I would like to add an outlet to my back yard. In my basement there is a 20 amp circuit that runs from the breaker panel to my garage. Can I tap into the circuit in the middle of the run essentially forming a Y. The bottom part of the Y being at the breaker panel and one branch of the Y runs to the garage and the other branch runs to the backyard. I want to put a GFCI on the outside outlet and there is already one in the garage.
The main problem with this approach is that if you simply cut the cable in half, there won't be enough slack in the wires to get sufficient length-in-the-box (6" per NEC) for wiring the intermediate splice. Oops! I would extend from the garage outlet instead -- you can simply tap off its LOAD terminals and have GFCI protection for the outdoor outlet without putting another GFCI in.