5 Main Types of Plumbing Pipes Used in Homes

Pros and Cons of Plastic and Metal Pipes

Brancko Mickovic/Getty Images

Whether hiring a plumber or taking on a do-it-yourself plumbing project, the experience can be confusing because of the choice of several types of plumbing pipes. Eventually, pipes' uses tend to blend together. Which type of pipe should be used for water supply, drainage, sewer, and even for the exterior? The answer is not as clear as it may have been in the past when the main pipes of choice were galvanized steel or cast-iron.

PEX Pipe

PEX, or cross-linked polyethylene, pipe is one of the newest and most popular pipes to hit the plumbing market. PEX is used only to supply water. PEX is a pipe that is rigid enough to withstand the pressures of water supply but flexible enough to weave throughout walls, ceilings, basements, and crawlspaces. PEX has truly delivered water-supply plumbing into the hands of do-it-yourselfers and professional plumbers.

Check your local codes before installing this type of pipe. While it is commonly used across the United States, it is not legal everywhere. It must be well supported, and the fittings must be installed properly and tested, especially when installed behind walls.

  • Long-term capabilities untested

  • May leak with push-fit plumbing fittings

  • Cannot be recycled

PVC Pipe

PVC, or polyvinyl chloride, pipe is a drain or vent line type of plumbing pipe. PVC initially gained popularity because it was lighter and easier to work with than traditional galvanized steel pipe. PVC pipe is moderately easy to install and requires little more than a hacksaw and a miter box to cut. PVC glues together with solvents.

Check your local codes before installing this type of pipe. While it is commonly used across the United States it is not legal everywhere. It must be well supported, and the fittings must be installed properly and tested.

  • Diameters clearly marked on the white surface of the pipe

  • Inexpensive and can be used for long runs such as for irrigation

  • Easier to work with than steel or copper

  • The pipe cannot be unjoined and must be cut

  • Glued pipes can be prone to leaking if not installed properly

  • Degrades in sunlight


Watch Now: Best Ways to Repair a Leaky PVC Pipe

Rigid Copper Pipe

Rigid copper is often used for water supply lines within the home. Rigid copper is easily cut with a hacksaw or with a special copper tube cutter. Rigid copper pipe is great for water supply because it does not come with any health risks.

Among the multiple options for connections, the best is the solder-type connection. The solder connection requires experience coupled with safety protocols.

  • Handles heat well

  • Stands up against intense pressures

  • Easy to recycle and waste copper pipe even has monetary value

  • Difficult for do-it-yourselfers to work with due to soldered connections

  • Expensive

ABS Pipe

ABS (acrylonitrile butadiene styrene) pipe is mainly used as a vent and drain line. ABS pipe looks very much like PVC pipe, except that it is black and slightly softer. Be sure to consult your local codes to determine where you can use this product.

  • Stronger than PVC pipes

  • Good for underground exterior use

  • Works well in cold temperatures

  • Often not permitted by building code

  • Warps and deforms at certain temperatures

Flexible Type Connection

Flexible connections, also called Flexi's for short, are used for final connections to appliances. Like water heaters, toilets, sinks, etc. They are used on gas & domestic water and come in many lengths & sizes. BUT local codes must be followed. They are not permitted inside walls or floors.

  • Fits in tight, unusually shaped areas

  • High heat tolerance

  • Expensive

  • Thin and prone to breaking

Galvanized Steel Pipe and Cast Iron

Two additional types of pipe are sometimes found in older homes and are infrequently installed, especially by DIYers: steel and cast iron pipe.

Galvanized steel pipe was used for decades for drainage, water supply, gas supply, and any number of other purposes. While galvanized steel pipe is still around (particularly for gas supply) it is far less used and is never used for water supply in new construction or remodel projects. Each end of the pipe is threaded, and individual pipes are screwed into each other with connecting fittings.

Cast iron pipe was often used for sewer and other drainage purposes. Cast iron pipe is still found in many homes. Cast iron pipe is viable until the point that it rusts completely through. Cast iron is very heavy and difficult to cut. Retrofits tend to replace cast iron pipe with rigid plastic pipes such as ABS.

  • There are no pros for the use of galvanized pipe anymore. However, it is still required for use in some applications, like natural gas.

  • Galvanized steel pipe eventually corrodes and blocks water flow.

  • Some galvanized steel pipe may pass lead into the water supply.

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Plumbing and Pipes: Healthier Choices. Environmental Working Group.