Fitting New Copper Lines

• 1). Attach the mixing valve to a horizontal piece of 2x4 that in turn is attached to vertical wall studs on each side. Use metal bracing and galvanized 1 5/8 screws to hold it in place. Attach the brass showerhead fixture also to a horizontal piece of 2x4 between two vertical studs.
  
  
• 2). Run new hot and cold copper lines (pipes) from your existing copper lines up to the bottom of the mixing valve--the hot line usually goes on the left side. Run one copper line from the top of the mixing valve to the brass showerhead fitting. Always prepare the copper joints (couplings) and fit all the water lines together so that they are in place before any soldering is carried out. Start at the existing water lines and work your way toward the mixing valve and brass showerhead fitting. Cut necessary new copper lines and prepare joints as follows.
  
  
• 3). Turn off water at the main shutoff valve. Drain both hot and cold lines of all water. Cut into the existing water lines by placing a tubing cutter over the copper pipe. Tighten the blade so it rests on the copper line. Rotate the cutter once before tightening and rotating a second time. Continue in like fashion until the copper line is cut. Do the same with the other existing copper line.
  
  
• 4). Sand the end of each copper line--1 inch--as well as the inside of two couplings. Apply lead-free soldering paste (flux) to all sanded areas using a small brush. Push the couplings onto the existing lines. Cut to the required length new pieces of copper line and apply the necessary couplings in the same way, working your way over to the mixing valve. Also cut and install the copper line between the valve and the brass showerhead fitting.
  
  
• 5). Uncoil 12 inches of lead-free solder from its spool and bend the last 2 inches 90 degrees. Turn on the propane torch and heat the first coupling, moving the flame slightly from side to side. Do the same on the back side of the coupling. When you hear the flux sizzle take the flame away. Touch the tip of the solder to the seam between the copper line and coupling, and if the solder melts, apply 3/4 inch of solder to the seam. Capillary action will suck the solder down between the coupling and copper line. Wipe away all excess solder with a rag, remembering that the coupling/copper line will be hot. Continue in like fashion until all couplings (and mixing valve/brass showerhead fitting) have been soldered.
  
  

Fitting the Sewer Line

• 1). Attach an ABS P-trap to the bottom of the shower base. First cut a new piece of ABS sewer pipe 12 inches long with the hacksaw and remove all burrs with a utility knife. Note that sewer pipes require a gradient so the waste will travel down the pipe. Contact your local permit office before any installation for the correct gradient. Depending on the location of your existing sewer line, you may have to cut the sewer pipe attached to the shower base less that 12 inches to create the correct gradient.
  
  
• 2). Wet one end of the new pipe and push it up into the rubber flange in the shower base. Apply ABS glue to the other end of the pipe as well as to the straight end of the P-trap.
  
  
• 3). Push the P-trap up onto the new ABS pipe, holding it for at least 30 seconds. Point the other end of the P-trap in the direction of the existing sewer line. In the same fashion, cut new sewer pipe and apply couplings as you need to connect the P-trap to the existing sewer pipe.