Hi Mark,

I am currently working on rebuilding a large post mill which is fitted with a self supporting octagonal roof on a brick roundhouse and it is not permitted for the roof to lean on the centre post !

Octagonal buildings are not that common today and the main ones that can still be easily seen are probably smock windmills. These can have several storeys coming off 8 long continuous slanting posts sometimes arranged in iregular polygon fashion.

The ultimate octagonal building is the lantern at Ely Cathedral see Hewett - English Historic Carpentry page 160 -164. This has 50 foot high posts standing on a 30 foot radius.

You might also want to check out the carpentry on the Globe theatre which is a 20 sided polygon. I seem to recall that there was an article in Joiners Quarterly about this project and I believe also in Timber Framing. Check out the past issues. There is also a chapter on the construction of the Globe in the book Shakespeare's Globe Rebuilt (isbn 0-521-59988-1.

I am about to start work on an energy friendly timber framed house which will have 5 segments of a 16 sided regular polygon arranged in an arc to catch the sun's energy.

Why not post a sketch of your project on the website. Like Will I am struggling a little to visualise the concept.

Regards

Ken Hume
http:\\www.kfhume.freeserve.co.uk