A
groin vault or
groined vault (also sometimes known as a
double barrel vault or
cross vault) is produced by the intersection at
right angles of two
barrel vaults. The word "groin" refers to the edge between the intersecting vaults. Sometimes the
arches of groin vaults are pointed instead of round. In comparison with a barrel vault, a groin vault provides good economies of material and labour. The
thrust is concentrated along the groins or
arrises (the four diagonal edges formed along the points where the barrel vaults intersect), so the vault need only be
abutted at its four corners.