Build A Yurt Rafter Ring, Version Two

There are several designs of yurt rafter rings, each serving a particular purpose, and working best in specific environments.  Snow load, wind and even humidity play a role in determining the most appropriate design.  For the majority of yurt applications, the laminated design that I described in a previous article is the most effective.  However, the design described in his article is suitable for smaller yurts (less than 32 feet diameter) and in low humidity locations.  While it will withstand moderate snow loads, it is less structurally stable than the laminated version.

When designing a yurt roof, the same considerations that are factored into stressors on conventional housing roof rafter chords come into play.  That is, you need to consider the tensions (both lateral and gravitational) on the angled chords.  Truss chords endure two primary stress forces: the tendency of the bottom of the chord to push walls outward and the pull of gravity that causes slump in the riser chord.  Use of collar ties works to ameliorate the gravitational warping, but, simultaneously, actually increases the stress on the top plate-to-chord heel point of contact.  Fortunately, yurt roofs are so light that collar ties and webs usually are not needed. 

In my prototype solid-wall yurt, I employ several redundant reinforcements for the chords.  A series of mending plates, hurricane ties, aircraft cable and unique angled top plates create a structure that resists very significant outward stress.  These concepts will be presented in future articles.

The rafter ring design in this article consists of two layers of ½ or 5/8 inch oriented strand board (or plywood, if OSB is unavailable) and a collage of two-by-four blocks.  Other materials needed include a pound and a half of 3 ½ construction or deck screws, a pound of 1 ¾ inch construction screws, enough 3 ¼ inch framing nails to allow for four nails per block, and a quart of carpenters glue or three tubes of construction adhesive.

Begin by cutting a four by eight sheet of OSB into four-by-four pieces.  Scribe a circle four feet in diameter in the first piece, and a circle three inches smaller in the second.  These will form the upper and lower  layers of the “sandwich” ring. 

Cut as many four to six inch lengths of 2 by 4 as you will have truss chords.  Lay out the pieces around the perimeter of the larger OSB circle, equidistant apart, with the pieces pointing toward the exact centre of the ring.  Mark the location of each piece.  Apply a layer of carpenter’s glue to each piece, and re-secure them in the spots as marked.  Once they have dried sufficiently, turn the assembly over and secure the pieces using two 1 ¾ inch screws per block. 

Measure the distance between each block at the inner edge.  Cut pieces of 2 by four that will fit accurately between each 4-6 inch piece.  Do not worry too much about angling the cut edges precisely, as these pieces simply act as stabilizers for the main blocks.  Apply glue to the long edges of these blocks, slide them into place between each 4-6 inch block and secure them using 3 ¼ inch screws, toenail angled into place.  Use one nail per longer block to nail the spacers into place.

Turn the assembly over again, apply glue to the exposed edge of all of the blocks, and attach the second ring, with its centre aligning exactly with the centre of the larger ring.  Use two screws per block, as in the prior side of the sandwich.  Turn the assembly over once again, and screw in two screws per spacer block.

This rafter ring is much lighter than the laminated version described in prior articles, and is much easier to raise into place.  With the smaller ring on the lower side of this sandwich design, the truss chords, once cut on the proper angle, will slide into the notches quite easily and will hold themselves in place as each truss in installed.  However, the drawback to this design is the tendency for the OSB to expand and weaken if it gets wet, or for the screws to pull through if they are set too deep in the OSB.

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.

Building A Yurt In Winter

Building a yurt may not be at the top of your desirability rankings in the dead of winter, but, with proper planning, a quality structure can be pre-fabricated, then assembled on site in a matter of a few days.  While flexible-wall, tarpaulin yurts are the most popular structures in North America, it is the solid-wall yurt that provides the greatest protection, for the lowest cost in cooler and colder climates.  Soft-wall yurts offer the primary advantage of being able to be assembled, then disassembled and relocated with relat9ve we, while solid structures do not lend themselves well to relocation. The question then becomes, if you intend to relocate frequently, why not buy a tent or RV?

Our solid-wall yurt will stand for years, and has proven itself, already, to be a weather-tight, comfortable home.  Although, due to our wanderlust and travelling nature in winter, we do not spent the deepest Part of winter in our home, it has endured the coldest, snowiest and windiest days of our Manitoba, Canada winters.  If minus-40 is still too warm for you, then a yurt, of any variety, may not be a viable living solution! 

By using 2-foot panels, assembled on an 8-degree angle to each other, we have constructed a 600-square foot (that’s incorrect:  hard to have square feet in a round building!) facility.  Similarly, one could build a yurt in a variety of diameters (12, 16, 24, 32) with relative simplicity. 

Simply construct the individual panels, cut the sectional top and bottom plates, build the roof ring and saw the appropriate angles into the roof rafters, and the entire package of components is ready to be shipped to your building site.  Assembly on your pre-existing platform or floor should take two people no more than 12 hours.  Slide the wall tarpaulins around this wooden framework, slip the roof tarpaulin over the rafters and install your doors and windows and your yurt is ready for the finishing inside touches.

The tarpaulin walls offer both aesthetic and practical benefits.  As a Tyvek-type exterior skin, the tarp is impervious to the most violent winds, while repelling both rain and snow. The roof tarpaulin, however, needs to be installed tightly.  This demands that the supplier manufactures it to your precise dimensions and pitch, and that your roof rafters and top plate assembly are equally precise.  If the tarp is too loose, any flapping or vibration in the wind will act as a billows, and dislodge your roof fibreglass batt insulation, or break the seal on your foil-backed bubble insulation used to line the interior of the ceiling.

Within two days, your yurt metamorphoses from a pile of dimensional lumber and fabric in your garage to a fully liveable home, for less than 50% of the cost of a conventional  flexible-wall yurt, and one twelfth to 1/6 of the cost of s similarly-sized conventional house.  The added appeal is that this project can be undertaken and completed at any time of the year.

Yurt Interior Walls

One of the great benefits of the yurt design is the open room concept. The lack of walls means that air moves freely. Combined with the round yurt structure, this means that a greater efficiency in both air movement and its contingent heating efficiency result. However, modesty demands that we build our homes with a private bathroom. Even in a yurt, this means walls, and a barrier to smooth air flow. Similarly, many of us want closets and wardrobes, whether they are built as standalone units or integrated into the bed enclosure. Again, the natural flow in the yurt is interrupted by such barriers.
In our yurt, we built a six by eight foot bathroom, but left the ceiling area open. While the walls do provide impediment to air movement, the open ceiling concept means that warm, moist air is able to move out of the enclosure, and reduce heat and vapour pooling. By combining our closet space into the rear, outer edge of the bathroom, we were able to reduce the number of structural breaks.
Still, these barriers created condensation problems within the yurt. In the late fall, cooler outside air and a lack of air movement in the corner areas where wall met outside wall, a severe moisture problem resulted, with development of mould. We solved that issue by implementing several strategies.
First, we installed small 12 volt fans in these vulnerable portions of the yurt. The fans were salvaged from desktop computers, yet are sufficiently powerful to move the air away from these stagnant areas.
Next, we doubled up on the insulation factor where floor, outside wall and inside wall met, installing a one inch thick segment of polystyrene rigid insulation, extending six inches above and below the floor level.
The third change that we implemented was to install two fans along the top plates of the bathroom and closet, forcing air to move from floor to ceiling.
By moving our furniture and small items away from the outside wall, we increased air flow.
Lastly, we bored two inch holes at the base of the wall, allowing the air to move freely between the main yurt floor space and the bathroom and closet.
It is imperative, if you are choosing to build a yurt for efficiency, that you consider what makes the yurt an efficient design. Vertical air movement, allowing hot air to rise in the summer and vent at the apex of the dome, as well as moving it downward with small fans in the winter, is a significant feature of the yurt design. It is more imperative, though, that you reduce barriers to air flow in dead spaces and “corners” of the yurt. Simple layout alternatives provide this free flow of air. Where possible, consider moving walls a few inches from the outside, and tie them together in a free-standing box system, so that there is a space along the entire height of the exterior yurt wall, keeping air flowing freely. Ensure that insulation is installed properly and evenly, with no cold spots to encourage dead air and condensation.
Built properly, the yurt design is a marvellous system. Done carelessly, and it loses its structural integrity and natural efficiency.

Solid Versus Flexible Wall Yurt Systems

Yurt purists will insist adamantly that its simply is not a true yurt if it has solid walls. Yet, the original yurts, from Turkey to the Himalayas, had neither tarpaulin skins or space-age bubble insulation and glass-domed vents. Yurts, indeed, are more about simplicity and function than any purist concept of how they should be designed, and from what materials.
It is true that the lattice/tarpaulin skin systems employed by manufacturers from Yurtco to Colorado Yurts have aesthetic appeal. Their flexible framing, bubble insulation and heavy-duty pvc tarps allow for an intimacy with the surrounding environment that a conventional house or cabin does not. The sound of rain on the exterior skins is magical, and the thick plastic windows create an aura of living in a tent. Even in relatively stiff winds, these yurts hold steady, yet react to the breezes. Yet, these same benefits also can be drawbacks.
Since windows are nothing more than thick, clear poly plastic, they transmit heat and cold easily. To cut down on sun infiltration, the exterior skin must be zipped shut. Similarly, in winter, those same windows almost always are zipped closed, creating a claustrophobic, tomb-like atmosphere. If the window is improperly installed and allowed to vibrate or shake, the plastic quickly breaks down, and, in a matter of a few years, the window must be replaced when it cracks.
The light lattice framing does withstand winds of 70-90 kph, but a wind/snow load supplementary support system must be installed in high wind/high snow regions. Of particular concern for many is the loose fit of the yurt wall skins at the base of these units. While tight enough to hold back the elements, many yurts with lattice wall design, according to owners, allow small rodents such as voles to work their way into the building during the colder months.
Due to the thinness of the exterior walls, R-factor levels for insulation are minimal, with only a few centimetres of space-age bubble insulation protecting against the elements.
A reasonable fear that some people have expressed is that the light construction is a poor impediment to a hungry bear, who may smell food through the fragile skeleton of the yurt. Whether the fear has ever materialized is irrelevant, as the fear may still exist even where the risk is minimal.
On the other hand, solid-wall yurts offer a great many advantages. Few bears, badgers or raccoons have the tenacity to force their way through 7/16 inch of wood, plus framing, making the structure seem considerably safer from these predators than flexible-wall yurts.
With the exterior tarpaulin covering those walls, wind and air infiltration is minimal. The framing allows for two to three times the insulative capacity than lattice walls.
Wind endurance is significantly greater in a properly designed solid wall yurt, as well. Using the interlocking top and bottom plate segments that has been created for these units, the structures have endured winds of over 115kph, without any sign of stress or strain. In one instance, a healthy tree, sixteen inches in diameter, was sheared off by the wind not more than forty yards from the yurt, yet the yurt suffered absolutely no ill effects from the wind force.
Window and door installation is easier and less expensive in solid wall yurts. Because of their framing, these buildings can be constructed using standard windows (double or triple pane) and doors, allowing for reduced cost, energy saving and better light infiltration. It is also a lot more difficult for a raccoon to claw through a pvc & glass window than a plastic one!
Along with the advantages of solid wall construction, these hybrid yurts maintain the tarpaulin roof structure, along with added truss strength to withstand heavier snow loads. The tarpaulin skin allows for the same magical enjoyment of a rainfall on the tent-like roof, the same intimacy with the outside environment and the same open atmosphere as more “traditional” yurt systems.
Yurt purists may decry the bastardization of their beloved structures, but they will have a hard time denying the advantages of solid-wall over flexible-wall yurts.

The Romance Of Yurt Life, Wildlife Included

When you choose to live with nature in a yurt, it is a marriage: you accept the good with the bad. But even the bad can be great in the springtime! We have only been back in the yurt for a few weeks now, but our encounters with the wildlife have been nothing short of enthralling and amusing.
Last autumn, we closed out our season in the backwoods with a visit from a family of four raccoons, who systematically destroyed every bird feeder we had put up while they scavenged for the last meals of the season. A couple of squirrels determinedly decided to winter in the insulation under the platform deck of the yurt, as well, but we were willing to tolerate them for the four bitter months that we were away from our home.
As spring broke this year, though, we found just what damage a couple of active nut-eaters can do to insulation! Our raccoons have returned, as well. What is unusual is that the family of four remains together, with no new litter of kits in evidence. They announced their return by using their can-opener teeth to puncture a Coleman cooler that I had left outside. For dessert, they gnawed their way into a plastic gas canister, filled with mixed fuel for my chainsaw, and dragged the leaking container across the grass. Given their “finger” dexterity, I am glad I did not leave a barbeque lighter around!
Thirty miles north of us, Hecla Island, in Lake Winnipeg, is the summer home of turkey vultures and a few bald eagles. Rarely has either been spotted away from that area, yet, just as the snow melted from our meadow, a bald eagle pursued a mouse, and landed in the field to finish his lunch. It is just one example of the changing patterns of wildlife in the area. We have two mallard couples nesting in the creek bed not fifty yards from the yurt, sand hill cranes that have relocated their annual nesting area from the adjacent farmland to our small meadow, a grouse sitting on eggs under a three-foot high spruce in a clearing only paces from our home and coyotes that have decided that it is safe to howl, nightly, thirty feet away from where we sleep.
Late in the winter, I encountered a lone black wolf (probably from the Hecla pack) that obviously had strayed form its traditional range twenty-five miles north of us.
My wife is less happy with our annual migrant bear, who has, each spring and fall, travelled along our old riverbed with her latest cub. Two weeks ago, she came up to our doorstep with her cub, demolished a sealed garbage container and dragged one of the bags two hundred yards through our garden before tearing into it. As bold as that action was, she showed that she is less wary of human contact than ever, when she returned, during a rainstorm, to the yurt and rooted around the deck. In the morning, her huge paw prints in the wet clay where I had been excavating provided more than ample evidence of her visit.
Fortunately, our resident skunks and badger have not opted to become emboldened, and move in under the yurt platform!
More humorous that dangerous are the romantic interjections of local wildlife. Our ducks and Canada geese have almost finished their courting, calling, dancing and preening, while the frogs continue to be in great serenading voice. There is nothing quite so mood-destroying, though, as the cooing, gurgling and raucous clucking of crows in love. Their grating calls have all the appeal of a screaming baby. On the other hand, who can turn a deaf ear to the Buddy Rich drumming of a male ruffed grouse at 3:00 a.m?
The best of the strutting males though, has to be one of the many sapsuckers in the woods. For six years, he has chosen to drum his mating song not in nearby trees, but on any metal that he can find. Six years ago, it was my old Cockshutt tractor. Then, he found a better sound with an empty 45-gallon steel drum. Last year, it was the tin bonnet on my old camper. This morning, though, he reached the apex of quality music when he found that the roof of our new Prius provided the melody that he wanted.
It is there that I draw the line at passive interaction with nature. Tomorrow morning, I expect to join him with a few well-directed tennis balls to divert his attention from his new $30,000 toy! I expect, however, that, with the abundance of empty containers and old iron in the yard, it will be only moments before our rock-star drummer finds a new beat with which to lure his mate.

Inexpensive Yurt Flooring Solution

In keeping with the minimal philosophy of living in a yurt, the ideal design will employ a minimum of materials, be as “green” as possible and will be both sustainable and durable.
In our yurt, we have chosen a very inexpensive, basic design and material for our flooring. There are several reasons for this.
Firstly, cost is a factor in the decision as to the type of flooring to use. We opted for materials with a cost of less than $0.45 per square foot, plus $0.10 per square foot for finishes.
Secondly, we wanted to ensure that the frequent traffic directly from outdoors to indoors did not track in excess dirt. Carpeting would have trapped that dirt.
Thirdly, the location of the yurt in a wooded area would have attracted insects such as ants. By constructing flooring with a hard surface, we eliminated nesting sites for those insects.
Fourthly, we wanted a floor that would remain cool in the summer and able to adapt to winter conditions. With the hard surface, we were able to lay down area carpets that we already owned in strategic locations, while keeping bare floor at entrances and frequently used work areas, such as the kitchen areas and washroom.
Lastly, we wanted to minimize weight of the flooring, since we built the yurt on pads and posts, rasther than embedding pillars into the ground.
To accomplish all four goals, we used ¾ inch oriented strand board as sub floor material, with 1/8 inch good one side plywood laid at a ninety degree angles to the subfloor as the main floor. The plywood was screwed to the underlay using three quarter inch wood screws with threads the full length of the screw. The use of full-length threads is essential, so that the screws can be countersunk into the thin plywood.
Lastly, we used a clear varnish to coat the surface of the flooring, making sure to pay special attention to the high traffic areas.
Since installing this flooring, we have found that it works remarkably well, and shows a sheen and grain similar to good-quality hardwood or laminate flooring, at one quarter of the cost.
However, some problems have arisen. On occasion, we stored 20 pound propane tanks on the floor, and, with changing temperatures, the tanks attracted condensation. This condensation accumulated in a ring on the floor. To remove it, we lightly scoured the area with a Javex and water mix, with modest success. The only other problem has been a slight separation, due to the thinness of the material, in spots where insufficient screws were used.
This flooring has answered all five of our criteria for the design, and is recommended for anyone contemplating an inexpensive flooring alternative, whether in a yurt or cabin.

Yurt Perimeter Drainage Solves Humidity Problems

Perimeter drainage
Spring has proven to be a real test for our yurt. To close out the late fall and early winter, we experienced exceptionally unusual rainfall and early snowfall. Because we have built our yurt on the slope of a hill, the deck on which the yurt rests is at ground level at the rear, and fifty-four inches off the ground in the front. This permits good air flow, but demanded that we hoard the perimeter to block cold air infiltration. Unfortunately, the hoarding also trapped humidity, and we experienced numerous condensation issues throughout November and the first week of December.
The interior of the yurt is lined with foil-backed bubble insulation, with all joints taped. This makes for a very air-tight unit, but any moisture inside is trapped, as well. Cooking, showering and even everyday living contributes to the high humidity. We experimented with a number of options to reduce this wet air, with limited success.
The major problem was that, because it was winter, we needed to seal and insulate our rooftop vent. This creates a dome where the heat rises and remains somewhat trapped at the apex. Although the yurt is quite warm and well insulated, there are many partial thermal bridges, at the headers, the window framing and even at the roof ring and rafters. As soon as we reduced interior temperature, the cooler outside air would condense humidity on the foil, which would accrue and run down the walls or drip from points of the roof.
Using a fan at the peak of the dome ameliorated the problem, to a degree. Similarly, by adding insulation between the tarp and the exterior wall framing, we were able to reduce the temperature differential. Lastly, we reduced our interior temperature by a couple of degrees and maintained that temperature day and night.
The major problem that remained was the moisture in the soil under the yurt. This spring, moisture levels have been exacerbated by heavy rainfall and a slow thaw that releases the moisture in the ice slowly.
This week, we believe we resolved that issue. By trenching around the perimeter of the yurt profile to a depth of six inches and six inches wide, we have created a mini-drainage ditch. This U-shaped trench catches the rainfall as it falls from the walls, and directs it along the perimeter of the yurt, then away. There is no opportunity for the water to pool under the yurt and contribute to the humidity issue.
Although it is early in the experiment, it seems to be working. We have experienced no condensation issues in the first three days. Yesterday, the spring rains hit again, but there is no water under the yurt, and our humidity inside the yurt is no higher than the outside.
As we move through each of the initial seasons in our yurt, we have discovered new challenges and issues that would be uncommon in conventional housing. However, in spite of the spate of concerns, both of us are thrilled with this innovative living accommodation and its two overwhelming benefits: a miniscule cost (with no mortgage to pay) and its roomy in-touch-with-nature atmosphere.

Yurt Flooring

In keeping with the minimal philosophy of living in a yurt, the ideal design will employ a minimum of materials, be as “green” as possible and will be both sustainable and durable.
In our yurt, we have chosen a very inexpensive, basic design and material for our flooring. There are several reasons for this.
Firstly, cost is a factor in the decision as to the type of flooring to use. We opted for materials with a cost of less than $0.45 per square foot, plus $0.10 per square foot for finishes.
Secondly, we wanted to ensure that the frequent traffic directly from outdoors to indoors did not track in excess dirt. Carpeting would have trapped that dirt.
Thirdly, the location of the yurt in a wooded area would have attracted insects such as ants. By constructing flooring with a hard surface, we eliminated nesting sites for those insects.
Fourthly, we wanted a floor that would remain cool in the summer and able to adapt to winter conditions. With the hard surface, we were able to lay down area carpets that we already owned in strategic locations, while keeping bare floor at entrances and frequently used work areas, such as the kitchen areas and washroom.
Lastly, we wanted to minimize weight of the flooring, since we built the yurt on pads and posts, rasther than embedding pillars into the ground.
To accomplish all four goals, we used ¾ inch oriented strand board as sub floor material, with 1/8 inch good one side plywood laid at a ninety degree angles to the subfloor as the main floor. The plywood was screwed to the underlay using three quarter inch wood screws with threads the full length of the screw. The use of full-length threads is essential, so that the screws can be countersunk into the thin plywood.
Lastly, we used a clear varnish to coat the surface of the flooring, making sure to pay special attention to the high traffic areas.
Since installing this flooring, we have found that it works remarkably well, and shows a sheen and grain similar to good-quality hardwood or laminate flooring, at one quarter of the cost.
However, some problems have arisen. On occasion, we stored 20 pound propane tanks on the floor, and, with changing temperatures, the tanks attracted condensation. This condensation accumulated in a ring on the floor. To remove it, we lightly scoured the area with a Javex and water mix, with modest success. The only other problem has been a slight separation, due to the thinness of the material, in spots where insufficient screws were used.
This flooring has answered all five of our criteria for the design, and is recommended for anyone contemplating an inexpensive flooring alternative, whether in a yurt or cabin.

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 Totem Poles Stand for Family & Friends

We have a pole in the centre of our yurt. More correctly, we have two poles. Before you judge too harshly, these poles are neither dancing poles, nor firemen’s poles. They are prospective totem poles.
If moving from a middle-class home in suburbia to a Mongolian tent in the backwoods of Manitoba was not sufficiently unusual, we have incorporated a more clearly defined oddity in the living area of our yurt. Two spruce poles, crowned by a cross-member pole and crowned with a spiral of collar ties for the free-span truss boards, form our tribute to the iconic Pacific First Nations artefacts.
Granted, our future totems are significantly smaller than the mammoth totems along the Pacific Northwest coast. At an average diameter of 8 inches, they are paltry in size. They were also redundant in the yurt structure, as the roof assembly had sufficient strength without the addition of the centre posts and collar ties.
These totem poles, though, have a much more social purpose. On a counter adjacent to the poles we have an assortment of carving chisels and shaping knives. At our official “yurt-warming” party, scheduled for later this year, we will launch the first “community carving” in Manitoba (or so we believe). Guests will be invited to choose a spot, select their tools, and carve the gargoyle, icon, angel or creation of their choice – no limits. Of course, space is limited, as is time. Accordingly, future guests will be invited to add their own touches to existing carved artworks, or create their own in new space on the poles. Required is individual accountability: each carver will be asked to carve his/her initials in that masterpiece. In this manner, we will have a record of our guests’ visits, an insight into their creative sides, and the most original artwork available.
Cave and rock paintings, innukshuk statues and totems were all communications tools as well as expressions of individualism in our early Canadian culture. It is our intent to continue that tradition, in our little corner (or circle) of the country, and give vent to our friends’ creativity. Want to contribute your own ideas? How about sending us a drawing, photo or sketch of the icon that you would like to see gracing the totems in our yurt. We will be posting photos of the progress on these unique structures, beginning early next year. Let us, and our friends, bring your artistry to life!

Yurt Structural Supports

Although yurts are considerably lighter than conventional houses, there still is considerable weight to the materials, and the proper support structures need to be in place.
Many yurts are built as elevated structures, either in total or in part, since many are built in locations with considerable slopes. There is a tendency to construct these units on simple 4*4 stilts, with little regard to lateral rigidity. Additionally, when yurts are built on platforms or raised decks, they alter the wind flow in, around and under the building. This practice also exacerbates drainage and snow build-up issues, as moisture tends to flow more freely under the building.
The primary consideration should be to structural integrity. Merely walking on a platform or deck that is held up by 4*4 posts causes the building to vibrate. Like the harmonic effect of a bridge structure swaying in the wind (or a child’s swing being propelled on larger and larger arcs), this rhythmic motion can increase in intensity, causing the supports to break loose over time. Cross supports should be used, in addition to ties to hold the structure caps tightly to joists or beams. Ensure that you have placed a sufficient number of stilts along the length and breadth of the platform, to prevent sag.
Wind flow can be a very serious concern for yurt design. A moderate wind, funnelled beneath the yurt, may billow, like the air beneath a parachute canopy. This air flow has a detrimental effect on heating & cooling, as well. Yurts are designed to allow for easy air flow around and over the structure, and were never designed to allow for air flow beneath.
The third concern is moisture redirection. Allowing snow load to build up under your yurt will result in high moisture content in the spring, and the contingent possible decay or mould formation on the underside of the structure. Allowing water and snow melt to drain freely under the platform, as well, will contribute to the undermining of the earthen base on which deck posts rest. This, in turn, decreases structural integrity. You should install a water redirection system on the upper edge of the yurt platform, and redirecting barriers in a lead position on each deck support leg. This will minimize the risk of water erosion.
Just because yurts are considered as an “alternative” to conventional housing does not imply that improper or inadequate construction techniques should be employed. Care in design, construction and maintenance of your yurt supporting network is a critical to building integrity as it is in conventional housing.

Yurt Exterior Skins

Our yurt is designed with two exterior tarpaulin skins. The inner layer is a commercially available tarpaulin skin, intended to provide a secondary protection against rainfall, and a buffer to reduce the amount of friction of edges of the structure against the heavy-duty uv-protected tarpaulin.
The tarpaulins were purchased from Cover-Tech (New Brunswick, Canada), who provided the lowest price quote for a 12 ounce tarpaulin.
The two pieces were custom made, with the wall tarpaulin being 94 feet long and 7’6” high. The extra length will be used to lap over the doorway when we are away for long periods of time. The height exceed the height of the wall structure by six inches, to allow for overlap at the top of the wall framing (under the roof tarp) and excess length at the bottom to allow for water runoff and reduce inflow of cold air in winter. The roof tarp, too, was ordered at 30 feet in diameter, while the yurt was built to 28 feet. The extra foot around the perimeter provides enough material for us to create a partial awning over the windows, to deflect rain and snow.
A small problem occurred with the roof tarp that was easily remedied. The roofline angle (slope) was calculated at 30 degrees. However, after seaming, the tarpaulin was sewn at a 33 degree angle, and our rafter cuts were out by 2 degrees. As well, while the tarp is manufactured as a circle (cone), the yurt actually consists of 44 straight-edge sections. This resulted in a loose fit of the tarp. Normally, this would be a severe problem, as the flutter of the tarp in moderate winds would exacerbate the degrading of the tarpaulin. However, our roof vent design allowed us to snug the tarp over the vent frame, and use only one tuck of material around the entire cone area.
Once the roof tarp was hoisted into place using pulleys and ropes, the wall tarp was erected, and the top edge snugged under the lower edge of the roof tarp. Using a series of ratchet tie-downs attached together, we tightened the straps around both the upper and lower perimeter of the wall tarps, holding the roof top securely against the wall tarp. To ensure that the roof tarp did not free itself from the tie-downs, polyester rope was threaded through the tarp eyelets, and the ratchet tie-downs fed through the rope loops.
Lastly, we cut three-sided openings in the wall tarp for the windows and doorway (the fourth upper side was left uncut), retaining the material to use as a roll-down sunshade.

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.