Where’s the job?

Overview

• Assessing and stabilising residential foundations to prevent subsidence and ensure long-term safety.

• Skill level: 4 / 5 (requires in-depth structural knowledge, excavation expertise and adherence to building codes).

• Typical duration: 1 – 7 days depending on the complexity and underpinning method required.

Safety First

• Ensure temporary supports and shoring are rigorously installed before commencing excavation.

• Always wear PPE such as helmets, gloves, high-visibility vests and safety boots.

• Secure the site to protect residents and workers from falling debris or equipment.

• Avoid undertaking underpinning in adverse weather conditions that compromise structural stability.

Tools & Materials

Step-by-Step

1. Site Assessment – Conduct a detailed survey and structural evaluation to design the underpinning strategy.

2. Preparation – Secure the site, install shoring, and mark excavation boundaries in compliance with regulations.

3. Excavation – Carefully remove soil from under the foundation, maintaining support to prevent collapse.

4. Installation – Place underpinning elements such as mass concrete blocks, mini piles, or beam and base systems into the excavated area.

5. Backfilling – Replace and compact the soil around the new underpinning to secure the structure.

6. Curing & Monitoring – Allow concrete to cure fully and monitor for any further movement in the structure.

7. Final Inspection – Ensure all work complies with building standards and obtain necessary certifications.

Completion Checks

• Structural stability confirmed with no further signs of subsidence.

• Underpinning elements are properly set, cured and compliant with engineering standards.

• Site has been cleared and all temporary supports dismantled safely.

• Final structural inspection verifies adherence to local building regulations.

When to Call a Pro Instead

For complex underpinning challenges – particularly in properties with significant structural movement or historical significance – it is advisable to engage a qualified structural engineer or underpinning specialist to ensure legal compliance and long-term durability.