How To Build a (Semi) Solid Wall Yurt

The handbook, "How To Build A Yurt (solid wall design) is now available at www.robertflee.com or at www.robertflee.books.php. To purchase this handbook from Amazon or Smashwords, visit www.smashwords.com or www.amazon.com and search for the title under the author's name, Robert F. Lee. The semi-rigid walled yurt described in this booklet can be constructed in less than 40 hours and assembled or disassembled on site in under three hours, by one person!

Thursday, March 20, 2014

Yurt Chimney Vents

While most yurt skins are treated with fire retardant, this does not mean they are fireproof, nor that they will resist sparks that are wind driven or generated by “punk” firewood. Like tents, yurts that are treated still will develop holes as hot embers hit them.  However, they do resist flaming. However, the space age bubble insulation used on the interiors of many flexible wall yurts, as well as they solid EPS or high-density foam insulation employed in rigid all designs can erupt into flames, and some of the petroleum-based applications can produce toxic gases.  For this reason, it is imperative that any heaters, stoves, kerosene lanterns or candles be placed and installed so that the risk of coming in contact with flammable materials is eliminated.
The EasYurt portable yurt is one of those kits that require attention to fire protection techniques, even though it, like other name-brand packages generally are quite safe.
The use of propane heaters or kerosene units is not recommended in any closed space, since they suck oxygen out of the inside air quickly. When using flame units that generate quick and intense heat, always make sure that there is adequate ventilation.
Electric heaters, too, need to be placed so that they are a sufficient distance from walls and flammable surfaces.
One of the common appliances used in yurts and cabins are tankless water heaters.  These units have a short chimney that extends less than a foot from the wall-mounted units.  This, by definition, means that their hot outlet vents are inches from exterior tarpaulin skins.  Similarly, wood stoves, popular in ice fishing shacks, often are vented out of the walls of cabins and yurts, with live sparks floating less than a foot from the walls.
Two key preventive measures can reduce the risk associated with flame, high heat and sparks coming in contact with these flammable surfaces.
First, outlets should always be on the downwind (leeward) side of any surface, so that heat and sparks are dissipated away from the building.  That downwind side is the one farthest from approaching prevailing winds, during prime heating seasons.
In summer, wind direction often swings to a more southerly direction in the northern hemisphere, but prevail from the north and northwest during spring and autumn.  Thus, the stacks, vents and chimneys should be on the southeast side of any building, even though that may be the warm side of the building.
The second preventive method should be to install the required outlets in an existing window frame.  The window unit is replaced by a dual-layer aluminum sleeve that fills the window space, with fibreglass insulation or sand packed between the aluminum layers.  This acts as a heat bridge, so that the chimney or stack may be quite hot, while, at a few inches from the vent, the temperature is considerably lower.
All vents should also have baffles, both to prevent wildlife (birds and rodents) from entering the chimney, and to diffuse heat and arrest sparks.  Lastly, the vent should include a rain cap that further redirects heat and sparks.

While these steps will not eliminate fire risk entirely, the chance of damage or fire is greatly reduced.

Sunday, February 16, 2014

Solid-wall Yurts Easier to Move

The original premise of the Mongolian yurt was that it was to be somewhat portable.  While the Mongols lived in their yurts for a substantial part of the year, when the dead of winter hit in the high Himalayas, these semi-nomadic people moved lower down the mountains, packing their felt, skin and pole –framed homes with them on carts.  They were hardly light enough to transport by hand or skid.  Today, we build abridged and hybridized versions of these very early homes, but we have lost much of the portability of the original ger.
One of the reasons is that we have a great deal of lattice framing to handle.  While the lattice is lightweight, the assembly and disassembly of the frame is time consuming.  Along with that impediment to mobility, the roof ring also requires more than one person to erect and install, and the layering of the outer skins requires a delicate balance of adjustment and readjustment. If the bubble insulation is used, this provides an additional round of stretching and securing into place, most often requiring an extra set of hands.
The semi-solid wall yurt provides much of the benefit of the solid wall yurt, while actually decreasing the weight of conventional flexible walled designs.  At the same time, the insulative value of the rigid insulation that forms the core of each solid panel provides a protection against temperature fluctuations from hot to cool. This design has been found to provide a comfortable environment when the outside temperature varies from plus 35C to minus 25C – a full 60C (108F) variation.  The wall design can support a roof load considerably greater than that of flexible lattice designs, too.
However, one of the primary advantages of this semi-solid wall system is that it can be erected in less than 2 hours and broken down into components in less than one, with only one person required for the tasks.  That makes it ideal for medium-term camping, for setup in summer months and storage in winter (making it an optimal lakeside guest house), and for portability.  Although the unit requires more storage space than a flexible wall yurt, a sixteen-foot diameter yurt can easily be transported in the back of a half-ton truck, or on a small utility trailer, as its weight does not exceed 200 pounds (excluding floor and joist system).

A portable yurt may seem unnecessary for most applications, since they often are set up and remain in place.  However, given that almost no flexible wall yurts meet engineering standards that will allow them to be substituted as permanent, permitted structures in zoned or code-controlled areas, the only way to bypass permanent home rules is to be able to erect and disassemble the units rapidly.  This gives them an exemption as temporary structures, similar to portable garages.  With a 90-day window common for these buildings, the semi-solid wall yurt provides the capacity to build and de-construct the unit rapidly, allowing them to qualify for use in zoned areas.