yurt needing repair

[yurtin in Canada]

Hello- I am new here - this is my first post. We recently bought an existing yurt with wood walls and a wood/asphalt roof. It had been left vacant for 20 years and not maintained at all. The shingles had failed and water has been coming in for years. Some of the floorboards have rotted and the sill plates and also the tops of the joists. Also, the original owners put up some walls which now appear to be supporting part of the roof as that half with walls is higher than the other half. I don't know exactly how our yurt was built and how the roof rafters are attached to the ring but they look like on the saggy side - they are separating from the ring. We wanted to remove the interior walls but are now wondering how to ensure the structure doesn't fall down! Does anyone have any advice for me? I have been trying to find an expert in the Ontario, Canada area. Thanks for your help!

Sue