My architect messed up. The covered porch off of the second floor bedroom was drawn to have only one inch between the bottom of the sliding glass doors and the rubber roof material covering the floor of deck. The plans call for wood decking. The second floor is now built and my contractor just called this problem to my attention: There is not enough room to install a wood deck beneath the sliding glass door thresholds. Does anyone know of any material, suitable for a second floor covered deck, that can be installed at a depth of one inch?