Had some road base delivered on Friday and formed up the pier footing hole, ended up about 750x750x750mm and the screwed wooden frame is screwed and secured to star pickets driven deep in the ground, so it won't move or lift during the concrete pour. I have designed the rebar cage and will construct a "cap" from wood, to go on top of the form work, with a 750mm length of forma-tube attached and that will allow a single pour monolithic pier and footing, you can see my previous (and very similar) support pier construction
here and
here.
Another load of road base is due and a bobcat is booked for 4 Jan to scrape a path up from the house and spread the road base over the whole site. I can then move the site shed from my current observatory, on the other side of Canberra, up to its new and 850m higher, home at Eagleview
I also positioned an alignment stake about 60m from the pier footing hole to facilitate true south alignment in the future. I used binoculars to sight the SCP (whose location I know with a high degree of accuracy) at night and traced up and down, moving the distant stake East and West until it lined up with the SCP and the stake in the middle of the footing hole, easy. I am confident (err?..as long as no one moves the stake!
) this will allow me to point my bolt pattern and align my deck, with a +/- 1 deg pointing accuracy..maybe even better!?
Photos also
here
Mike