This is the second article on building a solid wall
yurt.
Although yurts both are vastly lighter in weight than
conventional housing and offer minimal wind resistance, they, like any house,
still require solid piles on which to rest.
There are a number of options available to provide a solid
base for your yurt, with the simplest and most solid being beams on pad, with
no posts and no piles.
When you opt to construct a solid wall yurt, rather than
tarpaulin and lattice, you add significant weight to the structure, but,
through the use of innovative top and bottom plates, cable reinforcement,
hurricane ties and mending plates on the walls, you can build a yurt that
equals any house for structural integrity.
To design a base system for a yurt by boring piles is an
illustration of overkill, however. Not
only do you change the definition of your building for zoning and permitting
purposes, you provide a degree of reinforcement that is quite unnecessary.
The most cost effective and structurally sound combination
of bases for your yurt is a simple pad system.
However, you may, depending upon the grade and type of soil, need to use
posts and pads, notched pads, crossties and webbing, saddle brackets and so on.
Let us look at the most simple design: beam on pad. Whereas conventional wood frame homes may
require 2 by 12, 2 by 10 or doubled versions of each for beams, imbedded
joists, grade beams, piles, etc., yurts, even as large as forty-two feet in
diameter, will require no more than single 2 by 10 or 2 by 8 beams under 2 by 8
or 2 by 6 joists. For flat terrain with packed soil and good drainage (or in
high wind regions), use a basic patio pad.
For sloped ground, gravelly or soft soil or windy regions, use notched
pads, or notched pads on patio pads secured with anchor bolts.
Begin by ensuring that all pads are level with each other. Simply
lay the beam into or onto the pad, and then tie the joists into position,
sixteen inch on centre separation. Beams
should be spaced a minimum of eight feet apart, with pads spaced four feet
apart for greatest stability. Reinforce
the beams by nailing cross supports between beams at eight foot
separation. As in conventional housing,
joists should be tied together with webbing (2 by 2s).
To use post and pad on heights not exceeding twenty-four
inches, use four by four double saddle brackets and double the beam using a
second eighteen inch length of beam material in the upper saddle bracket. Set the foot of your four by four pile into a
slotted deck pad, ensuring that the top of each four by four posts is level
versus each other post top.
To use post and pad systems on heights exceeding two feet,
be sure to use diagonal cross supports extending from the bottom of each post
to a nearby beam or joist on two adjacent sides, alternating sides with each
sequential post location.
After laying the joists into place on the beams, be sure to
install appropriate headers, using a minimum of four 3.5 inch nails per
joist-to-header connection, and three nails, toe-nailed into place on each beam
intersection.
Since you already have ensured that the structure is level
(by levelling either the pads or the tops of the posts), you should only need
to check level of the joists to ensure that nothing has shifted during
construction. Now, lay your underlay
into place, using 2.5 inch nails. The
tongue-and-grove ¾ inch OSB or plywood should be placed so that edges meet at
the centre of the joist. Use plywood
ties between joists for added structural strength. Your next layer of flooring will be installed
at right angles to the underlay, at a later time.
