Before laying out the 2-foot centers for the base blocks, we snapped a chalk line on the floor. Because the barn walls were so wavy, we let the brackets set the actual distance from the wall.
With the base blocks screwed to the floor for the front of the cover, strips of wood with a ripped bevel set the space between the brackets at the back against the wall. The base blocks then attach to the brackets from the front.
Stock 1x5 boards rest on the base blocks to create the cover face. Perpendicular lengths were glued and screwed together and the corner was installed as one piece.
To attach the face board of the covers to the base blocks, pocket screw holes were pre-drilled and the screws were driven using an extended bit with a right angle drill.
Blocks are glued and screwed to the top of the face board aligned directly over the base blocks. Butt blocks (visible in the foreground) join the lengths of board to complete the face.