With the help another good friend in town (Doug, see last post), we were able to put up much of the siding for the tree house. Once we were organized the panel placement went up pretty easily. We used 3/8 textured hardboard that was pre-finished with exterior finish and has an exterior fake wood grain. I had to go back and re-nail some panels as I started with the wrong fastener (2" galvanized shake nails). I used 6d 2 inch galvanized nails.
Now, for the tweak...As I was getting ready for the work day on the tree house, I noticed a decided racking to the studded frame of the treehouse, probably because the frame was not fully braced before the winter weather set in. I did not shingle the roof because I want to finish stiffening the frame with plywood siding.
The solution! A cross brace to pull the frame back into square before the siding went on. Doug and I tried a simple pulley I had in the basement. No luck. The pulley just didn't have the muscle to tweak the house back into true. Doug thought for a minute and said "I remember a block and tackle in my garage.." He returned with a serious set-up set-up. Problem solved!
(although you should seen have tautness of the tackle line!...)