Abstract: A seal for sealing the space between the inner wall of a tank and a roof floating on a liquid product within the tank includes a plurality of partially overlapping barrier plates mounted along a rim of the floating roof so as to extend outwardly along a first portion of each plate and then downwardly along a second portion of each plate which is relatively flat and which forms a seal against the inner wall of the tank. A plurality of resilient tension springs, mounted in spaced-apart relation along the rim of the floating roof, extend outwardly and bias the seals formed by the second portions of the plates against the inner tank wall.