Next, cut your stock lumber. The size of lumber will depend on the dimensions of your fridge and cabinet. You'll need two pieces that form the sides and one piece for the top. Once cut to size, the boards should be flush to the front of your fridge when butted against the wall.
To find the length of your surface, combine the width of the refrigerator and cabinet, then add four to six inches. This will account for mitered edges and allow the fridge to properly ventilate. Once you have this measurement, cut the surface length to size with mitered corners on both ends. Next, measure the height of your fridge and add 1 inch to account for a mitered edge. Cut the board, with one side mitered to line up with the top surface piece. Repeat to create a second side board. You should now have three boards with mitered corners that fit together to form an upside-down U shape.
Once you've finished all your cuts, sand any rough edges and wipe free of sawdust with a tack cloth. Use a lint-free rag to stain all sides of your three cut boards, including the mitered edges. Let dry before continuing to build.