Building Vibration Monitoring on Construction Sites

Demolition, piling, and excavation transmit vibration through ground to neighbouring buildings. Monitoring against threshold limits protects against damage claims and reassures neighbours during disruptive work.

Standards

• SANS 10328: Code of practice for vibration on construction sites
• SANS 10328: Evaluation of building damage

Damage thresholds (PPV in mm/s)

• Cosmetic damage threshold (typical residential): 15 mm/s
• Heritage / sensitive: 7.5 mm/s
• Hospital theatres / laboratories: 1.0 mm/s

Below these limits, structural damage rarely occurs. Perceptible vibration to occupants begins around 0.3 mm/s.

Common construction sources

• Piling (driven): high vibration, often 5–25 mm/s at nearby buildings
• CFA piling: lower (typically <5 mm/s)
• Hydraulic breakers and rock excavation: high, localised
• Vibratory rolling: moderate, depends on plant

Monitoring equipment

• Tri-axial geophone
• Continuous recording with limits set
• Real-time alerts when thresholds approached
• SMS/email notifications to site manager and engineer

Process

1. Pre-work condition survey of adjoining buildings
2. Install monitoring equipment
3. Set alarm thresholds typically at 50% and 75% of damage limit
4. Real-time monitoring during high-risk activities
5. Daily review of data
6. Pause and review if alarms trigger

Cost

• Monitoring equipment hire: R4,000–R12,000 per week per location
• Schedule of condition surveys: R10,000–R30,000 per neighbour
• Engineer to review data: R3,000–R8,000 per visit

Reporting

Regular reports to neighbours and adjoining owners build trust and reduce claim risk. Document everything.

MCFAR specifies and reviews vibration monitoring on South African projects.

Frequently Asked Questions