Thursday, May 22, 2014

A brief History of two Strawbale Structures

  This whole process started back in 2008 when Builders Without Borders , under the guidance of Catherine Wanek,  built a small strawbale demonstration building on the terrace of the U.S. Botanic Gardens on the Mall in Washington D.C. The theme that year was Sustainability. I believe the staff at the Botanic Gardens was sad to see the little building go away. With the help of Rob Roy Mackey we hauled the building out to Sam and Kappy's land east of D.C. and plopped it down next to a work in progress, also strawbale. The Studio was built on site using mostly boards cut from trees on site or nearby. Some boards also came from the Glen Echo Bumper Car Pavilion thanks to Ranger Stan Fowler. Stan also gave us all the oak tongue and groove floor boards. The support beams are from the defunct Matapeake Ferry Terminal which was superseded by the Bay Bridge in 1952. Clay for the interior and exterior plasters came from an excavation site in Old Bowie that Sam happened to pass one day returning from work.
  The two buildings represent two main ways of using strawbales. In the Ecohouse the bales themselves carry the load of the roof, hence the name "Load Bearing Style" also known as Nebraska style. The studio was built using a post and beam framework which allowed us to put the roof on first so there was no risk of getting the bales wet during construction. The Ecohouse got some serious rain during its construction, something like nine inches of rain fell during that two week period.
  The buildings have different types of coverings, on the inside we used natural clay plasters with chopped fiber or coarse sand. On the outside , part of the Studio has natural plaster and the side exposed to the harsh weather has a lime plaster. The Ecohouse has all lime plaster which has been painted with mineral pigment colored lime wash. For insulation we used blow-in cellulose. The Ecohouse also has blue jean type batts.
  There are two sections of the roof planted with sedums: the entry and over the bathroom. These consist of a waterproof layer (pond liner) over the roof deck with 4 or 5 inches of growing medium. They have done very well over the years and are almost totally filled in now. If you dig around the older posts you'll see how we did it and where we got the materials. In fact, you can go clear back to day one if you want to, it's all there.

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