Once the temperature drops to 32 degrees water begins to freeze and at 20 degrees celsius your pipes begin to freeze. As ice expands and the pipe freezes, pressure is the main villain in this situation. The pressure of the pipe increasing quickly is what makes it burst
Did you know 50% of homes in the United States have mold in them at this very moment, is yours one of them? By preventing water damage you also prevent mold growth, with some small precautions you can save yourself hundreds of dollars, hours of your precious time, and avoid risking the health of your family.