Plastic Plumbing Pipes

LESLIE: Well, if a plumbing project is on your to-do list – and especially if you’ve ever sort of dove into a plumbing project in your home – you know once you get into those walls you’re probably going to see a mishmosh of plumbing materials. Now maybe you’re seeing some things that are cast iron, some are copper, some are steel, some might even be brass. And depending on the age of your home, you might see everything in one area; you never know. But the future of plumbing and plumbing projects is using plastic.
 
TOM: Absolutely. And not everyone is a fan of plastic but, as we are about to find out, there’s no reason to fear plastic plumbing. Here to tell us why is This Old House host Kevin O’Connor and the show’s plumbing expert, Richard Trethewey.
 
And Kevin, in most homes, and especially older homes, you typically find a pretty wide variety of plumbing pipe material.
 
KEVIN: You got that right. In old houses, you’ll find all sorts of plumbing pipes. There’s steel and brass and copper and even cast iron. These materials have stood the test of time but they can be expensive and difficult to install. Some people think that the future of plumbing pipes can be summed up in just one word: plastics.
 
RICHARD: And there are a few options for running plastic plumbing pipes; for running water inside of a building, I think there are two. The first is PEX. The PE stands for polyethylene; the X stands for cross-linked. Now this is a process that makes the plastic not get brittle over time. Now you’ve seen it used on heating and we now run it on all sorts of plumbing systems and it’s flexible, so you run it much like wire inside of a building and it means very few fittings inside the wall.
 
The other choice for water is CPVC, chlorinated polyvinyl chloride. Now this comes in straight sticks and you actually put it together with fittings much like a copper pipe; you know with elbows and Ts and 45-degree angles.
 
KEVIN: So those are some options for water supply. How about the waste pipes?
 
RICHARD: I think there are two. One is PVC – polyvinyl chloride; it’s been around for years – and that’s usually a white pipe and fittings. And the other is ABS and that’s a black fitting. And it’s funny; in different parts of the country, one will be more popular than the other. But no matter what you do, always clean ABS and PVC before you glue. If you have a leak, there is no good way to repair it; you just have to cut it out and start again.
 
KEVIN: Alright. So it sounds like plastics have a bright future.
 
RICHARD. Absolutely. They do, but metal piping – especially copper – you know it still has a lot of advantages in many circumstances. I’m going to hang onto my soldering kit for just now.
 
KEVIN: And to see a video of all the options for plumbing pipes, visit us at ThisOldHouse.com.
 
TOM: So for your old house, copper is the way to go.
 
RICHARD: Yeah, there’s so much of it in place that you’re not going to replace it all with these plastic pipes but for new work you’re going to see a lot more plastic.
 
TOM: Speaking of copper pipes, have you ever seen the pinhole problem and how do you deal with it?
 
RICHARD: We have and there have been a series of reasons that it can happen. One is water chemistry in a town or municipality and the other is the velocity of the water going through the pipe and the other is electrolysis; you know, loose, stray voltage that can cause pit corrosion. And when it’s a problem, you have to go after it. You replace the piping as necessary.
 
TOM: Yeah. And you either have it or you don’t, right?
 
RICHARD: That’s right, which is (Tom laughs) – you feel lucky if you don’t have to. It’s awful.
 
TOM: Richard, Kevin, thanks for stopping by The Money Pit.
 
KEVIN: Glad to be here.
 
TOM: Great tips.
 
LESLIE: So I guess it’s safe to say that the old standards are still good choices but don’t be afraid, guys, of the new generation of plumbing.
 
TOM: Absolutely.
 
Well, today’s This Old House segment is brought to you by Cub Cadet. Cub Cadet – you can’t get any better.