July 2025 Newsletter: How to Conduct a Basic Lightning Audit (and When to Call Bolt Guard)
South Africa has one of the highest lightning strike rates in the world—with Gauteng, Mpumalanga, and KwaZulu-Natal being among the most storm-prone regions. Every year, homes, factories, and farms suffer millions of rands in losses due to lightning damage.
But most of this damage is preventable.
A lightning protection system isn’t just for power stations or corporate headquarters—every building, home, and business needs protection. In this guide, we’ll walk you through a basic lightning protection self-audit and help you understand exactly when to call in the professionals at Bolt Guard.
What Is a Lightning Protection Audit?
A lightning audit is a practical assessment of your building’s vulnerability to lightning strikes and surges. It checks whether the property:
Can safely absorb and redirect lightning energy (through earthing and external protection)
Has surge protection to guard against damage to electronics and electrical systems
Complies with SANS 62305, SANS 10313, or other South African regulations
Has any visible or hidden weaknesses that could lead to injury, fires, or costly equipment failures
At Bolt Guard, we perform full, certified audits—but there are some checks you can start with yourself.
Step 1: Walk Around the Exterior
Begin with a visual survey of the outside of your home, office, or building.
Look for:
Tall elements such as chimneys, aerials, water tanks, solar panels, or satellite dishes that extend above the roofline
Absence of air terminals (lightning rods) or conductors
No signs of conductor cables running from the roof to the ground (usually copper or aluminum)
Metal structures that are isolated (e.g. a fence or gate motor) and not bonded to the main structure
💡 If you see no lightning rods, grounding conductors, or visible earth rods, your building may have no protection system at all.
Step 2: Locate and Inspect the Earth Termination System
Lightning protection systems must have a way to safely discharge energy into the ground. This is usually done through earth rods or earthing rings.
Look for:
Metal rods near the building’s foundation (copper, galvanized steel, or stainless steel)
Thick bonding cables running from the top of the structure to ground level
Signs of corrosion, loose bolts, or frayed conductors
📌 Did You Know? Even a well-installed rod can become ineffective if the soil is too dry, rocky, or has high electrical resistance. That’s why testing is essential.
Step 3: Check Internal Surge Protection
Even if lightning doesn’t hit your building directly, nearby strikes can cause voltage surges that travel along power lines and into your home or office.
Look at:
The main DB board (distribution board). Is there a surge protection device (SPD) installed?
Are there secondary surge protectors for key circuits like security systems, internet routers, solar inverters, and gate motors?
Have any devices burned out, reset, or failed recently after storms?
🚫 Plug-in surge strips are not a substitute for a proper SPD installed in your electrical system.
Step 4: Assess Your Building’s Risk Profile
You should also think about your environmental and operational risk:
| Factor | Risk Level |
|---|---|
| Located on a hill or open terrain | High |
| Has tall structures or towers | High |
| Property has sensitive equipment (IT, solar, industrial) | High |
| History of storm damage | High |
| No formal protection installed | Critical |
If your building ticks two or more “high risk” boxes, it’s strongly recommended to get a professional inspection.
Why a Professional Lightning Audit Is Essential
While a DIY lightning audit is a great first step, it has limitations. A professional service like Bolt Guard provides:
✔️ Certified Testing and Measurement
We test the soil resistivity, continuity of bonding conductors, and the resistance-to-earth to ensure compliance with SANS 62305-3.
✔️ Risk Assessment and Design
Every building is different. We use data from SA lightning density maps, structure geometry, soil type, and more to assess your risk and design a system that works.
✔️ Insurance-Grade Reports
If your insurer or regulatory body requests proof of lightning protection, our reports and certificates satisfy these requirements.
When to Call Bolt Guard
You should contact us for a professional assessment if:
- You have no visible lightning protection on a building taller than 2 stories
- Your system hasn’t been tested in the last 3–5 years
- You’re installing or expanding solar power systems, CCTV, or other sensitive equipment
- You’re building a factory, warehouse, lodge, school, or hospital
- You’ve experienced equipment damage or unexplained outages after storms
- You want to ensure SANS compliance for insurance, construction, or certification purposes
What You Get with Bolt Guard
When you choose Bolt Guard, you’re getting:
📏 Full lightning protection system design
⚡ Surge protection and internal system upgrades
🧪 On-site testing and certification
🧰 Maintenance and annual evaluations
✅ Peace of mind, knowing your people and property are protected
We service residential, commercial, industrial, and agricultural properties across Gauteng and beyond.
Contact Us
Contact Details
Email: solutions@boltguard.co.za
Tel : +27 71 011 9343
Operating Hours
Monday to Friday
8h00 – 16h00
