Panelling method

A method of panelling a surface comprising the steps of providing a plurality of similar flat rectangular panels each with a contact adhesive on a rear surface thereof, adhesively affixing the panels to the surface in quadrilateral abutting relationship to define continuous linear vertical and horizontal seam lines therebetween, providing first and second groups of similar narrow elongated inner marginal members each having a contact adhesive on a rear surface thereof and a centrally disposed outwardly projecting rectangular tab at each end, dimensioning said tabs so that two end-to-end adjacent and aligned members of one group define opposing rectangular notches adapted to receive and substantially fit the tabs of two aligned members of the other group when said two members of said other group are placed in perpendicular relationship with the members of said one group, providing each of the tabs of at least one of said groups of members with centrally disposed locating means, affixing members of said one group to said panels with each member overlaying a seam between adjacent panels and with the locating means on its tabs aligned with the seam, affixing members of said other group to said panels with each member overlaying a perpendicular seam between adjacent tabs on members of said one group so as to be located and aligned with the seam, providing first and second groups of similar narrow elongated outer marginal members each having a contact adhesive on a rear surface and being slightly narrower than said inner marginal members, and affixing said outer members on and respectively centered and in alignment with said inner members to provide unitary stepped marginal members about all four sides of each panel.