A sealed and thermally insulated tank for storage of a fluid, having a plurality of multilayer walls. A first of the walls has a secondary thermally insulating barrier including a first insulating panel along the intersection between the load-bearing structure of first wall and the load-bearing structure of an adjacent second wall. A second insulating panel is juxtaposed with the first insulating panel along one edge of the first panel opposing the second wall. The first wall has a secondary sealing membrane including a first corrugated metal sheet welded to a small metal plate of the first insulating panel; and a second corrugated metal sheet welded to the small metal plate of the second insulating panel. The first metal sheet and the second metal sheet are welded together via a joggled edge permitting the first and the second metal sheets to be lap welded to one another.