Engineering
7 Lightning Protection Mistakes We See on Jamaican Buildings
Every storm season, we inspect buildings across Jamaica that already have some form of lightning protection — yet still suffered damage when lightning struck nearby. In most cases, the problem is not that the owner ignored lightning risk. The problem is a system that looks correct but has a hidden gap. Here are the seven mistakes we see most often.
1. Air terminals with no low-impedance path to ground
A lightning rod on the roof is only the first step. If the down conductor is too small, poorly routed, or corroded at the connections, the strike energy will find its own path — often through building steel, electrical conduit, or data cables. This side-flashing is one of the most destructive failure modes, and it usually happens in buildings that "have a rod" but never had the full system engineered.
2. Grounding that was never tested
Jamaican soil conditions vary dramatically. Coastal coral rock, inland clay, and limestone all behave differently. A grounding system that reads acceptably when installed may degrade as soil shifts, connections corrode, or nearby construction disturbs the earth. We regularly find rods driven into dry rock or loose fill with resistance far above the 10 ohm target. Without periodic testing, you do not know if your ground is still a ground.
3. Surge protection missing at the panel
A well-designed lightning protection system intercepts direct strikes and routes them to earth. But nearby strikes — within a kilometer or less — induce transients on power and communication lines entering the building. Without panel-level surge protective devices (SPDs), that energy rides the mains straight into your distribution boards, servers, and machinery. A lightning rod does not stop this.
4. One SPD, no coordination
Putting a single surge protector at the main panel is better than nothing, but it is not always enough. Sensitive equipment like PLCs, gate controllers, access control, and network switches need coordinated protection at the board or device level. If the first SPD is too far from the equipment, the transient can regenerate between panels. A layered SPD strategy protects each stage.
5. Bonding that ignores external metal
External metalwork — antenna masts, solar panel frames, satellite dishes, HVAC ducting, and metal roofs — must be bonded to the lightning protection system. If a strike attaches to an unbonded mast, the energy cannot reach the designed path and will arc to whatever is nearest, often the building wiring or the equipment the mast was supposed to serve.
6. Adding a generator or solar array without updating the system
When a building adds backup generation, solar, or a new service entrance, the lightning protection and grounding topology changes. New conductors change the impedance paths. A strike can now enter from the generator pad, solar inverter, or transfer switch in ways the original design did not anticipate. Any major electrical addition should trigger a lightning protection review.
7. Treating certification as a one-time event
We see certificates on walls from five or ten years ago. Lightning protection systems are physical infrastructure exposed to weather, vibration, and corrosion. A certificate from 2018 does not mean the clamps are still tight, the rods are still deep, or the SPDs have not degraded. Annual inspection and re-certification is the only way to know the system is still intact.
What to do now
If your building has any of these gaps, the next storm season is not the right time to find out. Request a lightning protection survey that includes:
- Visual inspection of air terminals, conductors, and bonding
- Ground resistance testing at key points
- SPD inspection and coordination review
- External metalwork and new additions check
- A certification report with a re-inspection schedule
A complete system is not expensive compared to replacing one fried generator, one production line, or one security network. It is also far less expensive than the downtime that follows a strike.