Where to Run Wiring in an Attic

General Placement

• In most cases, it's best to run wiring in an attic near the edges of the attic where the rafters meet the attic floor. This provides solid rafters at regular intervals for attaching junction, switch and outlet boxes. It's the best strategy if you're running wiring in the attic to supply other parts of your home with new wiring. It also allows your wires to rest against the attic floor or, in the case of some unfinished attics, on top of the attic's insulation. Placing new wiring close to the attic walls will prevent you from tripping over it or displacing it with boxes when you move through the attic and use the space for storage.

Rafters

• Overhead rafters are another effective place to run wiring in an attic. This is especially true if the new wiring originates at an existing fixture, such as an overhead pull chain light. Running wires along rafters should be your first plan of attack if you're installing an attic fan or light. Instead of laying wires along the attic floor, you can drill into rafters to create holes that the new wiring slides through, or install brackets that hold the wiring against the rafters, to keep it from hanging down.

Accessibility

• Wherever you choose to install wiring in your attic, you must ensure that all boxes are readily accessible. This requirement is a standard part of building and electrical codes because it facilitates inspection. However, it will also allow you to add new wiring in the future or repair wiring if your project doesn't work out as expected. Don't run the wiring under insulation or in isolated corners of the attic where it will be hard to access or vulnerable to water leakage from the roof or a nearby window or vent.

Self-Installation Risks

• Depending on the scope of your wiring project, you may need to consult or hire a professional. Any wiring project that places additional strain on your home's electrical system is potentially dangerous unless you understand the system's limits and the proper installation techniques. If you don't comply with local building codes, your home won't pass an inspection should you choose to sell it, and damage from faulty wiring might not be covered by insurance.