A flexible seal, typically made of extruded or molded material, is installed around the perimeter of doors to prevent air and water infiltration, improve energy efficiency, and reduce noise transmission. These seals come in various profiles designed to fit different door and frame configurations.
Effective sealing against the elements contributes significantly to comfortable interior environments by minimizing drafts, preserving conditioned air, and protecting against moisture damage. This translates to lower energy costs and extended lifespan of building materials. Historically, simple felt or foam materials were used, but advancements in materials science have led to more durable and effective solutions, including synthetic rubber and thermoplastic elastomers, capable of withstanding a wider range of temperatures and environmental conditions.