NEBOSH CC Excavation and Demolition Safety

Question 1

Before any excavation work begins on a construction site, what is the essential first step to identify underground hazards?

Accepted Answer

Obtain service plans from utility providers and carry out a CAT and Genny scan of the area

Answer

Start digging carefully with a mechanical excavator

Answer

Ask local residents about any known services

Answer

Check the site boundary for warning signs only

Question 2

What is the primary purpose of trench support (shoring) during excavation work?

Accepted Answer

To prevent the collapse of trench sides, which could bury workers

Answer

To keep the trench dry

Answer

To provide a working platform at the bottom

Answer

To support equipment placed alongside the trench

Question 3

Under what circumstances might battering (sloping the sides) be preferred over vertical shoring for an excavation?

Accepted Answer

When there is sufficient space to slope the sides to a safe angle and the ground conditions are suitable

Answer

When the excavation is in rock only

Answer

When the excavation is deeper than 5 metres

Answer

Battering is never an acceptable method

Question 4

What hazardous atmosphere might accumulate in a deep excavation, and what precautions are required?

Accepted Answer

Carbon dioxide, methane, or hydrogen sulphide can accumulate; gas monitoring and ventilation are required

Answer

Only dust is a concern

Answer

Deep excavations have no atmospheric hazards

Answer

Only radon is a risk

Question 5

A building is to be demolished. Under CDM 2015, what specific document must be prepared before demolition work begins?

Accepted Answer

A detailed demolition method statement prepared by a competent person, included within the construction phase plan

Answer

A verbal agreement between the client and contractor

Answer

A planning permission document only

Answer

A structural warranty certificate

Question 6

During demolition of a pre-2000 building, which hazardous material must be identified and removed before general demolition begins?

Accepted Answer

Asbestos-containing materials (ACMs)

Answer

Lead paint

Answer

Treated timber

Answer

Old electrical wiring