Step 6: Mount the deck
Make sure the L brackets are flush with the wall and grab your screws and drill again.
Screw four #8 x 5/8" into the L brackets and into the wall making sure not to over tighten. Drilling the top holes first on both sides and then the lower two. Briefly marvel at your leveled out mount.
Pick up your board and place it against the mount. Pressing the deck to the mount grab a pencil and mark on top of the wood where the truck mounting holes are.
Measure the exposed edge, finding the halfway point in its height and make another mark of the midpoint according to your other mount marks.
Drill into these new points, starting the holes before actually attaching the deck.
Place the deck against the mount doing your best to find the holes you have already started. By doing it this way, if you measured correctly you guarantee that the deck will hang level as well.
Drill the farthest outlying mount holes and then drill the other two interior mount holes.
And that's it, you're done. I mounted mine over my bed and I am confident it'll stay up there, or it'll fall on my face and that would be a stupid injury.