Systems and methods are provided for insulation and moisture drainage. One exemplary system comprises a liner. The liner covers a frame element of an aircraft. The liner includes a first waterproof lip that is attached to a first insulator and protrudes towards the frame element. The first waterproof lip and the first insulator form a first drainage channel for the frame element. A second waterproof lip is attached to a second insulator and protrudes towards the frame element. The second waterproof lip and the second insulator form a second drainage channel for the frame element. The first waterproof lip and the second waterproof lip each include a lengthwise fixation element that attaches the first waterproof lip to the second waterproof lip, sealing at least a portion of the lengthwise gap.