Specialized seals designed for the unique structure of French doors prevent air and water infiltration. These barriers, typically made of rubber, foam, felt, or vinyl, are installed around the frame and between the two door panels. For example, compression seals expand when the doors close, creating a tight barrier, while V-shaped seals wedge into corresponding grooves to block drafts.
Effective sealing around French doors offers significant advantages, including improved energy efficiency by reducing heat loss or gain, enhanced sound insulation, and protection against moisture damage and pest intrusion. Historically, simple felt strips were commonly used. Modern materials and designs, however, provide substantially greater durability and performance, contributing to more comfortable and cost-effective indoor environments.