Authentic Therma-Tru sills and sweeps effectively seal the door system's base against wind-driven rain, directing moisture away from the house. For added protection, the recommended sill pan prevents moisture from reaching the subfloor. The robust, all-composite substrate, resistant to moisture and insects, ensures a durable and rot-resistant stepping area. The composite cap and nosing, resistant to moisture and insects, are thick and colored throughout, offering a wood-like finish while preventing wear and decay. The high-dam, slim cap works with the dual-bulb sweep to deflect moisture, while the engineered U-shaped weather seal further guards against moisture ingress. The use of flush, premium stainless steel screws ensures a continuous seal, resisting corrosion and allowing vertical adjustment of the cap to preserve a snug fit. The thick, 15-gauge aluminum approach enhances durability and ensures a firm stepping surface.