The answer is definitively yes, it is possible to be affected by a lightning strike while inside a structure and in contact with plumbing. While a direct strike to a person in the bathroom is extremely rare, the danger comes from the massive electrical charge seeking the quickest route to the earth. This search for ground means that a home’s internal systems can become temporary pathways for the electrical current, making certain activities hazardous during a storm.
How Lightning Enters a Home
Lightning does not need to strike a house directly to pose an indoor threat; it often enters a structure indirectly through conductive pathways that extend outside. Utility lines, such as power, telephone, and cable television cables, are common entry points for the electrical surge. Even if a strike occurs some distance away, the resulting electrical pulse can travel along these lines and into the home’s wiring and connected devices.
Another pathway is through direct strikes to the structure itself, which can utilize metal components or the home’s grounding system to travel inside. Once the immense electrical charge is inside, it can spread through internal systems. Metal wires and bars embedded in concrete walls and flooring can also become conductors for the current.
Plumbing as a Conductor
The plumbing system presents a specific risk in the bathroom because it provides an extensive, interconnected path for electrical current to follow. Traditional homes often use metal pipes, such as copper or galvanized steel, which are excellent conductors of electricity. Once a lightning charge enters the home’s water system, these metal pipes can efficiently transmit the high-voltage surge.
Even in modern construction where plastic (PEX or PVC) pipes are used, the risk is not completely eliminated. The showerhead, faucets, and drain components are still typically made of metal and are connected to the larger plumbing network. Moreover, the water itself, particularly tap water, contains minerals and impurities that enhance its ability to conduct electricity, allowing the charge to travel through the stream of water or standing bath water.
The danger is amplified by a phenomenon called a “side flash,” where the electrical current jumps from one conductive material to another in its pursuit of the fastest route to the ground. Inside a shower, a person is simultaneously in contact with the conductive water and within close proximity to metal fixtures, creating an immediate and low-resistance path for the lightning’s current to jump. This makes activities like bathing, washing hands, or doing dishes highly inadvisable during a thunderstorm.
Staying Safe During Thunderstorms
To mitigate the risk of an indoor strike, avoid all contact with water and conductive materials during a thunderstorm. This means refraining from all water-based activities, including taking a shower or bath, washing dishes, and doing laundry. Stay away from electronics that are plugged into wall outlets, as the electrical system can carry the lightning’s surge.
Corded landline phones should be avoided, but cordless or cellular phones are safe to use because they are not directly connected to the home’s wiring system. Stay clear of windows, doors, and concrete floors or walls, which may contain metal components that could conduct electricity. Authorities advise waiting at least 30 minutes after the last sound of thunder before resuming outdoor activities or using water.