Winter Worsts: Frozen Pipes are No Fun

The cold, hard reality is that winter will soon descend onto the land in the Greater Charlottesville area. And the Virginia winters of late have been unpredictable, the weather shifting from benign to blizzardous in the blink of an eye. With winter approaching, anyone who owns property in Charlottesville should be thinking about their pipes. Most houses with pipes that freeze tend to be of new construction but older homes with little insulation have their share of frozen pipes as well.So we know that pipes freeze and burst because of the weather, at the simplest explanation. Ice forms along the pipe, expanding. Water is a generally incompressible substance and so when the ice starts to expand, pressure builds up in the pipes and this causes the pipes to rupture. It all has to do with increasing water pressure in a confined location. So we know we want to keep the water away from its freezing point. How do we do this?

You want to leave the pipe exposed to the warmth from inside the house, usually by placing the pipe in interior walls. If the pipe is in an exterior wall, builders should try to position it between a warm room and some insulation; it’s cooler than the room but still above freezing in most cases. You or your builder may have to resort to using heat trace on your pipes. Heat trace is a resistance heating tape that gets wrapped directly around the pipe. It’s pretty pricy and requires electricity, so if the storm that hits is so bad it cuts the power off, the trace won’t be of much use.

Then there’s always insulating the pipe. It’s something you always want to do, and tend to do to varying degrees based on how cold you expect your house to get. Prevent freezing by slowing conduction (cooling coming directly from the walls) and convection (cooling coming from the cold air). The “wind-chill effect” from the convection of cold air is usually mitigated if insulation is present. For most wintry climates, inexpensive foam insulation will suffice…although there is always the heat trace for extra protection. Insulated materials are rated by their “R-value”: resistance to heat flow. There’s also K-value, a measure of conductivity/inch of material. If you’re really looking to secure your pipes this winter, think about molded fiberglass insulation with a plastic outer wrapping.

There’s also a device called a water shut off valve that senses leaks and cuts off the water main when detected. There are also air chambers; if measured and distributed effectively along the length of the pipe, they can handle the elevated fluid pressure caused by freezing. The air chambers have a reservoir of highly compressible gas which creates a cushioning effect, counteracting the elevated water pressure that causes pipes to burst.

Pipe Materials

Pipes are made from many different materials, all of which have positive and negative attributes. Here’s our brief breakdown.

Copper: Copper is king of pipe material. It’s been used as the standard for piping in the U.S. for 80 years, and many of those pipes are still going strong today. Copper is a very good conductor, so it’s likely to benefit from warm interior conditions and any residual heat, but it can also get cold very quickly if exposed to cold air. Insulation can sometimes block the pipes from getting heat quickly, or if there are gaps in the length of insulation, the heat will flow to those cold areas. But the longevity of copper can’t be disputed. It’s also the most expensive option.

Pex: Crosslinked polyethylene is a pretty flexible material that usually runs from fixture to source in a single straight line. Since it’s so flexible, it has the potential to freeze and thaw without the pipes ever rupturing, making it a good choice for cold climates.

PVC: These are firm pipes, whose walls are thicker than copper. They are poor conductors, and so tend to be more resistant to fluxes in temperature, even with insulation flaws. They can definitely expand a bit with increased fluid pressure, but don’t have as much flex as pex (ha). Also, the colder it gets, the more brittle this material becomes, so it’s not bulletproof.

You know the old saying. “An ounce of prevention…”