Shelving widths are
measured end to end. When placed inside two uprights the overall
shelving section dimension will grow by approximately 5/8" on each side
inserted into an upright.
Therefore a 36" shelf can end up being 37 1/4"wide including the
thickness of two uprights. When sharing uprights to create side by side
units, add approximately 1 1/4" to the length to get your overall