This image illustrates what happens when a pipe full of water is left outside in the cold winter months. The picture shows a tear in an outside copper line caused by the expansion of water in freezing temperatures. Obviously, this Kempton Park owner had to replace the torn pipe when the weather warmed up.
But why do the tears occur in the first place? Here’s the science behind it. Water has hydrogen and oxygen compounds that constantly move around one another. This kinetic energy, or energy created by motion, is caused by the fluctuation between the hydrogen and the polar bonds within the water molecules. When water is frozen, the hydrogen and oxygen compounds in the water stop moving, then spread out and form a simple crystalline structure that we know better as ice.
Water will always enlarge when it becomes ice because as water compounds spread out, the expansion also occurs within the molecule. So, there you have it: if you leave a pipe full of water outside in the winter, the expansion caused by the freezing of the water will build up lots of energy until it rips the pipe in half and causes a leak. And while there’s no getting around the science, there is one simple step you can take to avoid your pipes from breaking: drain your outdoor pipes before they freeze.