used by placing in the initial position the joint edge 4 of the groove panel with the equalizing groove 42 on the locking element 10 fig3 a the inclined portion 36 of the locking element 10 then is not operative this technique thus makes it possible to lock the floor panels mechanically in all directions and by repeating the laying operations the whole floor can be laid without using any glue the invention is not restricted to the preferred embodiments described above and illustrated in the drawings but several variants and modifications thereof are conceivable within the scope of the appended claims the strip 6 can be divided into small sections covering the major part of the joint length further the thickness of the strip 6 may vary throughout its width all strips locking grooves locking elements and recesses are so dimensioned as to enable laying the floor panels with flat top sides in a manner to rest on the strip 6 in the joint if the floor panels consist of compact laminate and if silicone or any other sealing compound a rubber strip or any other sealing device is applied prior to laying between the flat projecting part of the strip 6 and the groove panel 2 and or in the recess 26 a moisture proof floor is obtained as appears from fig6 an underlay 46 e g of floor board foam or felt can be mounted on the underside of the panels during the manufacture thereof in one embodiment the underlay 45 covers the strip 6 up to the locking element 8 such that the.