Stick system curtain wall leak problems are frequently caused by water entry at the splice joints of the curtain wall frame and failure of the internal metal joinery seals. Remedial solutions involving occupied buildings inevitably face the multiple constraints of existing construction and business operations not present during the original curtain wall construction. In most cases, even partial disassembly of the curtain wall for internal seal repairs is not feasible. Remedial solutions which must be executed from the exterior of the curtain wall often involve wet-applied or preformed sealant tape bridge joints. However, some of the more complex joints cannot be repaired effectively or economically with the conventional bridge joint. Fortunately, custom fabricated three-dimensional preformed sealant “boots” are becoming available to address these situations. This paper discusses the design considerations and the selective use of three-dimensional preformed “boots” in sealing complex joint geometry that would not be effective with the conventional two-dimensional bridge joint.