground.
- Settlement
- Downward movement of ground or construction. Its cause and significance require context rather than an instant diagnosis from one crack.
- Spoil
- Material excavated from the ground. It is not automatically clean or suitable for reuse.
- Strip foundation
- A strip foundation is a continuous band of concrete supporting a load-bearing wall. It spreads the wall’s load onto suitable ground. Its width, thickness, depth and reinforcement, where needed, depend on the building and site. A trench dug to a familiar depth is not enough to establish a safe foundation design.
T
- Temporary support
- An arrangement maintaining excavation or structural stability during work. It must be planned for the actual conditions.
- Type 1 sub-base
- Type 1 is a specified grading of granular material used for sub-base construction. It is intended to form a compacted supporting layer, not a decorative surface or a universal drainage material.
W
- Whacker
- Informal name for a plate compactor, derived from a well-known equipment name. Confirm the actual machine needed.
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Sources and further reading
Linked article sources support the technical background; informal usage is editorial and varies by region. Full specification and legal requirements must be checked in the original.
Sources checked: 8 November 2026. General reference, not instructions for safety-critical DIY. National regulations and current standards must be checked for the project.
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