Post base prep

My original plan was to use 5/8" wedge anchors pushed 3" into drilled holes to secure the post bases, but the slab, I discovered, was too thin at one spot.

So plan B is a regular little footing.

Three inches of concrete is relatively easy to break. A clean controlled break, however, takes some perforating and chipping (unless you have a diamond-tipped hole saw for concrete).

Again my little Hilti 6C was the perfect tool. It took just a few minutes to knock out a 8" hole.

Pulling dirt out was also easy with a post hole digger. I went down a nice 18" in an inverted cone shape for load spread.

Making the wooden box formwork was the time-consuming part, in comparison, due to the varying slope of the existing concrete surface.

1/2" plywood is one material that's stiff enough to hold wet concrete, yet easy to trim. I fastened the sides with 1/4" crown 3/4" long air-driven staples, though nails or brads would have also worked. They need to pull apart later. Getting a tight contact with the slab surface while leveling the tops took several runs on a belt sander.