Installing a cut-in electrical box with Madison straps allows you to easily add a new electrical outlet into an existing wall without having to cut out and replace large sections of drywall. Madison straps provide a simple and secure way to mount a new electrical box between the wall studs. With some basic electrical knowledge and the right materials, installing a cut-in box is a straightforward DIY project.
What You’ll Need
Before starting the installation, make sure you have the following materials:
- Cut-in electrical box – This is a specially designed electrical box that can be mounted between wall studs through a hole cut into the drywall. Make sure the box matches the size of your electrical outlet.
- Madison mounting straps – These metal braces allow secure attachment of the cut-in box to the wall studs.
- Electrical outlet – Choose the appropriate outlet style and amperage for your needs. 15 amp outlets are common for general home use.
- Electrical wires – Use 12 or 14 gauge NM electrical wire with ground. The amount needed depends on box location.
- Wire connectors – To join the wires from the new outlet to your existing electrical circuit.
- Drywall saw – For cutting hole to fit electrical box. A simple hand saw or power saw like a RotoZip works well.
- Screwdriver set – Both Phillips and flat head screwdrivers in various sizes.
- Stud finder – To locate wall studs for mounting the box.
- Drill/driver – For driving screws to secure the box and wires.
- Electrical tape – For securing wire connections.
- Drywall screws – For mounting Madison straps to wall studs.
- Wall plate – Matches your electrical outlet style.
Safety Tips
- Turn off the power at the main breaker before starting. Verify it’s off with a voltage tester.
- Follow all electrical and building codes for your local area. Permits may be required for some work.
- Wear safety glasses when cutting drywall or drilling pilot holes.
- Use a circuit tester to verify the outlet is correctly wired before restoring power.
- Hire a professional electrician if you lack the knowledge or experience with electrical systems.
How to Install the Cut-In Electrical Box
Step 1: Turn off power at the main breaker box. Use a voltage tester to verify it is off.
Step 2: Determine the exact box location on the wall. Use a stud finder to locate the nearest wall studs. Position the box between studs.
Step 3: Mark the wall for a hole centered on the box location. Make the hole slightly larger than the box outline.
Step 4: Use a drywall saw to cut out the hole through the wall. Make neat cuts for easy drywall repair later.
Step 5: Insert the new electrical box into the wall opening. The edge of the box should fit tightly to the drywall.
Step 6: Position and align the Madison mounting straps on the sides of the electrical box.
Step 7: Use a screwdriver and drywall screws to secure the Madison straps firmly to the wall studs on each side.
Step 8: Feed the electrical wire through the box into the wall cavity. Make sure you have enough length to work comfortably.
Step 9: Connect the wires from the new outlet to the existing circuit wires with wire connectors. Follow standard wiring color codes.
Step 10: Carefully fold the wires into the electrical box with the outlet oriented correctly. Attach the outlet to the box.
Step 11: Install wall plate on outlet box to complete the external appearance. Test outlet before closing up the wall.
Step 12: Patch drywall opening with joint compound and drywall tape for smooth finish. Prime and paint repaired section.
Step 13: Turn circuit breaker back on. Use a circuit tester to verify proper function of new electrical outlet.
FAQs About Installing Cut-In Electrical Boxes
What type of cut-in box should I use?
For typical residential wiring, a standard 4” x 2-1/8” rectangular metal box works well. Match the size to your outlet style. Plastic boxes can also be used.
How do I locate the wall studs?
Use an electronic stud finder tool on the wall to find the stud edges. Mark them lightly in pencil. Studs are normally 16 inches apart.
Can I install the box horizontally?
Yes, the box can be mounted horizontally between vertical studs. The installation steps are the same. Just position the box accordingly.
What if there are no nearby wall studs?
You may need a special brace inside the wall cavity to safely mount the electrical box. Hire an electrician if you can’t find adequate support.
Should I use armored cable or NM wire?
Standard NM (nonmetallic) 12 or 14 gauge electrical sheathed cable is suitable for most cut-in boxes. Use wiring appropriate for your electrical system.
What if there’s insulation in the wall cavity?
Carefully clear any insulation away from the box area to prevent interference with the wires. Stuff extra insulation around the sides.
How do I repair the drywall hole neatly?
Use drywall joint compound and tape to fill holes and seams for a smooth finish. Lightly sand before priming and painting the repaired section.
Can I install a cut-in box in a tiled wall or backsplash?
Yes, the same techniques apply. The box will be visible so take care to position it neatly. Seal edges to prevent water getting in.
Do I need a permit for this project?
Building codes vary. Some areas require permits for any electrical work. Contact your local building department to determine requirements.
Tips for a Successful Cut-In Box Installation
- Take time to carefully measure and position the box between studs before cutting the wall.
- Shrink or expand the hole slightly for a snug box fit. Any gaps should be filled in.
- Secure the Madison straps with at least two screws top and bottom screwed firmly into the studs.
- Avoid kinking the wires when coiling them into the box. Leave some slack if needed.
- Wrap electrical tape around wire connector splices for a stronger, moisture-proof connection.
- Test the functioning outlet before closing up the wall access. It’s easier to troubleshoot at this point.
- Smooth out drywall repairs thoroughly to match the surrounding wall area. Imperfections will show when painted.
- Label the new electrical circuit at the breaker box for easier identification and maintenance later.
- Consider installing the box at countertop backsplash level to allow plugging in appliances easily.
Conclusion
Adding a new cut-in electrical box using Madison mounting straps provides a neat, secure way to expand your electrical system into existing walls. For DIYers with basic electrical knowledge, it is a straightforward project that can be completed in just a few hours. Paying attention to safe practices and carefully following the steps for cutting drywall, positioning the box, connecting wires, and making repairs will result in a quality installation that looks professionally done. With the convenience of a new electrical outlet exactly where you need it, a Madison strapped cut-in box is one of the handiest improvements you can make in your home.