How to Install New Pipes

Jim Mallery | Improvement Center Columnist | February 14, 2012

If you have some DIY skills, consider expanding those talents to plumbing. Whether you are using copper or plastic pipes, it's relatively simple.

Whatever the need, whether you are adding plumbing or need to replace pipes, the process is the same. You need to cut the pipes to the correct length and secure the various connections. Pretty simple. Here are some things you need to know.

Plastic Pipes

Plastic water pipes now are common. There are two kinds: CPVC, which is rigid; and Pex, which is flexible and can be bent around wide corners.

Plastic has two advantages over copper--cost and ease.

A section of ½-inch, 10-foot CPVC will cost about $7, whereas copper will be around $12.

Gluing the joints is very simple. First you wipe the two pieces with primer, then spread a thin layer of glue over them. You push them together with a slight twist and hold them for a few seconds while the glue sets.

Plastic joints aren't forgiving. If you make a mistake, you have to cut it out and start over.

Plastic water pipes need room to accommodate their considerable heat expansion, which can be as much as a few inches per 10 feet.

Copper Pipes

Joints in copper pipes are soldered, a process called "sweating." It's easy.

You wipe the pipe and fitting with flux and push them together. You heat the joint with a torch, holding the solder against the edge of the joint on the side away from the flame. Eventually the solder will melt and be sucked into the joint. Once that happens, you pull the heat away, and wipe the joint with a rag.

Copper fittings can be reused, and a joint that is not quite right can be heated and reset. This makes it easy to practice soldering before doing the real thing.

If you are soldering amongst studs or other wood, spray the wood with water before starting. It will help reduce charring and the chance of fire.

A pipe that has any water in it will not solder. You have to drain your pipes. If you have a pipe with a cap on it, you may need to drill a small hole in the bottom of the cap to drain the water.


  1. Tube cutter (for both plastic and copper): $7 to $15. You can buy a stubby cutter designed for cutting pipe that already is installed in walls.
  2. Glue and primer: $5 to $6 each.
  3. Torch: A standard propane torch is fine if you are using ½-inch or ¾-inch pipes. If you are sweating large brass fittings, like a valve, you might want to get map gas, which burns considerably hotter than propane but costs about three times as much ($8 vs. $2.50). A propane-torch kit, which includes the starter flint, costs $15 to $20.
  4. Solder and flux: Combination package costs about $17.
  5. Heat-resistant cloth: $10. Optional, but it helps protect wood from the torch.

If you have trepidation about your plumbing project, phone the local plumber. But for most DIYers, plumbing is a snap: all it takes is some patience and the right tools.