QUOTE(JinXXX @ May 10 2012, 11:18 AM)
if im not mistaken..
electrical always comes down from ceiling in straight line..
and for lighting point dont drill horizontal/vertical to the wall
water piping is from the bottom usually follow the same rules as electrical in some sense
electrical wire to socket mostly from below. As the socket place 1ft up from floor. So it is kind of waste the wire lenght to lay from ceiling down. For wall light, yes. It come down from ceiling.
Light switch wire mostly is from top. Cause the wire is to the ceiling light.
So far I haven't see any wire lay horizontol. Unless the socket is loop very near.
Why you have very less kena the wire when drill is, if the wire lay inside the conduit, when the drill bit kena the wire, the wire will move away. Cause the drill bit is rotate at high speed and the wire is round with flexibility. Unless no room for the wire move.
For piping, mostly run horizontol from tap to tap to toilet bow to shower. Just watch carefully around the height of the toliet bow inlet water. And the height of the inlet hole for sink tap. Piping don't bend up or down alot as it require many elbow and cost $. And it cause the pressure low too.