Running Copper Supply Lines
Copper is the preferred material for supply lines in most locales, although flexible or rigid plastic is permitted in some areas. Practice cutting copper pipe and sweating joints before you start.
Supply lines are usually routed so they do not cross drainpipes or vents. In most cases, it's easier to make the horizontal runs in the crawlspace or basement. Long runs and bends lower water pressure slightly.
Hammer arresters (Step 3) prevent banging noise when you turn off a faucet.
Copper pipe is easily punctured or dented, so position it out of harm's way and install nailing plates to the studs to protect pipes against errant nails.
Hot water is always on the left, cold water on the right.
Prestart Checklist
Time
About half a day to run supply lines for a sink and toilet
Tools
Drill, bit and bit extender, propane torch, fiber shield, tubing cutter, multiuse wire brush, groove-joint pliers, carpentry tools for installing braces
Skills
Accurate measuring and drilling, working with copper pipe
Prep
Install all or most of the drain and vent pipes; determine the supply routes
Materials
Copper pipe and fittings, flux, solder, damp rag