Looking West

The pier is 18" diameter and 12' above the garage floor.  The column goes down through the floor into a 5'x5'x5' footing.  The column and footing are separated and isolated from the foundation wall and slab except at the very base of the footing down in the dirt.  The footing for the wall and the bottom of the pier footing are connected with rebar and concrete.

The column itself has an internal structure of rebar, including a spiral of rebar under the surface.  An 18" Sonotube was used as the form. It has been removed to reveal the concrete.  There are four bolts at the top that were bolted to a board then pressed into the wet concrete.

Pier through the framing

The house was built around the pier (not touching it, of coarse).

Platform ready for observatory

A platform was built on the garage structure with a one inch gap around the column. The garage roof and platform were then covered in a rubber product

The observatory arrives

The observatory comes as a very big box of parts  (600 pounds in an 8'x8'x8' cube).  The forklift had to be rented to get it out of the truck.  We then used the forklift to lift the whole box onto the garage.

The base is set

All caulking and fasteners are supplied with the observatory.  I secured the base with lag bolts through large washers.

Last wall about to go up

The walls go up as four separate sections.  There are some nasty gaps that require some significant backing and caulking.

My wife and helper

Two of us worked on the observatory assembly for about six hours.  We brought in two more helpers for the lift of the dome section itself.

All done

About an hour after completion, it began to rain hard.  It rained for a couple of days.  We found a couple of additional spots to caulk..