Sealed and thermally insulative tank placed in a supporting structure, including: secondary thermal insulation including a plurality of juxtaposed secondary insulation blocks on the supporting structure, a secondary seal including a plurality of sealed secondary metal plates disposed on the secondary insulation blocks and welded to each other, primary thermal insulation including a plurality of juxtaposed primary insulation blocks on the secondary seal, a primary seal including a plurality of sealed primary metal plates disposed on the primary insulation blocks and welded to each other, secondary mechanical coupling members (32, 41) extending through the secondary thermal insulation at the level of the edges of the secondary insulation blocks and holding the secondary insulation blocks in bearing engagement on the supporting structure, and primary mechanical coupling members (33, 42) extending through the primary thermal insulation at the level of the edges of the primary insulation blocks and holding the primary insulation blocks in bearing engagement on the secondary seal, wherein the primary metal plates, respectively the secondary metal plates, are disposed so that the edges of the metal plate are offset relative to the edges of the underlying primary insulation blocks, respectively secondary insulation blocks; characterized in that the primary metal plates, respectively the secondary metal plates, are held in bearing engagement on the primary insulation blocks, respectively the secondary insulation blocks, only by the primary mechanical coupling members (33, 42), respectively the second mechanical coupling members (32, 41), and in that the primary mechanical coupling members (33, 42), respectively the secondary mechanical coupling members (32, 41), are attached to the primary metal plates, respectively the secondary metal plates, at the level of attachment points (11, 24, 31) away from the edges of the primary metal plates, respectively the secondary metal plates. secondary thermal insulation including a plurality of juxtaposed secondary insulation blocks on the supporting structure, a secondary seal including a plurality of sealed secondary metal plates disposed on the secondary insulation blocks and welded to each other, primary thermal insulation including a plurality of juxtaposed primary insulation blocks on the secondary seal, a primary seal including a plurality of sealed primary metal plates disposed on the primary insulation blocks and welded to each other, secondary mechanical coupling members (32, 41) extending through the secondary thermal insulation at the level of the edges of the secondary insulation blocks and holding the secondary insulation blocks in bearing engagement on the supporting structure, and primary mechanical coupling members (33, 42) extending through the primary thermal insulation at the level of the edges of the primary insulation blocks and holding the primary insulation blocks in bearing engagement on the secondary seal, wherein the primary metal plates, respectively the secondary metal plates, are disposed so that the edges of the metal plate are offset relative to the edges of the underlying primary insulation blocks, respectively secondary insulation blocks; characterized in that the primary metal plates, respectively the secondary metal plates, are held in bearing engagement on the primary insulation blocks, respectively the secondary insulation blocks, only by the primary mechanical coupling members (33, 42), respectively the second mechanical coupling members (32, 41), and in that the primary mechanical coupling members (33, 42), respectively the secondary mechanical coupling members (32, 41), are attached to the primary metal plates, respectively the secondary metal plates, at the level of attachment points (11, 24, 31) away from the edges of the primary metal plates, respectively the secondary metal plates.