A multiwall sheet comprises a sheet, comprising walls, wherein the walls comprise a first wall; a second wall; and an outermost rib extending between the first wall and the second wall, wherein the first wall extends longitudinally past the outermost rib to a first wall end and wherein the second wall extends longitudinally past the outermost rib to a second wall end; and an end cap comprising a top wall having a top wall end, a bottom wall having a bottom wall end, and a connecting wall disposed between the top wall end and the bottom wall end; wherein the end cap is disposed over the first wall end and the second wall end and wherein the top wall and the bottom wall extend longitudinally along the first wall and the second wall past the outermost rib.