[fred cook]

Went with this design. It took 2 1/2 yds of high strength concrete plus some #4 rebar. When the existing slab was cut open, it proved to be a full 4" thick except for a void where I needed to mount a lift post. The hole was dug so that the new pour would lock under the existing slab on all sides. So now, I have a monolithic base block that weighs approximately 6500 lbs and is held in place by the rest of the slab. The new base is approximately 11 1/2 feet wide by 5 1/2 feet front to rear. Once I get the anchors properly set, I don't think there will be any problems with the posts staying put! The original contractor picked up the labor cost and I paid for the concrete. Might be the best money I ever spent!