14.5.17

Building the Octagon Pt.7 First two posts.

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Various contacts have kindly tried to warn me against making dangerous lifts. So I was looking for a simple way to avoid lifting the frame for a whole side of the octagon. That would not only be 4m high but 1.2m wide with three sturdy 2"x 6" cross braces/joists. The 4m [12'] lengths of 4"x 4" are pretty weighty! Doubling them up simply doubles the weight of course. Then it has to be lifted as a unit using props. I have decided it is best not to do it that way.

So it was back to using a pair of my folding stepladders all straightened out. Using suitable side braces they are quite capable of considerable stability thanks to the extended aluminium crossbars at top and bottom. They are lashed together at the top and then used as double height stepladders in their own right.  Reaching easily to 3m [10'] even with very gentle slopes. The bases dig into the soft sand&gravel

I have used this arrangement for all kinds of heavy lifting with a chain hoist hanging from the tops of the ladders. I added a single 2"x 6" ground brace for unquestioned stability and quickly raised the first two posts.

The vertical posts were each roped to the ladders at a suitable height to ensure they remained safely upright. The bottoms of the posts were set in the footing brackets and cycling toe straps clamped them in place. I then adjusted the ropes and ladder to bring the posts perfectly upright using a 4' builder's level.

The plan is to chop out the sockets for the joints before each of the posts is erected. The two lower braces will only be added once each pair is safely raised and secured with lashings to the ladders. The tops of the posts will then be securely braced with 4.5m long 1"x 4"s and cord while I move the pairs of ladders onto the next post. This way there are no tall unsupported frames swaying in the breeze. I can also work quite comfortably completely unaided.

The next image shows the two lower joists in place though rather hidden by the stepladders. Instead of cutting joist sockets with the router I have decided to use large nailing plates over the pairs of 4" screws.

The final ring of cross braces at the tops of the posts can be added once the ring of eight posts is completed. Horizontal cross joists and braces will be added for extra stability before I ascend to the tops with a heavy 2"x 6" brace and rechargeable drill between my teeth.

Click on any image for an enlargement.
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