What is a PVC Drain Pipe?

PVC drain pipe, or perhaps more generally, PVC pipe, is the ubiquitous white tube most often used in plumbing applications. It is typically used to allow water to pass from one location, such as a roof, to another location, such as a sewer or gutter. Polyvinyl chloride pipe, or PVC pipe, is more often used to remove water, rather than supply it for consumption. Still, despite PVC's numerous benefits, including lower costs, and easier installation, according to the National Sanitation Foundation (NSF), copper pipe is actually the most commonly used piping in homes.

Proper drainage within and away from homes and buildings is important to prevent water damage to the structure. It also helps protect the surrounding landscaping. In addition to transporting water, PVC pipe can also be used to dispose of sewage.

While PVC piping can be used for potable and and non-potable water, it is most commonly used for non-potable water. When PVC piping was first introduced to the market, there were concerns that PVC and other plastic piping leaked harmful chemicals into the water. Since then, industry standards have been developed and piping that is appropriate for water is marked with designations such as NSF-61.

PVC drain pipe is often preferred over other forms of drainage pipe, including cast iron pipe, flexible tubing, or galvanized steel pipe. There are numerous benefits to PVC piping. One such benefit is that, when properly installed, it is impervious to root invasion and crush-resistant. Another benefit is that PVC pipe is typically cheaper than other alternatives such as copper or galvanized steel alternatives.

PVC drain pipe comes in several sizes. In the US, the most common size for water drainage is about 3 or 4 inches (about 7.6 or 10.2 cm). Those installing PVC piping should check with their municipalities to determine whether regulations over PVC pipe size, length or degrees of bend are in effect.

Most experts advocate a 4 inch (about 10.2 cm) diameter PVC drain pipe for drainage. They also strongly advocate avoiding bends, or "elbows," of 90 degrees unless it is where the downward pipe meets the ground. Instead, experts suggest a looser angle, such as 45 degrees followed by a small length of straight pipe and another 45 degree bend, or two 45 degree bends together, to achieve the total bend necessary. A single 90-degree bend can restrict water flow and make it more difficult to unclog the pipe.

Polyvinyl chloride was discovered in the 19th Century but its commercial uses were not realized until the 1920s, when additives were found to make it more pliable and easier to produce. Most hardware or home supply stores carry a full line of the pipes, joints and pipe fittings, as well as the sealants and tools necessary to finish the drainage project.