relatively flat back 54a and a pair of laterally spaced apart legs 54b each clip is anchored to its strip 52 by nails screws or other suitable fasteners 56 which extend through the clip back 54a into strip 52 as best seen in fig5 the clip legs 54b lie parallel to the edges of the associated wood strip 52 being spaced somewhat inboard of those edges the upper edge margins of each clip leg 54b is turned inward and back on itself to form a lip or overhang 54c at the inboard surface of the leg about half way up thereon the spacing between the clip legs 54b is more or less the same as the space between the pairs of stringer tabs 46a 46b having oppositely directed noses 46c permitting the panel clips 54 to be clipped to those tab pairs as shown in fig5 when each panel 48 is engaged against the underside of stringer 44 and pushed upwards the resilient legs 54b of the clips attached to that panel spread apart to accommodate the tab noses 46c of the pair of tabs between them when the lips 54c on the clips clear those noses the clip legs snap together thereby interlocking the lips 54c and tab noses 46c to securely anchor the panel 48 to the stringer each panel is clipped along its length to the corresponding tab pair 46a 46b of a plurality of stringers therefore it is suspended in a horizontal plane furthermore the adjacent tab pairs are separated so that adjacent panels can be secured in the same fashion in spaced parallel relation to one another leaving a gap or recess 62 between them as best seen in fig4 thus this mode of locking panels.