How To Extend A PVC Pipe

Extending a PVC pipe to make plumbing changes within your home can feel like an overwhelming task. Armed with a few basic pointers and the right tools, however, this sort of plumbing work is completely doable, even by a novice repair person.

PVC pipe consists of polyvinyl chloride and is a hard, white material used for sewer or vent lines in plumbing. All pipe of this variety that is the same nominal size, or trade size, has the same diameter. Extending PVC pipe is often done via an outer coupling, as this sort of attachment will not restrict the flow of water through the pipeline. However, if you are working on a pre-existing pipeline, use of this outer coupling may not be possible.

When PVC pipe sections attach to each other via a solvent glue, it is not possible to undo their connection. The solvent glue is far too strong to permit any kind of dissolution or removal. If you find that you need to alter the path of a PVC pipe connected in this way, you likely will have to cut out that section of the pipeline and replace it with a new connector.

Before cutting pipe, shut any water supply to the area off using a whole-house shut-off valve. Use a hacksaw or circular saw and carefully cut the replacement pipe to the appropriate length. Then, use the hacksaw to cut the pipe you plan to remove. Sand the pipe so that the edges are smooth without burrs.

Next, apply PVC primer to the outside of both the old and new pipe, as well as the inside of your PVC coupling. Brush PVC cement onto all three areas, and attach the pipes, holding them firmly for five seconds each to permit setting.

If your plumbing job requires additional extensions, continue cutting out old pieces of pipe and replacing them with couplings and new PVC piping until you reach the fixture or main plumbing branch.

You may also extend PVC pipes with special fittings called extenders. These pieces have a small end that fits inside a pipe and a larger end that matches the outer diameter of the pipe you connect. From the outside, therefore, the pipe will appear to be all one size. However, you are actually reducing the interior space of the pipe by using an extender. Note that interior fittings must match the nominal size of the PVC pipe.

To install a pipe extender, you will need to prime all surfaces that you will connect, as outlined above. Once again, you will then apply cement to the areas you had primed, and hold connected areas firmly for five seconds to set.

Another option for connecting two ends of PVC pipe is an inside connector. These have two small ends with a ring around the center that matches the circumference of the pipe itself. The ends fit into each pipe. Since these interior fittings can impact the functionality of the pipe, use a flow meter to determine if using them will prove problematic.

To install this sort of pipe extender, first prime the outside of the connector. Next, apply cement in the places you primed, and insert the connector into the two pipes you are joining. Hold firmly for five seconds to ensure the ends are secure.