10 Wiring Problems Solved

overlamping a fixture, wiring problem Illustration: Ian Warpole

PROBLEM #1
Overlamping is when a light fixture has a bulb with a higher wattage than the fixture is designed for

Illustration: Ian Warpole

PROBLEM #2
Uncovered junction boxes increase the risk of wire damage and shock

Illustration: Ian Warpole

PROBLEM #3
Lights flicker when it's windy because frayed wiring causes a short whenever the cables move

too few outlets, power strips Illustration: Ian Warpole

PROBLEM #4
Not enough outlets means you're likely to rely on extension cords and power strips

Illustration: Ian Warpole

PROBLEM #5
GFCIs shut down circuits in 4 milliseconds to prevent fatal shock

Illustration: Ian Warpole

PROBLEM #6
Overwired panels contain more circuits than they are rated to handle

aluminum wiring illustration Illustration: Ian Warpole

PROBLEM #7
Popular in the 1960s and '70s, unsafe aluminum wiring is a cheap substitue for copper

backstabbed wires illustration Illustration: Ian Warpole

PROBLEM #8
Backstabbed wires are more likely to come loose

Illustration: Ian Warpole

PROBLEM #9
Undergrounded (2-pronged) receptacles means your home has no way to safely conduct stray current

Illustration: Ian Warpole

PROBLEM #10
Plugs fall out of their receptacles when contacts are worn

knob and tube wiring Illustration: Ian Warpole

Knob and tube wiring may be covered with building insulation, which causes overheating

armored cable Illustration: Ian Warpole

Armored cable insulation should be checked every 5 years or so

two-wire plastic sheathed cable Illustration: Ian Warpole

Grounded receptacles cannot be retrofitted to two-wire plastic-sheathed cables

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It's not just the nation's power grid that's antiquated. The wiring inside many houses is also out of date, straining to supply our ever-growing collection of electricity-hungry appliances, lighting, and electronics.

"The circuits in these older homes weren't designed to power the many gadgets of modern life," says electrician Allen Gallant, who has wired six This Old House TV project houses.

The signs of strain may be obvious — a tangle of extension cords and power strips sprouting from a single outlet — or lurking unseen behind walls, ceilings, and cover plates.

Protecting the Box
Fuse boxes, like this one, are less common these days than circuit breaker panels, but they work just fine — unless someone installs fuses with a higher amperage than the wires can safely handle. That can cause the wires to overheat, damaging their protective insulation and increasing the risk of fire. Once the insulation has been damaged, the danger remains even if the offending fuse is replaced with one that's the proper amperage. To fix it, the old circuit must be rewired.

Some wiring problems are just inconveniences. But others can pose serious fire or electrocution hazards. If you're buying a house (especially one that's more than 50 years old), or if you've never had your wiring inspected, it's a good idea to hire a licensed electrician to give your home a thorough going-over. "He'll look at the insulation on the wires to see if it's dried out and fraying, he'll look for corrosion in the service panel, and he'll look to see if a previous owner did anything unsafe," Gallant says. After that, he recommends getting a quick follow-up inspection every five years.

Don't be alarmed if the inspection turns up code violations. Each time the electrical code is revised, old wiring is "grandfathered," on the assumption it was installed correctly. Code only requires you to update wiring in rooms being gut-renovated.

To help you assess the state of your own electrical system, we've asked Gallant to identify the 10 most common wiring problems he sees, the dangers they pose, and his recommended solutions.

Remember: Anytime you work with wiring, be sure to turn off the circuit at the main breaker panel.

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