Running Electrical Cable Through Floor Joists

A favorite target of electrical inspectors is the improper use of non metallic cable nm in exposed locations such as basement foundation walls or along the face of studs and joists in unfinished framed spaces.

Running electrical cable through floor joists. The hole cannot be larger than one third the depth of the joist so the maximum hole size for a 2 12 joist actual size 1 1 2 x 11 1 4 in is 3 3 4 in. Otherwise you can run them along the bottom of the joists if you install a running board which can be as simple as a 1x2 nailed to the bottom of the joists. Adding a new ceiling light direct wiring an attic fan or installing any other type of overhead electrical fixture requires access to electricity. Run the free end of the cable to the next stud cavity location.

Then pull the cable through the wall plate and out the next wall box opening. Cutting notches and drilling holes in joists. Strip the end of the sheathing attach the wires to the fish tape and tape them in place. I d run it close to and parallel with some other obstruction e g a duct or pipe that will already have to be dealt with if the basement is finished later.

Attaching an electric wire under a ceiling joist. Staple the cable to the 1x2. Make sure to use approved attachment methods drilling holes through joists or stapling the cable where required. Diameter plenty big enough for running cable.