Backyard Astronomy

 

Observatory Construction

The original 8" pier (we enlarged it to 12" after the observatory was finished) is standing and construction has begun on the floor framing.

Four corner posts rest on concrete deck blocks that sit on top of the ground. Other blocks and posts were added later. Floor framing is 2"x6" pressure-treated lumber.

Observatory

The floor is complete. Four more posts and deck blocks were added, and the frame was covered with 5/8" plywood that was first liberally soaked with wood preservative. Vinyl flooring was cemented to the plywood.

Not visible in this photo is the floor framing. It consists of 2x6 joists on 16" centers supporting the plywood decking.

Observatory

Pressure-treated 2x4s on top of 2x6s form the extension tracks for the roof. One end of each track is attached to the observatory with a heavy-duty angle bracket and galvanized lag screws. The other end rests on a 4x4 post, cross-braced with the second support post.

Observatory

The roof frame was built on a concrete patio near the house, then carried to the observatory. Two people lifted it - sans wheels - onto the extension rails.

Observatory

The roof was supported on 2x4 blocks while the Ondura covering was applied, and the final design of the wheels and tracks was worked out. Later, we raised the roof (so to speak) and attached the wheels.

Observatory

Here is a detail of the roof wheels and track. The wheels are hard-rubber casters attached to the roof frame with galvanized lag bolts. An aluminum angle bracket, 1/8" thick, serves as a retainer to keep the wheels on the track. Even though the roof weighs several hundred pounds, it's easy to open and close by hand from inside the observatory.

Observatory

Our house is sided with Hardie Plank, so we used it on the observatory as well. Sheets of the concrete-composite siding are attached with stainless steel screws. Hardie Plank does not rot or burn, but it's very heavy and requires a diamond-tipped circular saw blade to cut.

Observatory


Updated April 15, 2014