I'm building a ger. You may know it as a yurt, or you may not know
it at all. It's a type of Mongolian tent, the design of which has not
changed for centuries. It's round, with no center pole, and withstands
the winds of the steppe like no other style of tent. I've written a
precis of my plans and procedures below.
Note: the author assumes the the reader has a basic knowledge
of shop safety and safe use of power tools, and accepts no responsibility
for any accidents that may occur to individuals using these plans.
making the rafters
start with: 30 furring strips
- Wrap the end of each furring strip with a couple of turns of filament
tape. This will keep the drill from blowing out the sides of the rafter.
- Drill pilot holes in the ends of each rafter using a 1/4" bit.
It helps to have someone telling you if you're holding the drill perpendicular
to the end of the rafter, but I managed to do it alone and only got
them slightly off on the angle. At least they're all consistently
- Squirt a dollop of Household Goop into the hole.
- Screw the decking screws into the hole, leaving about 4" sticking
out behind the head of the screw.
- Nip the heads of the screws off with the bolt cutters, and file
the sharp edges down.
- Paint or stain the rafters as you desire. N.B.: Latex paint does
not stick to filament tape. However, it does stick admirably to itself.
My rafters tend to stick together when they've been stored a while.
- This plan makes enough rafters to have one on every other top junction
of the khana and two on top of the door. You may want to have one
on every top joint, in which case you will have to adjust the details
of the toono accordingly, but that should be fairly self-explanatory.
You have rafters! What comes next?
making the toono
- Draw a 48" circle on the plywood and cut it out using the Rotozip
or a scroll saw.
- Measure 6" inside the outer circle, draw another circle, and
cut that out as well. You should now have a 48" outer diameter
flat wooden donut.
- Mark the edge of the roof ring every 5-2/5". (We arrived at
this number by dividing the outer circumference (150.72") by
28, the number of rafters we wanted to use.) With this mark as a center
point, cut notches 1.25" wide and about 1.5" deep. Your
roof ring will look like a giant cog.
- Next comes the tricky part. You have to build a small jig to help
you drill a hole in the center of each notch at a thirty degree angle.
Use scrap from the khana to build a small ramp for the drill to rest
on. Use a bit very slightly larger than the shaft of the decking screws;
they will insert into this hole. You must insert the drill at the
edge of the notch so it comes out the top of the roof ring.
- Place screw eyes about an inch back from the hole where it emerges
from the top of the roof ring. This will keep the pins from moving
left or right and twisting as they insert into the roof ring. Without
them you get a twist in the roof (the rafters look like they are spiraling).
You may want to add arches on top of your roof ring. Without them,
the smoke hole cover will lie flat across the hole in your roof
and collect water when it rains. We have not yet cut our smoke hole,
but you do have arches to keep the roof off of the pins. Without
them, the roof can be punctured by the pins. Puncturing isn't so
bad; it's the possibility that the canvas will tear that gives me
the willies. Our roof has already punctured, but did not tear; amazingly
enough, even through two thunderstorms at Pennsic, the roof did
not leak. Once we get the smoke hole cut, the punctures will be
a non-issue, as they will be cut away.
cutting the rafters
I'll write this portion when I've taken some measurements.
This does make a very large roof ring and a very large smoke hole.
You may want to make your ring smaller and your rafters longer. You
can figure this longer length using geometry (and you thought I was
kidding about the geometry textbook!), made somewhat easier by using
a roof pitch of 30°.