Groundworker Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Groundworker interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 25, each with a note on what the interviewer is really after.

Eight Groundworker interview questions, and what the interviewer is thinking

1. What is the purpose of a CAT scan and genny, and how do you use them before breaking ground?

Why they ask: Checks that you can locate buried services safely before digging.

2. How do you support an excavation, and what checks are needed before anyone goes into a trench?

Why they ask: Tests knowledge of trench safety, a leading cause of groundworks fatalities.

3. How do you lay and compact a sub-base to Type 1 specification, and how do you know it is right?

Why they ask: Checks practical knowledge of foundation and road base preparation.

4. How do you set out and install a drainage run, including falls and bedding?

Why they ask: Drainage installation is a core groundworker task and gets tested.

5. What types of concrete mix and consistency would you expect on a groundworks job, and how do you place it?

Why they ask: Checks you understand concrete grades and basic placement.

6. You start digging and hit what looks like a live cable. What do you do?

Why they ask: Tests emergency response to a service strike.

7. Tell me about a time you worked on a groundworks job where you had to adapt to difficult ground conditions.

Why they ask: Seeks real practical experience with ground problems.

8. What does a typical day as a groundworker involve?

Why they ask: Checks realistic understanding of the job.

A sample answer to question 1

What is the purpose of a CAT scan and genny, and how do you use them before breaking ground?

A cable avoidance tool detects the electromagnetic signal from live cables and metallic pipes, and the genny sends a signal along a pipe or cable so it can be traced more accurately. Before breaking ground I check the service drawings and permit to dig, then scan in a grid pattern, in both directions, because a single sweep can miss a service. I mark what I find with spray paint or pegs, then use hand-dug trial holes with insulated tools to confirm depth and position. I follow HSG47, so I never assume the scan is conclusive. Non-metallic services like plastic water pipes may not show up, so drawings and caution still matter. I scan again if the dig route changes.

Common mistake to avoid: Relying on the scan alone; ignoring plastic or unrecorded services

Want the rest?

Full model answers, key points and common mistakes for all 25 questions are on the Groundworker interview questions page. The first five are free, no sign-up needed.