Tuesday, May 26, 2015

Peace Riders Spirit House

In every walk in nature one receives far more than he seeks.  John Muir
Creativity takes courage.  Henri Matisse

 It didn’t start out that way but as the various pieces were built and assembled I began thinking of the design that came to me and the space I was creating as a spirit house.

I was moved to try and create a super insulated round house that retains some of the desirable features of a yurt.  The yurts available for interior Alaska are under insulated for the climate.   One of the features is an open circular inside space. A circle is a symbol of unity.  Window placement will be in the north, south, east and west directions to honor what is called the World Tree, Tree of Life or the four stations of the Christian cross.  An east window may be in the door.  An eight sided pyramid shaped skylight will sit atop the upper compression ring to allow light into the center of the structure.  Outer coverings of roof and wall will be of durable UV resistant material.
Skylight without double walled acrylic panes.
A principal difference of this design is use of a light weight truss with an overhang.  It will shed water away from what is called a remote wall; six inches of foam board in one inch layers, screwed through a 6 mil vapor barrier on the outside of  plywood sheathing.  

The basic framing was completed by the middle of May when I interrupted construction for a trip to visit friends in Panama.   All the supporting scaffolding erected to hold the compression rings in place during installation of the trusses was removed.

My intention in moving ahead with this project was to create an affordable space that required minimal site preparation, was relatively easy to build (emphasis on the relative since some specialized tools were used like a band saw) and is still portable up to the point I halted construction.  Beyond this stage disassembly becomes less practical.  And of course, it is not yak portable or even as portable as more conventional yurt construction but nonetheless could be done with some effort.  And I may just move it to another site but have made no decision in that regard at this point.

Some of the construction details follow for those of you interested in that sort of thing.   It is 24’ in diameter or roughly 452 square feet inside.  The  platform is supported on 13 concrete piers holding 4x8” horizontal cross beams on 5’ centers ( doing it again I would space them on 4’ centers so I would not have to cut 2”x4’x8’ sheets of foam boards I fastened to the bottom of 2x10” floor joists to stop air circulation through batts of fiberglass above).  The walls are 2x4’s on roughly 2’centers prefabbed in eight foot sections, 6 1/2’ to the outside of the top and bottom plates.    Top and bottom plates were cut on a 24 foot arc from 3/4 inch plywood using a circular saw.   The top plate was doubled and overlapped to join each wall section around the perimeter.  Horizontal 1x4” nailers of green spruce were bent and screwed to the stud walls, on roughly 2’ centers.  Three eighths inch plywood sheathing was screwed to the nailers.  Plywood bent around the perimeter of the platform extended 1 1/2” above the base of platform.  The bottom horizontal nailer was screwed to this which in turn held each wall section in place.  Thirty-eight trusses, 26” deep were built on a form.  The top and bottom pieces are 1 1/2”x 2 5/8 ripped from spruce 2x6’s.  Later 2x4’s of selected local dry spruce were used and ripped because they were dimensionally more stable.  The unplanned bonus was a left over strip I can use to hold the interior ceiling fabric in place against the bottom of each truss.  Interior reinforcing webbing was of 2x2’s gusseted on both sides at the joints.  Gussets were 1/4” OSB glued and screwed in place. 

Each truss is bottom notched centered over a supporting stud and held in place by a slightly elevated 5/16” galvanized steel cable around the perimeter similar to yurt construction.  Two 5 1/2’ OD, compression rings were made and routed to hold each end of the truss.  A 1/8 inch layer of birch plywood was bent and screwed to the outside of each ring, then edge sealed with silicone to form a vapor barrier between the two rings.  It will also hold in place fiberglass insulation to be added during a later phase of construction. 


Looking through covered skylight opening.

That’s my story and I’m sticking to it; more to follow from on the “way” in Panama.  

Art is not what you see but what you make others see.  Edgar Degas

Where words fail music speaks.  Hans Christian Andersen

Peace Rider