The Octagonal Observatory

Walls Detail

The side panels are 14 pieces of shiplap nailed to two 47mmx47mm treated softwood posts.

The panels are made straight on one side and then planed straight on the other. The posts are attached to the base with metal angle brackets. This provides a good anchor but is not strong enough to hold the sides verticle. The rail will do this job.

One of the issues is the gap between the edges of the side panels. There are 3 solutions to this:

1. Place a verticle post on each corner and attach the panels to it. This would require removing the panels, resizing and replacing.
2. Attach a wooden batten (shaped) down the side. This is expensive, shaped battens cost £8 each. I could use a simple square one and plane it. This is the first option I'll try.
3. Put some form of flashing down the corners. Will work and be water proof but might look naff.

Alternative solution instead: I put "builders foam" in the cracks, lined the inside with damp course membrane. After cutting/sanding the foam it looks ok - and will look fine after painting it.