Your home may contain an odd collection of pipes, with some runs being made of one material, and other runs being made of other materials. Often, a mixture of materials can signal problems that may have been addressed by former owners of your home in Boston. Plumbing materials have changed over time, and I thought it might be useful to identify some of the most common plumbing materials.
Copper is the “gold standard” when it comes to plumbing materials. Copper is typically used on the supply side of the system. That is, copper pipes carry fresh water into your home, to your taps and water-using appliances. Copper is a metal, and has a distinctive orange color. In certain circumstances, copper can change color from orange to green. This usually happens with exposure to air.
Copper pipes can also be used to provide an electrical ground point for your home’s wiring. If you do your own wiring, only use cold water lines to provide an electrical ground. A ground fault that is dissipated through a hot water pipe can set up a galvanic reaction that can destroy the pipe, and leave a steamy mess behind.
Another copper caveat: if the pH of your water is naturally below 6.5, copper can leach out of the pipes into the water at levels that are considered unhealthy. Special filters can remove excess copper. Another approach is to raise the pH of the water at the intake to prevent copper leaching.
At various times, copper has been in short supply, so other less expensive materials have been used to on the supply side of residential plumbing. Galvanized pipe, which is often black in color, was used heavily in some home construction after World War II, but it is not commonly used today as a “first-choice” material. Galvanized pipe is treated iron pipe that can safely carry fresh water and natural gas.
Because it is made of iron, galvanized pipe can and does rust over time. Smaller diameter fresh water pipes are especially prone to this kind of long-term damage. Rust can build up in a galvanized pipe and is discharged from a faucet when the tap is opened. Over time, the rust can stain sink, tub and toilet fixtures. Many homeowners have chosen to replace galvanized pipe with more expensive copper or less expensive PVC to avoid the side effects of the long-term deterioration of galvanized pipe.
There are a number of different plastics that have been (and are) used for residential plumbing. Polyvinyl chloride (PVC) pipe is a white plastic material that can be used on both the supply side and the discharge side of a residential plumbing system. Chlorinated polyvinyl chloride (CPVC) is also used, as is flexible plastic supply tubing known as PEX. PEX can be used for short runs, but it can also be used under floors, in crawl spaces and in radiant heat systems. PEX is less prone to freeze damage than other piping materials, and does not require chemical epoxies for joints or connections.
Brass piping can be used in residential applications, but it tends to be expensive. Brass is an alloy of copper and zinc. The best grade of brass pipe has about 85% copper and has a distinctive reddish color. The lowest acceptable grade brass pipe has a copper content of about 67%. Generally, the lower the copper content, the more vulnerable the pipe is to deterioration. Using non-brass fittings with brass pipe can also set up a deteriorating reaction.
High quality brass is not affected by water and does not rust. It is a good choice for hot water supply lines and may be a suitable replacement for galvanized pipe. Brass is also widely used in plumbing fixtures, fittings and valves.
And then there’s lead. Even though the health implications of lead plumbing have been well documented, many older homes had (or still have) lead supply lines that connect the home to the municipal water supply. Lead supplies are easy to identify because they have a distinctive dull gray color, and are soft enough to be scratched by a screwdriver or similar tool.
Municipal water systems typically don’t have any lead supply lines left. If you have a lead water supply line carrying fresh water to your home, or think you may, contact us for advice on replacing your lead supply line with one made from a safer material. Lead should be removed from plumbing systems since it is a known hazard to human health.
If you need help identifying your pipes, or would like an estimate on pipe repairs or replacements, contact us at Boston Standard Plumbing at (617) 362-0377 anytime!