How GFCI Receptacles Keep You Safe


By Max Alexander of This Old House magazine


A ground fault happens whenever electricity escapes the confines of the wiring in an appliance, light fixture, or power tool and takes a shortcut to the ground. When that short cut is through a human, the results can be deadly. About 200 people in the U.S. alone die of ground faults each year, accounting for two-thirds of all electrocutions occurring in homes.

To prevent such accidents, Charles Dalziel, a professor of electrical engineering at the University of California, invented the ground-fault circuit interrupter (GFCI), in 1961. Most of the time, his invention does nothing; it just monitors the difference in the current flowing into and out of a tool or appliance. But when that difference exceeds 5 milliamps, an indication that a ground fault may be occurring, the GFCI shuts off the flow in an instant — as little as .025 second.

GFCIs are required by the National Electric Code in all new kitchens, bathrooms, crawl spaces, unfinished basements, and most outdoor receptacles. Owners of older houses can retrofit $10 GFCI receptacles at those locations or have GFCI breaker switches (which run as much as $108 for 50-amp models) mounted in the main breaker panel. Portable GFCI adapters, which plug into regular wall receptacles, are available for about $40.

“The great thing about GFCIs is that they protect you whether or not your wiring is grounded,” says Bill Grande, manager for safety products at Leviton, a manufacturer of GFCIs. Because lightning and other power surges can damage a GFCIs delicate circuitry at any time, Grande recommends the following monthly test: Plug in a light fixture and turn it on. Then push the device’s test button. If the light stays on, the GFCI needs to be replaced.

<script type=”text/javascript” src=””></script><br />Transcript provided by InterNACHI, the <a href=””>home inspector</a> organization

One of the most common comments I make when inspecting a home is one that points out moisture damage at the exterior door jamb. There are typically a couple potential causes for the damage. It is a common issue that can sometimes be repaired without replacing the door. Using materials that resist rot can help minimize further damage as well as installing a storm door.  Depending on your skill set and the amount of damage, this might be a project you could do yourself. Sometimes the damage can extend to the sub-floor or rim joist. These conditions are more difficult to address on your own.



  • Ground water
  • Evaporation
  • Plumbing leaks
  • Poor venting practices



