West rendering of Casa Sanitas by Rob Pyatt of  Pyatt Studio  ​in Boulder, Colorado. Thick rammed earth walls are to insulate the north side of the house from heat loss and shaded glass is to capture the low winter sun to the south while a thin strip of clerestory glass runs along the north side. Cedar flitch plate beams support the box corrugated steel butterfly roof.
 Southwest rendering of Casa Sanitas by Rob Pyatt of  Pyatt Studio  ​in Boulder, Colorado. Glass doors are to open the space to the exterior and to the views of the Sanitas ridgeline.
 After much consultation and research,  Pyatt Studio  began testing compaction and visual appearance of rammed earth samples in July 2010 by varying the amount of iron oxide, and types of Portland Cement.
 ​The proper amount of moisture, Portland Cement, and iron oxide pigment were my responsibility during the mixing of the rammed earth. All soils used were local and mixed onsite. The correct amount of moisture is imperative for solid compaction.
 Formwork like that used in cast-in-place concrete is built up, reinforced with steel ties and exterior bracing, and filled with the soil mixture. This process is done in small "lifts" of under a foot deep at a time to ensure maximum compaction. All compaction utilized pneumatic tampers. 
 In October 2010, we completed all rammed earth tamping and began to take off the forms to reveal the undulating layers of reddish brown earth mass with flecks of mica that picked up the sun in the mornings. ​The exposed steel ties were later twisted off at the exposed ends.
 The entry to Casa Sanitas (massive glass pivot door to be installed years later as well as the exterior cedar decking that runs at floor level). All rammed earth was built on a 24" concrete stem wall. The play of shadows is quite dramatic along the rammed earth walls--washing out the reds in direct sunlight while deepening and enriching them in shadow.
 Deep steel windows and plumbing and electrical wiring were built into the formwork and rammed earth so that fixtures come right out of the wall.
 On the exterior of the low concrete stem wall, block outs were installed in the formwork and wiring pre-run before the pour to create inset lighting that washes the cedar decking right below it with light as you walk along the entry deck. ​See  this  photo for the completion of the cedar deck below in January 2012.
 All steel pieces for windows and fascia were hand fabricated and welded onsite.
 After the rammed earth, corrugated steel roof, steel fascia, and concrete floor polishing was finished, the cedar deck on the south side of the house begun in November 2011. In winter, the low rays of the sun find their ways underneath the southern deck roof to warm the walls of the house. In the summer, the overhead sun is reflected off the white membrane TPO roof to keep the deck space underneath cool and shaded. ​
 In March 2012 the cedar deck outside of the master and little boys' bedrooms was completed. Many forms of cedar is used on the south side--rough sawn cedar flitch plate posts hold up the deck roof while the exterior walls are to the rough sawn ship lapped cedar planks and the decking is smooth knotty 2x4 cedar lumber. Although fairly soft, cedar is naturally resistant to decay and ​termites and it's warm tones and pleasant smell make it a great building material.
decknorth.jpg
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