A Liquid Natural Gas storage tank comprising an outer mechanical support structure providing a closed space housing a membrane wall of the LNG tank, characterized in that the membrane wall is constituted by at least the following constructional elements in order from the inner surface side of the outer mechanical support structure toward the interior storage space of the LNG storage tank: a first end of a wooden spacer element is attached to the inner surface of the mechanical support structure, while a second end opposite the first end is attached to a backside of a wooden wall element, wherein a double plated membrane element is attached or located adjacent to a front side opposite the backside of the wooden wall element, wherein an outer surface of the double plated membrane element is facing towards the interior of the storage space of the LNG tank, the double plated membrane element is constituted by a first steel plate being arranged with a first plurality of protruding corrugation elements, and a second steel plate arranged with a second plurality of protruding corrugation elements, wherein the first steel plate is welded to the second steel plate face to face, wherein top points or top surfaces of the first plurality of protruding corrugation elements of the first steel plate is touching corresponding top points or top surfaces of the second plurality of corrugation elements of the second steel plate, wherein the welding is done by spot welding together a selected number of touching top points or top surfaces of the first plurality of protruding corrugation elements of the first steel plate touching corresponding protruding corrugation elements of the second plurality of corrugation elements of the second steel plate, the membrane element is thereby arranged with an accessible space in between the respective first and second steel plates of a membrane element, a complete tank wall supported by the outer mechanical support structure is arranged by assembling a plurality of spacer elements supporting a plurality of continuously joined wooden wall elements supporting a plurality of continuously joined double plated membrane elements, thereby forming a closed leakage free storage space of the LNG tank. a first end of a wooden spacer element is attached to the inner surface of the mechanical support structure, while a second end opposite the first end is attached to a backside of a wooden wall element, wherein a double plated membrane element is attached or located adjacent to a front side opposite the backside of the wooden wall element, wherein an outer surface of the double plated membrane element is facing towards the interior of the storage space of the LNG tank, the double plated membrane element is constituted by a first steel plate being arranged with a first plurality of protruding corrugation elements, and a second steel plate arranged with a second plurality of protruding corrugation elements, wherein the first steel plate is welded to the second steel plate face to face, wherein top points or top surfaces of the first plurality of protruding corrugation elements of the first steel plate is touching corresponding top points or top surfaces of the second plurality of corrugation elements of the second steel plate, wherein the welding is done by spot welding together a selected number of touching top points or top surfaces of the first plurality of protruding corrugation elements of the first steel plate touching corresponding protruding corrugation elements of the second plurality of corrugation elements of the second steel plate, the membrane element is thereby arranged with an accessible space in between the respective first and second steel plates of a membrane element, a complete tank wall supported by the outer mechanical support structure is arranged by assembling a plurality of spacer elements supporting a plurality of continuously joined wooden wall elements supporting a plurality of continuously joined double plated membrane elements, thereby forming a closed leakage free storage space of the LNG tank.