Leakiness is rarely a good sign in any situation. What’s even worse? That you may not know something is leaking, causing who knows how much costly damage. Turns out, half the homes in America have leaky ductwork. That’s no good! Improperly sealed ductwork can amount to an average loss of 20% of heating and cooling energy. That’s because many homes have flexible ductwork rather than sheet metal. It’s a lot cheaper and much easier to install but it deteriorates over time, as well as can tear and break apart causing that annoying and expensive leakage.