How to Wire a Concrete Block House

Wire a concrete block house while you lay the blocks.

Concrete block house are popular in areas where the underlying soil is stable and the climate is temperate. Since concrete is a poor insulator, block houses are not energy efficient in locations that experience extreme temperature fluctuations. Wiring a concrete block home is slightly different from wiring a wood frame home because the blocks present a solid barrier to horizontal wiring. With a little knowledge of basic masonry techniques, electrical skills and the correct tools, you can wire a concrete block house.

Things You'll Need

• Breaker box Wire (various amperage) Conduit Receptacle boxes Grinder with 4-inch wheel Reciprocating saw with masonry blade Switches and outlets Electrician tools

Instructions

1. Design your wiring layout before you begin laying the concrete blocks for the walls of your house. The most efficient way to wire through blocks is to allow for your switches and outlets by installing conduit within the blocks as you form the walls.

2. Determine the location of your breaker box and choose adequate amperage to handle all your future electrical needs. Check your local code or choose a 200 AMP box to be on the safe side. Since the foundation required for a concrete block house should be slab on grade, a utility closet is the most likely location for the breaker box.

3. Diagram your wiring plan. In the interior walls, you may run the wiring horizontally through the wood studs, just as you would do for any wood frame home. National Electrical Code requires that you place outlets no further than 8 feet apart on all walls so you must make provisions to wire the outlets in the concrete block walls.

4. Plan to bring your wiring in from the top of the concrete block wall. Since your blocks will rest upon a solid slab, you must make alternate arrangements to get the wire to the outlets and switches.

5. Cut a section out of the concrete block with the grinder when you reach a height of 19 inches on your block wall. Although 19 inches is the standard height of a wall outlet in living areas, you may alter it a little bit if local code allows.

6. 

   Attach a receptacle box in the hole you cut in the block and brace a piece of ½-inch conduit, cut just long enough that it will reach your receptacle and still extend upwards into the future attic space. Some receptacle boxes come with a punch-out on top where you can insert the end of the conduit. If not, drill a 5/8-inch hole and insert the conduit.

7. Continue laying the concrete blocks, installing more outlets where desired and installing light switches 48 inches from the ground. In addition, outlets and switches in the kitchen area will all be 48 inches from the ground.

8. Run your wire when you finish laying the blocks. The most important rule to remember here is to never splice wires in between junction boxes. To do so is a fire hazard. Begin by running the wire from the junction box upwards to the attic and then running it into the first conduit. Insert two wires into the conduit, pushing them downwards until they exit into the receptacle box. Attach the wires to the outlet as described on the outlet package.

9. Repeat the process in the attic, using the second wire, along with another wire, to push into the second outlet. Wire as before. The trick here is to measure your wire before you cut it. Measure from the outlet box, up through the conduit, and back down the next conduit. Always cut the wires on the long side to allow for the stripping necessary when attaching the wires to the outlet.

10. Consider the power needs for your kitchen appliances. The microwave, refrigerator and stove must all be on their own breaker, meaning you must run a separate wire from the breaker box to each. In addition, put no more than two kitchen outlets on one breaker since running numerous appliances will overload a single circuit.

Tips & Warnings

• Consider having an electrician look over your wiring diagram before you begin or take it to your local building authority to make sure it meets building code.

• If you have any doubts about the wiring process, consider asking an electrician to wire the house for you. You can still install the conduit yourself.

Resources

• Order electrical supplies and tools online.