How To Wire A Storage Shed, Office Shed or Basement

Some of the basic code requirements relating to electrical wiring of basements or any place else in the house are:

• Any wall that is greater than 2' in a bedroom must have a receptacle.
• You must always be within 6 feet horizontal of a receptacle. This generally means that receptacles can be no farther apart than 12 feet and a receptacle must be within 6 feet of a door. This is measured along the wall surface, you can't cut corners.
• Switched receptacles must be half hot to be included in the "within 6 foot of a receptacle" rule.
• Hallways longer than 10 feet must have a receptacle.
• Any unfinished areas of the basement must have a GFCI protected receptacle.
• Switched outlets are able to replace a light fixture on the ceiling except in kitchens or bathrooms.
• Smoke alarms required in sleeping rooms and adjoining areas.
• Smoke alarms must be wired in series so if one is activated then all alarms go off.
• Smoke alarms must have power from the building and a battery back up.

For more detailed code information related to wiring a basement or other projects you should read the article Basic Electrical Codes.

step 3 Locate And Install The Electrical Outlet Boxes

"Handy boxes" are the plastic boxes that are used to hold outlets, switches, lights, smoke detectors and low voltage wiring. Locating the handy boxes is the first step in installing shed outlets. The top of an electrical handy box used for outlets is typically at 14 inches above the floor to the top of the box. (code says 12" to the center of the box, and you need to account for any floorings you install in the shed). To make your installation look good you should mark the all the studs where you will install a handy box at 14 inches and then come back later and install the boxes. Many electricians use a piece of wood that is 14" tall and set the piece of wood on the floor in front of the wall stud that the new outlet will be on and draw a line on the stud at the top of the board.

How To Nail On A Handy Box: Handy boxes come with the nails pre-installed so you only need to nail them on. They are installed by lining up the top of the box with the mark you made on the stud and making sure the face of the box sticks out in front of the stud 1/2 inch and then nail it on. Repeat this process with all the outlets switches and light boxes you need to install. If you are in a area that is too tight to swing a hammer you can use a screw gun and simply screw thru the side of the handy box into the wall stud, grabber screws work best.

step 4 Locate And Install The Electrical Switch Boxes

Locate the switch boxes by marking the wall at 48 inches above the floor. Nail the box with the top of the box on the mark. Make sure the box sticks out past the stud a 1/2 inch by butting the plastic bumps on the side of the box against the stud.

There are two important things to remember when placing switch boxes next to doors on the shed:

1. If you are locating a switch box right next to a door you should make sure that the door will not swing to cover the switch or you will always need to close the door to get to the switch.
2. If the switch is right next to the door opening you should add a few scrap pieces of 2x4 lumber so the side of the box is at least 4 1/2 inches, (3 boards), from the door opening. This will insure that the door trim will not hit the switch when you are installing trim on the door.

step 5 Locate And Install Ceiling Light Boxes

The best way to locate a ceiling light fixture is to lay out the measurements and markings on the floor and then transfer that mark to the ceiling, especially if you want the light fixture centered or spaced evenly on the shed ceiling. Light fixture outlets are attached in the same way as other handy boxes. Ceiling electrical boxes are round.

step 6 Locate And Install Smoke Detectors

Smoke detectors are arguably the most important part of your basement wiring project. They are typically not required on a backyard shed unless you are using the shed as a sleeping room. They may save a life and that makes them very important. Building codes require that:

• There be a smoke detector in every sleeping room and the adjoining area.
• Smoke detectors must be connected so if one goes off then all of them go off.
• A minimum of 1 smoke detector on each story, this includes basements even if they are unfinished. Smoke detectors are not required in crawl space or attics if they are not habitable areas.
• The Smoke detector must have power from the building wiring and a battery backup. (Battery power only is ok if you are remodeling and are not removing finishes and there is no attic or crawl space to run wires in).

To put a smoke detector in a bedroom and adjoining area you use a round electric box that is used for a light fixture. They are usually attached to a ceiling joist halfway between the bedroom door and the bedroom light fixture.

step 7 Run The Wire Between The Boxes

Drill Holes: Before pulling wire you will need to drill holes in the shed wall studs. Use the 3/4 inch drill bit to drill a hole in the CENTER of the stud so siding and drywall nails cannot damage the wire. Electrical Codes require that they be no closer than 1 1/4" from the face of the wall studs. Drill about the same height as the outlets so the wire runs fairly straight across the wall, this saves the amount of wire you will need to use. If you need to drill close to the edge you can use a nailing plate to protect the wire.

Work On One Circuit At A Time: When wiring a basement, or backyard shed project, you should start at the end of the electrical run and work your way back to the first box in the circuit. From the first box in the circuit you will create a "home run" to the electrical panel which will be described in the next step

Pull Wire Into Electric Handy Boxes: When you pull wire into the handy boxes leave about 10 inches of wire hanging out of the boxes, 4 inches in the box and 6 inches in front, so you will have plenty to work with when it is time to tie up the switches and outlets.

Attach the wires to the shed wall stud within 8 inches of the box using a cable staple.

This image shows an electric outlet box in the middle of its run. The box on the far right is the end of the run. The wire travels left to the box in the center of the image. It then leaves this box and goes to a third box or a home run to the power panel.

The box on the left side of the double studs is a Data and Television cable box. Data and Television cable boxes should be placed on the opposite side of the stud from the outlet box to reduce electrical interference.

This image shows a cable tv box opposite a electrical outlet. They are seperated so the electrical wires do not create interference with the cable tv. Notice the staple within 8 inches of the box.

step 8 Run The Wiring Home Runs

After you have run the wires between the boxes you are ready to make the "home runs" to the electric panel. A Home run is the wire that goes from the first box in the cirucit to the electric panel. To pull a home run simply run a wire from the first box in your circuit to the electric panel. Leave about 10" hanging out at the handy box and 2' of extra wire after the wire enters the electric panel.

This image shows wiring on a shed wall. The wire going into the floor is the home run, it goes to the electric panel on the outside of the shed. Sometimes the electrical sub panel is installed on the inside wall of the shed. In a basement you will most likely go up to the ceiling or along the walls to make the home run). Nailing plates are only required when the hole for the wire is closer than 1 1/4" of wood protecting the wire.

step 9 Wire The Basement Switches, Lights and Outlets

Please read our articles on

How to wire single pole switches

How to wire three way switches

How To Wire outlets

How To Wire 220 Outlets (for 220 air compressors or welders)

Step 10 Installing A Circuit Breaker

When the new wire goes into the electric panel it will need a new circuit breaker. You should never add a new wire to a circuit breaker that already has a wire on it.

Read the article How To Install A Circuit Breaker to learn how to install a circuit breaker. If there is not room in your electric panel for a new circuit then you will need to install a sub panel. A sub panel will allow you to add more circuits.

Read How To Install a Sub Panel to learn how to do this.