Excavations

All excavation works must include thorough planning and implementation of necessary temporary supports, such as trench sheets or props, or battering of excavation sides to a safe angle of repose. In wet conditions, a flatter slope is required, while granular soils necessitate a less steep slope before excavation begins. Methods of support are temporary works and must be designed and used in accordance with our Temporary Works policy.

All required equipment and safety measures must be onsite and ready before beginning any excavation work.

Suitable, robust edge protection such as toeboards or projecting trench sheets to prevent materials from falling into excavations must be in place. Head protection must be worn by all personnel.

Plant and vehicles must not be parked close to excavation edges to avoid additional loadings that could cause collapse.

Excavation edges must be protected with substantial barriers, guard rails, toe boards, or trench box extensions to prevent falls into the excavation. Utilise the excavation support system itself to provide adequate protection, ensuring it extends or is properly supported as needed.

Undermining of scaffold footings, buried services, or foundations of nearby structures must be considered. Seek structural engineer advice if necessary.

Additional support for adjacent structures must be determined and implemented as required before starting excavation.

Underground services must be identified, and risks addressed before excavation begins to prevent damage, explosions, or burns. See Underground services section for further information.

Excavation near overhead power lines is to be avoided to prevent contact or arcing. Alternative methods should be considered if excavation is required in such areas.

Excavation supports are to be designed to control groundwater entry. Sumps and pumps should be used to manage water considering the stability impact. Evaluate alternative dewatering methods if appropriate.

Damage to trees and their roots must be avoided to avoid safety hazards. Follow guidance from the National Joint Utilities Group (NJUG) to mitigate risks.

Safe means of access to and from the excavation, such as ladders that are firm, secured, and extend 1m above the landing place must be provided.

Petrol or diesel engines must not be used in excavations without adequate fume ventilation. Avoid placing engines near excavation edges.

A competent person must conduct recorded inspections of the excavation at the start of each shift and after any event affecting stability. Maintain detailed records of inspections, including identified risks, actions taken, and any further actions needed. Reports must include the inspector’s name, location, and date of inspection.

Our Excavations Register can be used for this purpose. If a contractor uses their own register, a copy is to be obtained. Completion of both is not necessary. A record of inspection must be retained for three months.