side of fig4 there is shown a cross runner and on the right side of fig4 there is shown a ceiling board both are mounted in position in the same manner the overall length of the cross runner or ceiling board is greater than the distance between the edge of the right lower flange of runner 26 and the edge of the left lower flange of runner 28 a space exists between flange 26 and the existing ceiling and this space is approximately one inch one end of a cross runner or a ceiling board is inserted into this space this provides sufficient clearance for the other end of the cross runner or ceiling board to clear the edge of the horizontal flange of the adjacent main runner 28 once the edge of the lower flange of runner 28 is cleared the cross runner or ceiling board can be moved laterally left to right and the cross runner or ceiling board is positioned as shown in fig3 another embodiment of the invention is shown in fig5 unequal eize bottom flanges 33 34 are shown on runner 36 the total width of the two flangee is the same as the width of the flanges of runner 28 but the sizes of the flanges 33 34 are about 1 3 total width and 2 3 total width while runner 28 has equal width flanges the unequal flange width will permit the use.