length of the cross bar of the h cross tie 8 so that the legs of each h cross tie 8 are received in the respective horizontal tie grooves 4 of the wall elements 1 furthermore the opposing wall elements 1 in the parallel rows must be placed so that they are directly opposed to one another so that the tie grooves 4 are directly across from each other this orientation enables the horizontal legs of the h cross ties 8 to be laid in position in the grooves 4 located at the ends of the top surface of the opposing wall elements 1 once the first course of wall elements 1 is in place in the two parallel rows the second course of inner and outer wall elements 1 is then placed in end to end abutting relationship on top of the first course of the two opposing parallel rows wall elements 1 it is customary as in conventional brick mortar wall construction to stagger the position of the wall elements 1 of the second course of wall elements 1 so that the end joints of the second course of wall elements 1 meet at about the midpoint of the wall elements 1 forming the underlying first course of wall elements 1 the bottom grooves 2 of the overlying second course of wall elements 1 fit precisely over the top ridges 3 of the first course of wall elements 1 to provide a snug fit which is capable of withstanding lateral pressure being placed upon the courses of wall elements 1 the tongue and groove arrangement complements the strength provided by the cross linking h cross ties 8 in the manner described successive courses of wall.