Making A Yurt Rafter Ring

One of the most basic components, yet one of the most crucial structural elements of any yurt is the rafter ring.  This device holds each rafter in place, ensures geometrical and structural integrity of the building, allows for installation of the essential dome vent and must be installed so as to apply uniform weight and pressure to each rafter at the same time that each rafter equally holds it in place.  There are a number of pieces that make up this assembly, whether it is designed and constructed  in-house or custom ordered.

The ring, in some instances, is built from one piece of wood.  However, this is quite a costly venture, relative to the total cost of the yurt.  Other wooden rings use a layered approach, sandwiching a layer of OSB between pieces of dimensional lumber, or the reverse. Other rings are constructed from metal, or metal and wood combinations, while a few are built of polymers.  Since most yurt-dwellers have a core of self-sufficiency, I recommend constructing the ring completely from dimensional lumber, in layers. 

For this piece of your modern Mongolian yurt, you will need fourteen eight-foot lengths of one by six spruce, fir or pine planks.  As well, one quart of carpenters glue and one hundred eighty two-inch construction screws complete your parts inventory.  For tools, you will need a variable speed drill, ½ inch drill bit, screwdriver bit, jig saw with blades and a small paint brush.

Begin by cutting all of the eight-foot lengths of planking into four-foot lengths.  Lay them side by side, using nine pieces on the first layer to form a near-square.  Due to the actual width of a six inch plank (5.5 inches) he total width should be 49.5 inches – slightly wider than the length.  At this point, this is not important.  Next, tie these boards together temporarily, using one of the four-foot lengths screwed across the centre point of the nine boards.  Apply a liberal coat of carpenters glue to the surface.

For the next layer, lay the second set of nine boards perpendicular to the first layer, with the leading edge flush with one side of the 49.5 inch width.  This will leave 1.5 inches of the first layer exposed.  Later, that surplus will be removed.  Put one screw at each end of the nine boards of the second layer.  Since there is no lateral security using single sets of screws, you now are able to square the assembly, using a standard two foot square.  Holding the setup in place, set one screw every six inches, alternating from one side of each board to the other.  The screws will protrude beyond the bottom side of the first layer at this time.

Flip the two layers over, applying a layer of carpenters glue to the underside of the first layer.  Lay the third layer of boards perpendicular to this first layer, and attach exactly as you did with the second layer.  Allow the assembly to dry, then use a saw to remove the 1.5 inches of excess width on the second layer.

Use two strings from alternate corners of the square, so that the two strings cross over precisely in the centre of the box.  Secure a nail here, then tie a string that is exactly the length of the distance between the centre and any side to the nail.  Be sure that the string or twine is not stretchy.  If necessary, use a thin piece of wire.  Hold a pencil at the very end of the string, and arc it around the outside of the square, drawing a perfect circle.  Now, shorten the string by eight inches, and draw a second circle.

Using your jig saw, cut the exterior run of the first circle.  Drill a hole at any point of the inner circle, then use your jigsaw o cut out the centre piece.  You have constructed your basic rafter ring.  However, for added reinforcement, you may want to screw a band of medium thickness aluminum ring around the circumference of the ring.  Alternatively, a ring of 3/16 inch plywood may be glued and screwed to the outer edge.

Yurt Drawbacks and Advantages

So you have looked at modern yurts, and are convinced that you would love to live in such a structure.  The salesman tells you all of the great things about the yurt (there are many), and you are more enthused than ever.  The price tag is presented, and you learn that yurts cost anywhere from one tenth to one fifth of a similarly sized bungalow. You are told that a yurt can be assembled within a couple of days.  So, knowing that you will be mortgage-free the instant that the home is erected, and you will be living in this space-age creation (that was first constructed several thousand years ago in the Slavic and Mongolian regions), you jump at the chance to go minimal with this unique idea.  But, there’s a lot more to be considered before you buy!

While yurts do hold great appeal, and while yurt living has a lot of advantages, there are myriad drawbacks, impediments and disadvantages to consider, as well as significant design and sizing options, depending on your region and geography.

Before we look at design considerations, reflect on a few of the more obscure issues that become very significant once you have moved in.  In our locale, for instance, we commune with nature in a very intimate way, with black bear, deer, raccoons & skunks, wolves & coyotes, weasel, mice, squirrels, an army of insects, garter snakes, birds and so on.  This interaction with nature is, for the most part, enjoyable. 

However, when the bear gets up close and personal, you don’t want to be cooking inside a flexible wall yurt, with plastic windows.  A solid wall yurt, raised off the ground is a must. 

When the skunks, weasels and squirrels take up residence under the building, there goes the neighbourhood.  Consequently, an effective mesh screen and lattice barrier is vital to keep the predators and vermin away.  Sure, the weasel will eradicate the mice, but that leaves the problem of a noxious weasel!  Skunks are fairly easily relocated, since they do not care to be in close proximity to us.  It is reciprocal.  Squirrels offer greater resistance and, like raccoons, can wreak havoc on the tarpaulins.  Our yurt integrates so well into its surroundings that a raccoon family has torn holes in the roof tarpaulin, merely by climbing onto it.  Squirrels leave only pin-sized holes, but more of them.

Birds are much more difficult to deal with. Their use of the yurt roof tarpaulin for target practice is a mere annoyance, but their clamouring across that same roof scratches the fabric as much as any squirrel.

Wolves are a great experience, while coyotes, after you have been away from the yurt for a week or so, do not hesitate to move in, burrowing little caves under shelters.

Insects, like mice, pose a major problem.  No yurt should have carpeting inside, because of the risk of ant, tick and spider infestations.  As tightly as you seal the walls and flooring, insects find entrances.  With flexible wall yurts, mice are a major issue.  This problem is eliminated with well-built solid wall designs.

Overall, though, the advantage of being in close contact with nature in your yurt outweighs the problems that such contact poses, if you prepare for these intruders and guests.  Because of the tent-like assembly, you are intimate with the outside world, hearing almost every sound.  As well, by using design and colour options (camouflage, etc.) for your tarps, the yurt may blend discretely into its environment.

The basic yurt design lends itself to several drawbacks. 

Flexible wall yurts, for instance, have walls that are less than two inches thick.  Even with the space-age bubble and foil insulation employed, you will experience more rapid heating and cooling variations inside this building.  However, a solid wall yurt can be constructed of conventional studding, and insulated to higher levels using fibreglass matt insulation as well as bubble & foil or Styrofoam foil combinations.  On the other hand, a yurt, because of its circular design and open concept, heats and cools much more effectively than a similarly sized bungalow.  For example, our 600 square-foot yurt can be heated during minus 25 temperatures with a small radiant propane heater (4-6,000 BTUs), and a 20 pound tank will last nearly a week.  A 600 square foot house would require triple that amount of fuel and still have cold and hot zones.

It is impossible to use standard glass windows in a flexible wall yurt.  Consequently, the norm is to install single-sheet heavy plastic windows, which transmit a great deal of the heat or cooling between interior and exterior.  A solid wall yurt, on the other hand, can accommodate standard window units (smaller sizes).  Doors pose similar issues, and, more so, because most yurt vertical walls are 6’6” to 7’ – less than standard door frame height.

Other infrastructure poses challenges, too. All wiring must be routed through conduit, as it is installed on the outside of the walls framing, rather than through it.  An option is to use low voltage wiring and inverters throughout the building.  Plumbing, too, is installed in plain view.  Of course, this method of installation is much easier and quicker. 

Due to the open design of these homes, privacy is impacted, and closet space is at a premium.  Creative layouts can offset these concerns.

Other considerations include safe heating systems.  Open flame is very risky in fabric yurts.  With solid wall designs, flame retarding materials and fire-rated wall boards can be installed.  Yurts may be purchased with mounting for chimney egress, but pay close attention to sparks that may burn through the roof tarpaulin!

Other problems that may arise include condensation issues in cold weather, when warm, moist air rises and contacts the thinly insulated ceiling materials, condensing and falling inside the building.  If tarpaulins (particularly roof tarpaulins) are not skin-tight, wind causes the tarp to billow which, in turn, packs down any matt insulation used and reduces that R-value. While the wind effect against a yurt is minimized because of the round design, this means that there are no leeward sides or areas next to the yurt, where you can huddle against the cool breeze.  That also allows smoke and loose sparks to migrate around the building during the winter.

Yurts, almost always, do not meet zoning demands of any urban jurisdiction, and, therefore, do not qualify for permits.  If you are building in remote locations, this will not be an issue, and some solid-wall designs, indeed, can obtain engineer certification.  Proper design and construction practices should be employed regardless of whether the building meets code.

Most of us choose yurts as our living option because of its simplicity and eco-friendliness.  Simplicity equates to Spartan, and Spartan means less luxury.  The yurt is simple.  That, in turn, should eliminate the expectation of opulence.  If you want opulence, stay in the city!  The yurt offers a wonderful escape and alternative to conventional housing, but be prepared for the drawbacks, as well as the advantages.

Yurt Trusses Withstand Heavy Snow

One of the concerns that we had when we constructed our yurt was that the winter snow load might be too stressful for the design if the roof. In our part of the continent, we get a fair amount of snow and lake effect snow (120 cm per winter, or 47.5 inches). While this is less than the mountainous areas or the eastern seaboard often gets, our snow stays from November until late April.
The roof trusses are designed with two-by-fours installed 24 inches on centre at the wall top plate, merging to 1.5 inches at the apex of the yurt dome. Most of the conventional, commercial yurts have a similar truss distribution, and claim that they are sufficiently solid to withstand normal snow loads. However, those manufacturers also offer wind and heavy snow load reinforcement options. Our design has an additional drawback: it is designed with a 28 degree slope, instead of the 40-45 degree slope that is needed to ensure that snow slides off the roof.
In order to distribute the weight of the snow, we installed collar ties at the seven-foot point on each truss (our yurt has a 28-foot diameter), with hurricane ties at the wall plates. To ensure lateral and diagonal stability, we used a 3/8 inch aircraft cable, adjustable through use of a turnbuckle, looped through the ends of each truss. Three by six inch reinforcing plates are affixed within two inches of the top and bottom of each joined wall section.
During the fierce winds that we encountered in late October, there was absolutely no movement of the yurt, providing us with some sense of security that the structure was sound. However, lateral wind is not comparable to vertical pressure of weight, so we have had to wait until the snow arrived to test our design.
As of January 26, we have received 10 centimetres more than the entire seasonal average of snow for our area, so measuring the impact of the snow load for a typical season is possible.
Not only has the roof assembly withstood the entire load, but it has not sagged more than 1 centimetre (1/2 inch), yet the snow depth is almost 8 inches on the lower third of the roof. To further test the strength and stability of the trusses, I climbed on the roof and put my entire weight on the mid-point between collar tie and wall plates, and collar tie and dome. No sag was noticed.
Given the additional reinforcing measures that we incorporated into the design, this durability is to be expected. However, it is welcome to see that theory and practice meet, when it comes to the strength of our design. Consequently, I have no hesitation in recommending a similar layout if you are contemplating construction of your own yurt.

Yurt Wall & Roof Preparation

Once the walls of our yurt and the roof rafters were in place, there was a strong urge to apply the tarpaulins, just so we could see the “finished” product. However, several preliminary steps were required, to ensure that the treated fabric would last, that the building was wind- and rain-proof, and that the structural integrity was intact.
Hurricane ties were installed on the outer end of each rafter, in addition to the two screws holding the rafter ends in place. Although wind resistance is minimized with the circular design, screws are insufficient to provide the strength needed, as screws have a tendency to shear. In fact, in most jurisdictions, screws are not acceptable, according to the Building Code, for framing.
Hurricane ties were also installed on the roof ring end of the rafters, as a secondary support for the six-inch bolts securing each inner rafter end.
To reduce lateral sway, crossties were installed, earlier, at approximately the midway point of each rafter (see prior blog posts).
Where screws extruded from each plate joining the two-foot wall segments, the ends of the screws were treated with latex caulk, to reduce rub friction against the inner layer of tarpaulin.
At the top edge of the roof ring, we fastened a rubber edging, to prevent rubbing of the tarpaulin against the sharp edge of the ring. We used a rubber molding from an old automobile windshield, fastened with roofing nails to the ring.
Lastly, an inner layer of tarpaulin was secured around the perimeter and on the roof of the yurt. These tarpaulins provide an additional rain and barrier, but, more importantly, act as a buffer between the final, outer tarpaulin layer and the framing. The tarps cost less than $90 each, and should extend the life of the outer tarpaulin by 3-5 years (a cost saving of more than $1,600).
Just as in conventional buildings, caulk was applied around the windows and door, and drip mold & j-channel framed the openings.
One additional feature that we incorporated into the design was a roof-top vent system, to improve air flow. This vent was constructed (see picture) of osb, and oriented in a north/south direction, so that the vent windows can be opened on either (or both) end(s) to maximize ventilation.
In our next post, we will discuss finishing touches and exterior tarpaulin application. The following article will provide information on interior finishing stages. The last three articles will provide information on setting up our solar, wind & biomass energy systems, as well as our grey water recovery systems.
Should you desire a complete material list, contact me at bizdynamics1@gmail.com.

Assembling the Yurt Walls

There is the easy way to build a yurt: seek out a quality supplier of yurt kits, select your options &size, and then make your purchase. There is a more difficult way to build a yurt: tour the yurt demonstrations of a variety of suppliers and build based on those model units. Then there is the road less travelled: design & build your own. This is the option my wife and I have chosen.
Conventional, commercial yurt walls are constructed using lattice wrapped with pvc tarpaulin material. A thin aircraft cable is interlaced in the top openings of the latticework, and tightened using a turnbuckle. This structure holds the walls inward in a circle, while the weight of the rafters resting on the cable pushes the walls outward. Stasis, strength and stability thus are achieved.
Our wall structure begins with a 2*3 framework installed around the inside perimeter of a 24” by 84” piece of 7/16” thick oriented strand board. Since our yurt is twenty-eight feet in diameter, with a circumference of approximately eighty-eight feet, 44 sections are needed. Each section meets the next at an eight degree angle, requiring that one of the two vertical 2” by 3” studs is cut with an eight degree taper.
To lay out the bottom plate, forty-four 2-foot lengths of 2 by 3 are cut in a slight “vee” shape, at an eight degree angle, as well. Each wall segment will meet the next at the point of the “vee,” with a one-foot extension extending into the adjacent section base. By fastening the wall to these bottom plate segments, a solid circular frame is created.
As each section is placed standing adjoining the next, a top plate, identical to the bottom plate segment, is secured along the top 2” by 3” horizontal piece of the wall.
After making sure that all wall segments are vertically plumb, metal joining plates are fastened to join the segments at the top and bottom of each wall segment.
Next, windows and the main door are framed in place, in the same manner as a conventional wall and door or window buck are installed.
For our yurt, we purchased the 7’6” high by 94’ long tarpaulin from a New Brunswick supplier. The fabric intentionally was ordered longer than the actual circumference of the yurt, to allow for gathering and darts around the doors and windows.
Prior to installing the tarpaulin around the perimeter, window and door edges are caulked and sealed. Along the bottom of the wall segments, a strip of Velcro is fastened. The tarpaulin will extend one inch below the bottom of the wall, so that water will run off and away from the floor. After wrapping the tarp around the yurt walls and temporarily holding it in place, six 15-foot long ratchet tie-downs are connected and tightened along the upper perimeter of the walls, permanently fixing the wall tarp into place.
Walls are now complete.
The next article will describe how to construct the roof rafters and install the assembly onto the yurt.

Weather Wrecks Yurt Plans

Designing, constructing and living in my yurt was supposed to free me from more mundane housing concerns, cut costs, and make life more simple. Ha!
Since beginning construction on my own yurt design, I have been slapped with an important lesson: Nature rules. In our region – a normally dry, stable area in western Canada, late spring should be an ideal time to build. But record rainfall has flooded three of four western provinces, and, in our case, washed out access roads, and so severely restricted access that I have been forced to bring building supplies strapped to my back! We, fortunately, have had two days when we were able to work a supply truck across a neighbouring farm field. So, construction, severely delayed, still has moved forward.
Today, we are working on erecting the wall shells, with the roof rafters scheduled for tomorrow. Today, we will be working in thunderstorms, while tomorrow we will be working in humid, sticky heat.
Throughout this preliminary period, I have picked a total of 396 wood ticks off my legs, arms, back, scalp, etc. It is a record of which I am perversely proud! But, with the tick count cropping, the flood waters receding and the humidity & heat rising, a new nemesis has crashed the party: mosquitoes.
In the mid 1990s, Pioneer Quest tracked a year in the lives of 2 modern pioneer couples, who were required to build a cabin, break the land, and live precisely as pioneers in the area did in the 1800s. Those couples were inundated with natural disasters that year: excessive rainfall, exceptional summer heat, wicked mosquitoes and high snowfall & cold temperatures in the winter. It looks like we are on track to enjoy that same wonderful blast of nature. So must for minimalism!
Later this week, I will be providing details on the yurt design we have chosen, and the source of supplies. As construction progresses, I will provide photos and details, so that you can follow in our footsteps. Bring an umbrella and lots of mosquito repellent!

Regulations Stand in Way of Yurt Independence

Attempting to try to live life a little differently from the “norm” is a lot like trying to outrun Usain Bolt while he is running the 100 yard dash and you are doing the hurdles. It is more than a challenge; it is a nightmare.
Lucky for us, when we began to plan the building of our yurt, we were aware of the myriad of building code, zoning and environmental issues that we had to overcome.
First, the building code. Although the universal building code is intended to provide a consistent standard of construction across Canada (and the USA), each jurisdiction is empowered to tinker with its specifics. In cities, of course, there is a need for consistency, to protect neighbours, to ensure fire risks are minimized and to protect future occupants of a home or building. Yet, each geographical area has its own challenges, so supplementary regulations are enacted. To a lesser degree, in rural settings, these standards are upheld.
However, the plethora of farm buildings that are constructed to meet unique needs – hay barns, cattle calving pens, machine sheds, etc. are hardly likely to become homes for families, so standards for outbuildings are less stringent. Many rural authorities turn a blind eye to poorly constructed shelters and outbuildings.
Nonetheless, innovative structures such as straw houses, bermed buildings and alternative design concepts are rejected by community planners. In fact, such a simple variation on a basement such as construction with pressure-treated lumber instead of concrete requires an engineer’s stamp of approval.
Many authorities also require adherence (justifiably so!) to environmental regulations. Waste disposal is just one of these concerns. However, even the height of a wind turbine is regulated. Over a specific height will require an environmental site assessment, a permit, and appropriate lighting to warn off low-flying aircraft. This regulation is enforced, even in extremely remote environments, where many of the trees or geographical features exceed the height requirements for permitting.
We have made several concessions to our local authorities regarding construction standards. However, our design may still violate legal requirements. For instance, our interior walls are not fire-rated to the minimum one hour. It’s hard to fire-rate a tarpaulin structure for that period! We have no holding tank. Not much need when we anaerobically digest our effluent, and use composting toilets. We do not have concrete piles to anchor our structure. It is overkill to anchor a structure that weighs about the same as a half-ton truck. Our bedroom does not have a regulation-sized escape window. On the other hand, our bedroom has no walls, and the rest of the yurt has four windows and a door. We have no electrical network that is inspected. Truth is, we have only a 12-volt power system with an inverter for some minor appliances, but a home does need wiring and plumbing, according to the building code.
So, we do not have a home. Our yurt is a “temporary” structure, like a workshop or barn, not intended to live within. At least, that is how our municipality sees it. I look forward to spending my retirement years living in my barn, thank you!