Bigger Part 2

Building planetarium domes is a whole class of ideas, thoughts, challenges, frustrations, and dreams unto itself is it not? Google up 'domes' and there are people 'out there' (out there is a favorite phrase - out where? - my other favorite phrase is 'they make those' ... where exactly ARE 'they'??.. why they are OUT THERE, of course! ) - 'they' make domes of every description for every purpose. Rest areas - greenhouses - planetariums.

But for the home guy armed with stepladders, home depot tools (or lowes), and luckily for me, an old barn to hang things off of or at least to give moral support), vexing problems build as we get BIGGER. A central question seems to be - bottom up, or top down?

I've been top down so far. Ive built 9 and 15 foot domed theaters. But I couldnt make them water proof, so first I had to have a shed roof over the top. This had several advantages - keeping the rain out is huge, but it also gave a top support, allowing me to use light weight, bendable materials. But a guy with a stepladder can only build a shed so high.

So I begin to think, well it has to be built bottom up .. from the underside. But that goes against every roofing principle that says shingles have to overlap top down or the water wont run off! Then I read the geodesic crowd (bucky fuller) advocates top down, but you build the top on the ground and HOIST it up a mast, then build down.. Now THAT might work! the uppermost part is prebuilt, then suspended WAY UP THERE, and the lower regions (reachable by stepladder) are build around it in (hopefully) perfect symetry. Then the roof can be completed.

The center support post is removed once its self supporting.

This might work..