When are Pipes at Risk for Freezing and Bursting?

The freezing temperature of water is 32 degrees Fahrenheit. The pipes inside your home, however, are protected from exterior freezing temperatures through your home’s insulation so on days where it is 32 degrees outside, it does not necessarily mean that your pipes will freeze. Typically, pipes begin to freeze when the outside temperature is at least 20 degrees Fahrenheit outside of the building that contains the pipes. 

WHAT ARE THE CAUSES OF A BURST PIPE

For a pipe to burst, there are five possible contributors that could lead to a leak. These factors lead to either a gradual weakening of the pipe that leads to a small leak or a buildup of pressure that causes it to burst.

These are five of the several reasons for a burst or leaking pipe:

• EXPOSED FREEZING PIPES
• HIGH WATER PRESSURE
• FOUNDATION SHIFTING
• AGING AND CORROSION
• TREE ROOTS 

EXPOSED FREEZING PIPES

During cold weather in the winter, pipes are exposed to the cold. When water freezes, it expands. The cold water crystallizes into ice, and the ice expands in the pipes. Pipes freeze when the water flow is too slow during extreme cold weather.
The main question when it comes to freezing pipes is: at what temperature do pipes freeze?
Pipes freeze when water freezes because it isn’t the actual pipe that is freezing; it’s the water. Year after year, as the water freezes and thaws, the cracks in the pipes grow larger until it becomes a leak.

HIGH WATER PRESSURE

High water pressure is likely to lead to the bursting of a pipe. Water causes erosion similar to how a river bank slowly erodes over the course of decades. Over time, the river cuts deeper and deeper into the side of the bank, especially when there is a curve in the river. When the river curves, the water forcibly beats against the turn and carries away rocks and debris. A similar thing happens with high water pressure in pipes.
Over time, the force of the water erodes the metal in the pipes, causing weak points to appear. Often, the weakest places are turns in the pipeage. When a pipe bursts from high water pressure, the pipe nearly explodes with water. The only way to stop it is by accessing the main shutoff valve and turning the water off. You won’t be able to use water until the pipe is fixed.

FOUNDATION SHIFTING

The second common reason for a busted pipe is a shift in the foundation. It’s unfortunate when a home is built on a shaky foundation, since a homeowner can’t prevent the earth from moving beneath the house. If the foundation of the house shifts, the pipes could bend and form cracks. 
25% of new U.S. homes will experience foundation distress. While that statistic is alarming, in the Midwest, the numbers are even higher. That’s because expansive soil (clay) is more prevalent in the Midwest. Clay soil expands and contracts greatly based on how much moisture it absorbs. In wet conditions, clay expands putting pressure on surrounding foundations. When the weather is dry, it contracts, leaving foundations unsupported. This back and forth causes foundations in clay soils to move much more than foundations built on more stable soil types. 

AGING AND CORROSION

Another factor that plays a role in pipe leaks is corrosion. Pipes are made of metal, and over time, metal corrodes. This mainly happens with older pipes in older buildings. Older plumbing pipes will have less building insulation, making the pipes more exposed. These exposed pipes are usually located in crawl spaces in older buildings. In the crawl spaces of a house, the pipes are left untouched and uncleaned for years. This type of damage builds on the general wear and tear of the pipes.

TREE ROOTS

When pipes are installed underground, they are safer from the elements, and they are out of the way for general construction. However, although the pipes are kept warm by the earth, they also face danger under the soil from tree roots. Trees and tree roots have the strength to push through cement sidewalks or grow through fences. Tree roots are able to mold themselves around things that are in their way. Tree roots won’t bother to change their course to avoid piping in the ground. The root can grow around the pipe and crush the metal or move the inflexible metal aside. This can cause major ground damage to the pipes and property damage to your land.

WHEN ARE PIPES IN DANGER OF FREEZING?

Water freezes at 32 degrees Fahrenheit. When water freezes, it expands, which is why cracks slowly form year after year in concrete sidewalks and asphalt roads. In the winter time, water seeps into microscopic gaps in the material. When the water freezes, the molecules expand just slightly. This forces the material apart, creating a crack. Every time the water is able to freeze and unfreeze, the cracks grow larger and larger until the roads and sidewalks are full of cracks and potholes.
A similar thing happens with pipes. When water is left in the pipes, the water is able to freeze and expand. This won’t necessarily cause a leak right away. However, if the pipes are already old and weak, it may cause a pipe burst. Typically, cracks from frozen pipes will happen over a period of time (usually over one winter if the pipes are constantly exposed to the freezing and melting of water).
However, just because the temperature outside is 32 degrees, doesn’t mean that your pipes are in danger of freezing. Most housing pipes are located inside the insulation of the walls. The insulation is meant to keep the pipes warmer than the outside temperature. You should begin to worry about your pipes freezing if:

• You are leaving the house for more than four days. If you are planning on leaving the home for an extended period of time, your pipes could be at risk. In this case, the temperature in the home would slowly drop to match the outside temperature as heat from inside slowly leaks outside. If the inside of the home is less than 50 degrees, the pipes could be in danger of freezing. If you need to leave a home in the winter (such as a winter cabin), set the thermostat in the home to 60 degrees.
• The pipes are exposed to the cold. If you have an unfinished basement with exposed pipes, the exposed pipes are in danger of freezing. Basements and garages are prone to freezing since they aren’t really a part of the home. They are typically exposed to cold temperatures since the heating systems won’t warm those areas.
• The outside temperature is lower than 20 degrees. If the outside temperature drops below 20 degrees, there’s a chance that your pipes could be at risk. Although the insulation of the home will keep the pipes reasonably warm, the walls are still able to absorb the cold air and expose the pipes to freezing temperatures.

HOW TO RESPOND TO A BURST PIPE

When a pipe bursts, the first thing you should do is find the shut off valves for the water. As soon as you find the valves, turn off the water to ensure that the water damage isn’t going to get worse. The shutoff valve will control the water in the entire house, meaning that you won’t be able to use water until the problem is fixed. If the pipe damage is severe, you might want to plan to stay at a hotel for a few days while the water pipes are reinstalled. If the damage is slight, the plumber might be able to fix the pipe quickly.