of the building mounting bracket of fig2 the side of the holes 2410 are illustrated in invisible lines the space identified with a typical measurement of 0 629 inches in one embodiment can vary depending on the desired width of a mating part that space actually receives a portion of a bracket for securing a vertical member to a building mounting bracket in that space for that reason it is preferred that the holes 2410 be countersunk so that head of bolts inserted through those holes 2410 lie flat with the inside surface of the bracket fig2 is a perspective view of the bracket for securing a vertical member to a building mounting bracket the holes 2610 are provided a lower portion of the mounting bracket and enables bolts to be utilized to secure the mounting bracket to the vertical member using the t track approach previously described note that the bracket used to connect to the mounting bracket can be mounted to the vertical member in two orientations as described more hereinafter there is an upper portion of the mounting bracket 2620 which slidably engages with the building mounting bracket previously described it is desirable that the thickness of the upper portion of the mounting bracket 2620 be thicker than that utilized in the portions which mount to the vertical member fig2 a and 27b illustrate two alternative ways of enhancing the thickness of the slideable portion 2620 of the bracket of fig2 to ensure a snug fit when that bracket.