After the rafters were raised and secured last Saturday, we moved on to attaching the purlins. These are the radial pieces between the rafters that will hold up the roofing material. In our case, these are fashioned from alder branches or saplings, with the bark left on, nailed to the rafters with about a 4-inch spaced between them so that there is room for the purlins on the adjacent sides to attach.
It was great to have a “ground crew” of people to hand up purlins of the rough size needed, but I learned that non-woodworkers may not have the same level of discernment about whether a purlin had enough girth to support the span or if the wood was unsound. My suggestion is to pre-select all your purlins so there’s not a question, but with everything else going on, I had merely collected a pile of straight branches and thin trunks to use and hadn’t had a chance to “edit” the stack.
With the family helping, we got three of the eight panels purlined, although I may go back and add more here and there where I am feeling more flex than I’d like. After everyone left, I continued the work alone. I quickly realized it’s tough by one’s self to nail both sides of a 9-foot purlin as well as go up and down to get materials. I dragooned—I mean, apprenticed—my oldest daughter to help. She was a little hesitant at first aobut the height, but soon got used to it. She had used a hammer a bit before, but never pounded so many 16d sinkers in her life. After a few dozen purlins, her accuracy and ergonomics got better, although she wore out pretty fast. We’ll work on her endurance…
I noticed as I went along that I gravitated to larger purlins, in the 2-12” – 3” diameter. These sizes required me to half lap them at the ends to allow a 2-1/2” nail to get some purchase. No fine woodworking here: just a quick crosscut to depth and then split the waste away with a hatchet tapped in from the end.
Ultimately, we got the whole roof purlined:
Next task: to add a cupola over the central hole. After all, it does no good to put on a roof but leave a big hole in the middle!