Each cleat will have 3 small boards connected like this.
Once I had all my braces built, I attached them to the wall. Every wall is different, but this is the method I have used on every floating shelf in my house.
These are the Spax screws I used to attach the braces to the wall. These are self-tapping and 3″ long. 3.5″ is a great length too.
I marked lines on the wall where I wanted my shelves to sit. I used a stud finder to mark my studs on the wall. These are the 2×4 that are under the sheetrock. Anytime you are mounting to the wall, it is best to try to screw into these studs for support. I used my Ryobi Impact driver to go through the braces and into the studs in the wall. Make sure to check for level so your shelf doesn’t sit wonky. This is the level I use… Cheap and works like a charm!
I attached the first two braces and it looked a bit like this…
I measured 13″ up from this brace to attach my next brace pieces using the same method.
Next, I basically wrapped the brace pieces. I started with the 1/4″ plywood for the bottoms of each shelf. I used my Ryobi AirStrike nailer to attach these bottom pieces into the braces using wood glue and 1.25″ finish nails. A stapler will also work on this part. I used my table saw to rip down the 1/4″ wood for this part, but you can also have Home Depot rip it down for you.
Now I attached my top 3/4″ boards. These are 1×10 common boards I found at Home Depot. I cut them to size using my miter saw, and attached them using wood glue and 1.25″ finish nails.