flange 42 has a short flange 44 which is bent away from the face of top concealed portion 16 to form an entry for the reception of interlock flange 20 of the panel 14 which forms the next higher course of panels for an illustration of the method of fastening panel 10 to framing member 56 reference may be had to fig2 to secure panel 10 to framing member 56 a number of fasteners 60 are driven through slots 36 the heads 62 of fastener 60 are larger than the width of slots 36 so that panel 10 is fastened to framing member 56 fasteners 60 may be nails or similar fastening means because fasteners 60 may be overdriven and hold the concealed portion 16 of panel 10 so tightly against framing member 56 there may be no movement of panel 10 along its upper area to compensate for expansion or contraction because of temperature changes to compensate for this deficiency and to ameliorate the effects of expansion or contraction of panel 10 thin strips 54 are provided to act as vertical stress relief means or isolation means to isolate the fastening function of fasteners 60 from the main portion 14 of panel 10 reference may be had to fig3 which is an enlarged fragmentary elevational view of the nailing slot 36 and the isolation means a series of separated slots 50 and an elongated slot 50a are located near nailing slot 36 to form a u shaped isolation means surrounding the sides and bottom of nailing slot 36 the isolation means allows for expansion and contraction of the siding panel without distortion the uncut areas 54 lying between slots 50 form a part of the.