Insulated tank

In a metallic tank capable of storing or transporting large volumes of liquid at temperatures from about -70.degree. to -400.degree.F., said tank having a generally rectilinear cross section, wherein the internal surface of said tank is lined with a foamed insulation on at least the upstanding walls and the floor thereof, an improved corner joint construction between the wall insulation and the floor insulation comprising a layer of foam in the corner, abutting the wall insulation and the floor insulation and having a density of at least one pound per cubic foot greater than the wall and floor foam insulation and having incorporated in said denser foam an interlayer consisting of flexible webbing of generally retiform construction, said flexible webbing extending beyond said denser foam and incorporated into the abutting layers of lower-density foam affixed to the wall and floor of said tank.