This picture shows the start of construction for the new observatory.
The existing pier is fastened to a 18 inch diameter x 48 inch deep concrete post. The eight holes surrounding the pier show the location of future concrete posts that will support the observatory floor.
The post holes are 10 inches in diameter and have a depth of around 30 inches. This will anchor the posts below frost line for my location.
The concrete posts are done. The 8" tubes are filled with approximately 120 lbs of concrete each. Even though it does not look like it in this picture, the posts are level. In the center of each post is a 1/2" j-bolt that will be used to attach the wood floor framing to the concrete posts.
Now I can start framing the floor...
The floor framing is complete. The frame members are constructed of 2"x6" pressure-treated lumber. The two beams consist of doubled 2"x6" lumber. The framing is attached to the concrete posts with post base hardware that is fastened to the 1/2" j-bolts embedded in the concrete. All of the joists, which are 12" apart, are attached to the beams and outer joists with the appropriate metal hangers and fasteners. The floor frame is very strong and will support any observatory that I choose to place on it.
Installation of the floor boards is next!
Except for some minor trimming and rounding over the edges with a router, the observatory floor is complete. The floor consists of 5/4 " thick composite decking material that should stand up to the harsh climate here. All of the floor boards are screwed to the framing. Along the bottom of the framing, metal edging is attached. This helps keep out the larger critters that want to make a home in the area below the observatory floor. In the future, the soil will be re-graded around the observatory floor to create an "observatory hill".
There are two cuts across the floor boards in the center of the floor stretching for six board widths. The purpose of the cuts is to allow these boards to be easily removed for the installation of a taller pier.
After almost a year of planning, approvals and site preparation, the observatory finally arrives!
Can this be it?
The first day of construction. Here, the walls are already up! I am checking the alignment of the wheel track and can barely see over the wall. You can see through the doorway that the existing pier is too short.
As the shadows lengthen, the day is quickly coming to an end. The dome halves have been put together and the whole assembly has been placed on the walls. While light in weight, it took three of us to get the dome into its final position.
There are still a few pieces to put into place before the outside can be considered complete. I will be working into the night to button things up.
The outside is complete! Now the work on the inside can begin...