Outdoor electric wiring
#1

I want to run an electrical line from my house to my garage. Problem is that there is a concrete sidewalk in the way. Can I run the cable under the sidewalk myself? If so, what type of machinery would I use and how do I do it?
#2
Going under your average 4-foot sidewalk is normally trivial. The technique is pretty-much the same as running a sprinkler line under the sidewalk (you can sometimes read about it in a landscaping book). Difficulty depends on the soil type. Sometimes you can just pound the conduit through. Or attaching the garden hose to the conduit and using flowing water to "drill" underneath almost always works (except in very heavy clay, or in very rocky soil). Start by digging a trench up to the sidewalk from both sides. After that, it's probably a five-minute job.