This is the aspect of tile roofing that most homeowners don’t know until someone explains it — and it’s worth explaining clearly, because it affects every installation decision that follows. Tile does not waterproof your home. Tile sheds water, disperses impact energy, and manages the bulk of wind load — but it is not a watertight membrane. The system that actually keeps water out of your home is the underlayment installed beneath the tile. The tile protects the underlayment from UV degradation, physical damage, and direct weather exposure. The underlayment is what stops water. This distinction matters for a specific reason: tile roofs are often sold on the longevity of the tile — 40, 50 years — without equal attention to the underlayment, which has a shorter service life and will typically require replacement before the tile does. A tile roof with a degraded underlayment leaks, regardless of how sound the tile surface looks from the street. This is the most common failure mode in aging tile roofs on the Treasure Coast, and it’s entirely predictable and preventable. Rhino Roofs installs premium tile underlayment systems designed for the specific thermal and moisture demands of Florida coastal construction. Our standard installation includes a self-adhered secondary water barrier at the deck level — meeting Florida Building Code requirements for wind zone compliance and Wind Mitigation Form eligibility — topped with a high-grade tile underlayment selected for durability under the temperature cycling and UV exposure that accumulates under a Florida tile system over time. We discuss underlayment specification with every tile roofing homeowner because it’s the component that determines the actual service life of the system — and making the right choice there is as important as choosing the right tile.