To increase flat panel display and/or electronic device manufacturing device throughput, a second load lock may be stacked on a first load lock.  Each load lock may include one or more load lock doors for sealing the load lock such that a vacuum may be formed inside the load lock.  Pressure gradients (e.g., atmospheric pressure outside a load lock and/or vacuum pressures within the load lock) may cause a top or bottom of a load lock to move and thus one or more walls of the load lock to move.  Movement of a load lock wall that includes a load lock door may cause friction between a sealing gasket, the load lock wall and the load lock door.  Such friction may cause the gasket to wear and generate particulates that create defects during flat panel display and/or electronic device manufacturing. 
Load locks may be designed with one or more walls, a top and/or a bottom of a large thickness such that the pressure induced movement of the walls that include sealing surfaces is reduced.  However, increasing the thickness of walls, a top and/or a bottom of a load lock requires extra material, and therefore, increases the cost and weight of the load lock.  Further, increasing the thickness of the top and/or bottom of one or more stacked load locks increases the pitch of the load locks, which increases the complexity and cost of a manufacturing facility which includes the stacked load locks by complicating and/or increasing the cost of transfer mechanisms that transfer substrates to and/or from the stacked load locks. 
Accordingly, improved methods and apparatus for sealing a chamber (e.g., a load lock) are desired.