How to Prevent Frozen Pipes

  • Transcript

    LESLIE: Well, frozen water pipes are a serious risk during very cold winter weather. And when water freezes in a pipe, it expands and then it can exert a pressure of over 2,000 pounds per square inch, which is enough to rupture pretty much any pipe that’s filled with water.

    TOM: Well, there are some very simple and inexpensive ways to prevent frozen pipes and we’re going to get those tips right now from a guy who has fixed more than his fair share of broken pipes, I’m sure. Not because he is an incredibly unlucky homeowner but because he is, in fact, the master plumber from TV’s This Old House, Richard Trethewey.

    Hi, Richard. Good to see you again.

    RICHARD: Hey, guys. Nice to be back.

    TOM: And I once saw a single, broken pipe dump over 5 feet of water in a basement. It was not pretty. So where do we begin to make sure we get something like this under control?

    RICHARD: Well, I’ve seen it all. You know, a split that’s about a ½-an-inch on a pipe, it can cause like $9,000; $10,000; $20,000 worth of damage.

    LESLIE: Wow.

    TOM: Wow.

    RICHARD: My own family’s house had a frozen pipe years ago and that water coming down through it, it was years before we got the house right again. The sad thing is it’s easy to prevent. So let’s just talk about how not to defrost them first. This is …

    TOM: Yeah, there’s a lot of bad ideas out there.

    RICHARD: Oh, my goodness. Don’t let anybody take a torch and try to thaw a frozen pipe. You just don’t know where that flame is going to go. Oftentimes the frozen pipe is where? Out in the outside wall or near the outside walls. So make sure you don’t do that.

    TOM: Right.

    RICHARD: The better way is to prevent it, OK?

    TOM: OK.

    RICHARD: Let’s seal all the holes and cracks around the home with expanding foam or some of that silicone caulk. I heard a quote once: “Think about a house as just a poorly-built boat.” And so, if it was – if you were in a boat and you had a hole that was letting the air in and there was water, in the case of the boat, look for the places you could sink. And so a small, ½-inch hole would be enough to sink any good boat.

    So you use foam-rubber pipe insulation. You’ve seen it at all the home centers. It’s usually 3/8 or ½-an-inch sidewall thickness.

    TOM: It’s like slit on the sides, right?

    RICHARD: That’s right. You can get it slit or not slit. The slit is the much easier one in a retrofit because you just peel the tape and bring it together.

    LESLIE: Slide it over.

    RICHARD: Yep.

    TOM: Right.

    RICHARD: So you want to peel that and then just put it together.

    Now, the elbows are where the freezing often happens. So we see people that just put the foam insulation on and then they leave the elbows exposed. What you really want to do is to cut a mitered corner to those – that foam insulation.

    TOM: OK.

    RICHARD: That would be done with a decent wood saw or a razor knife, just to make a nice, clean miter that can butt those two corners together.

    TOM: And then you tape them together with more of that foam insulating tape on top of that.

    RICHARD: That’s right. They have some special tape for it, so you can really make it tight. And that’s a homeowner, doable project. You know, you’re not going to really want a plumber to come in and do that and it could be a fun project, too.

    LESLIE: Mm-hmm. Well and in all of these instances that you’re mentioning, it’s in a case, especially in a kitchen, where you’ve got your sink that looks out a lovely window and you’re enjoying as you’re washing the dishes, so that’s a wall where there’s a concern.

    RICHARD: That’s right.

    LESLIE: But I’ve always thought, when you’re dealing with frozen pipes, it’s the exterior spigot that I need to make sure that I open up and turn off the supply from the house inside.

    RICHARD: Yeah, yeah.

    LESLIE: But I mean we really need to think about the entire house and its plumbing.

    RICHARD: Well, we see those kitchen pipes as the prime culprit because, oftentimes, you’ve run that hot and cold right behind the kitchen cabinets and it gets locked out. So if you’re going to try to thaw something like that, it should start by opening up the hot and cold faucets at the sink. And then you want to get in there with a hairdryer – never, never a torch – and you want to just start working it gently.

    It doesn’t need that much to break that frozen pipe but it certainly doesn’t need any torch, any flame.

    LESLIE: Mm-hmm. Now, is the symptom that the pipe is frozen, that you’re not getting any water? What if it’s a fixture you’re not using quite often and you don’t even realize that it’s frozen in that area?

    RICHARD: Yeah, you wouldn’t and then the scary thing that – a pipe can freeze in the middle of the coldest weather and you might not even know it until it thaws. And then, all heck …

    LESLIE: Water’s everywhere.

    RICHARD: Yeah, you really – yeah.

    TOM: Something interesting I learned years ago, that in terms of which pipe will freeze first, a hot-water pipe or a cold-water pipe, I’ve always heard that a hot-water pipe will freeze first because it’s got less air in it.

    RICHARD: I’ve repaired more hot-water leaks than cold-water leaks on pipes, yeah.

    TOM: Now, Richard, how does a pro – if they can’t get to the pipe – how does a pro actually unthaw pipes?

    RICHARD: We have a cool machine; a pipe-thawing machine. It looks like a glorified starter for your battery. It’s got two jumper-cable leads and you put one clamp on one side of the frozen pipe and another one over here and you turn it on and it actually melts the ice inside it. And that’s a lot safer than any other open flame.

    TOM: And a whole lot safer than a torch.

    LESLIE: Yeah.

    RICHARD: That’s right.

    TOM: Richard Trethewey from TV’s This Old House, thanks so much for stopping by The Money Pit.

    RICHARD: Glad to be here.

    TOM: And there’s a great video on, that will teach you how to prevent frozen pipes. Definitely worth checking out.

    LESLIE: That’s right. For more great, home improvement information, you can watch Richard and the entire This Old House team on This Old House and Ask This Old House on your local PBS station.

    TOM: And Ask This Old House is brought to you by the National Association of Realtors.

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