What is the purpose of a deck drip edge and how does it contribute to the overall functionality and longevity of a deck?

A deck drip edge is a metal flashing installed along the edge of a deck to prevent water from seeping into the underlying structure. It helps redirect water away from the deck, preventing rot, mold, and decay. This contributes to the overall functionality and longevity of the deck by protecting it from water damage and extending its lifespan.