Plumbing Pipe Types
Residential plumbing comes in many varieties of pipe, and you may find that a home has several different types of pipes for various purposes.
- Copper pipes have been in use since the 1960s. They are durable – fittings stay tight and are not prone to leaks. They are suitable for use with drinking water, heat tolerant, have a long life span, and can be recycled once their useful life has ended. They come in various thicknesses making them suitable for interior hot and cold supply lines, and outdoors for underground (buried) service lines. However, copper pipes are rather expensive (approximately $290 for 100 linear feet) and in older homes, copper pipes may contain lead-based solder.
- PVC (polyvinyl chloride) pipes never rust or corrode and unless they are exposed to direct UV light, they will not degrade over time. They are typically used for toilets, sinks, bathtubs, and/or vent stacks. They are capable of carrying high water pressure, and they are inexpensive and easy to cut install (just use connector pipes and PVC glue). However, they can’t handle very hot water as they can warp, which makes them unsuitable for laundry use.
- CPVC (chlorinated polyvinyl chloride) pipes are commonly used for drinking water due to their chlorine levels. They are easy to work with, can be used for hot or cold water supply and are more flexible than PVC pipes. However, if they freeze, they will split; and they cannot be recycled.
- PEX (polyethylene) pipes are great for plumbing retrofits and new additions. They are easy to snake through walls, making it possible to use one length of pipe across the entire house; and since they are heat resistant they can be used for both hot and cold water supply.
- Galvanized steel pipes are rarely used in modern construction due to the presence of lead, their susceptibility to internal rusting, their weight and difficulty of installation, and tendency to discolor water. Homes built between 1930-1980 may contain galvanized pipes, which will be revealed in the inspection. These pipes will need to be re-plumbed to eliminate the toxic lead hazard.
- Stainless steel pipes are strong and corrosion resistant. However they are even more expensive than copper and so are rarely used in residential applications.
- Cast iron pipes have been used for many, many years. They are durable but extremely heavy and difficult to work with. If an older home has cast iron pipes and you need to replace a section, you can use PVC since PVC joints work well with cast iron.
- PB (gray plastic polybutylene) pipes are used as cheap replacements for copper pipe. But you get what you pay for, as these pipes are prone to leaking.
- HDPE (high-density polybutylene) pipes are flexible, durable, and corrosion resistant and can be used for many different plumbing applications.
What about the valves, drains, and faucets that are connected to the home’s piping? Again, there are many options and the home will likely contain most if not all.
First, most people think “faucet” when they are talking about plumbing “fixtures” but plumbing fixtures refer to any device connected to a plumbing system whether its intended use is to supply water or to drain it.