One Ring to Bind Them

The roof ring of a yurt is the least forgiving component to construct. The walls and roof poles need to be the right length and shaped and connected roughly as intended by the Mongolian geniuses who designed the yurt 2000 years ago, but my sense is that a few errors aren't likely to spoil the whole works. In fact part of the brilliance of the design is that the strength of the yurt isn't appreciably compromised by a few broken or missing roof rafters or wall slats. However, without a well-crafted roof ring in good repair, the yurt simply cannot be erected at all and your family will die from exposure to the harsh Mongolian winter. No wonder then that the roof ring is considered sacred and hence is treated with great respect. So naturally, it is with some trepidation and a great deal of care that I have been preparing my roof ring. Let's look at the steps to create the basic pieces (mostly pictured above) before assembly.

Today's featured 'yurt hero' is Mr. Matt. He is threatening to join me in the workshop for some hands on yurt-crafting, but so far it has been his prowess in materials procurement that has shined. Some weeks back I mentioned in passing to Matt that I was looking for a very large sheet of heavy card stock to make templates for the roof ring. A few hours later my phone rings and Matt reports that TWO large sheets of foam core board had been rescued on my behalf from certain dumping in the land fill.


Above you can see the template for a quarter section of the main roof ring drawn and cut out of one recycled convention booth poster. Two concentric circles are drawn on the board and then divided into equal quarters. It's handy to draw the whole 34" ring so after cutting out the template you can compare the template to the other three sections and verify it is exactly a quarter of the ring. Foam core, it turns out, makes exceedingly durable templates. The only caveat is that when using a craft knife to cut it out you are likely to make cuts at angles such that the bottom of the template isn't as accurate as the top face. But if you use the top side of the template when tracing your shapes onto the lumber, this need not be a problem.


It is easier to see the lines drawn on the board above, which lay out the template for the smaller, raised circle of the roof ring. My technique to draw circles was to attach thumb tacks to a large ruler. This allows easy control over the distance from the center to the edge of the circle being drawn. The pokey part of the tack penetrates the foam board and provides a solid anchor for the center of the circle. The other tack can then be swung around to etch out the circle in the paper surface of the board.

Once you've made all your templates, it's time to trace out your pieces in the lumber. In order to cut each section out of a single piece of wood, I had to get some very wide timber. I'm using 2x12 kiln-dried Douglas Fir. You must use stable, seasoned wood for the crown -- which is a little harder to source than green wood in such a wide board. I originally estimated a 16' board would be sufficient for cutting all the sections I needed. However in practice the location of knots and warping at the ends of the board decreased the usable wood and I had to buy an additional 10' board. Fortunately they weren't too expensive. This whole roof crown would have cost a small fortune though if I used the recommended oak, maple or beech hard wood. You would probably also have to glue together narrower boards to make panels large enough in these woods -- making it more labor-intensive as well.


Laying out the sections in the lumber requires some creativity to avoid ugly knots, cracks, and other problems. I had originally planned to use a jigsaw for rough-cutting the sections out, but I was so unhappy with the results on my first try that I began a serious search for a band saw. The North Portland Tool Library has just about every tool I need to complete my project, but a band saw isn't a very practical item for folks to carry home and then return to the library at the end of the week. Fortunately, tapping into the local Burning Man community yielded a band saw fairly quickly. More on that adventure next time.