A joint seal system and method may include a seal and a band. The seal may be positioned between abutting flanges of two adjacent duct sections. A band may be positioned over the two flanges and the flange interface. The joint seal system and method may be configured to mitigate and/or eliminate leakage of pressure, flue gases, condensate, and/or any other fluid, gas, and/or vapor between abutting flanges of duct sections at a flange interface.