Abstract: Method and apparatus for relieving an elevated pressure behind a wall. The apparatus includes a rigid frame mountable over an orifice in the wall and a rigid panel sized to fit within the opening in the frame and to cover the orifice. The panel is mounted in the frame by a hinge which permits the panel to pivot with respect to the frame. The panel is also releasably secured to the frame so that when an elevated pressure is not present, the panel and frame are secured against fluid leakage. If an elevated pressure is developed behind the wall, the panel pivots with respect to the frame and thereby releases the elevated pressure.