7.03.2021 10cm/4" short of a door!

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 Sunday 7th overcast with possible showers and/or sunny periods. I don't know where I found the strength but I moved the 2nd foundation block. To lie under the intended, door post on the right. I also sawed off the unwanted 2nd post to clear the doorway. Rain stopped play just as I finished backfilling the hole.

Meanwhile, I keep thinking about diagonal bracing for the frames. The cladding will provide serious triangulation by the "stressed skin" effect. I am questioning whether the entire building is suitably stiffened against distortion. Some 500kg of dome is going to be sitting on top.

What about bands of perforated, roofing strip? They could be used top, middle and bottom. To stop the building coming apart at the frame joints in a storm. Acting much like a traditional barrel or boarded, wooden silo. 

The new building has a 4' larger footprint but is no taller. It is more rounded than the octagon so should ignore high winds. Gusts should just flow around it and over the smooth dome.

If I were to clad the upstairs observatory walls inside, as well as outside. Again with 9mm grooved plywood. It would provide a seriously stiff and strong shell. To better support the dome rotation rollers on their laminated plywood ring. It would also be much more attractive inside. 

After lunch: I raised a double [door hinge] post and screwed it to the projecting timber above the intended door space. It was immediately obvious that I had lost a lot of potential door width. 

So I took one 2x4 away and left the other standing. Now I was back to 80cm door width but the post wasn't exactly upright. I will have to dig the foundation block up again. Then move it another 4" towards the shed. Which I was hoping to avoid because I hit a stone while digging the new hole. 

I could probably bolt the bottom of the door post to the outside of the brackets. That would gain me 2" or 50mm. Which is probably enough. The door post can easily be reinforced on the shed side to bring it up to size. I'll see how I feel about more digging tomorrow.  

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