In straw bale buildings, baled straw from barley, wheat, rice, flax, rye or oats is used to build the exterior walls of a house or shed. The building can have any of the traditional foundations used in Canada. Around the perimeter of the main floor a "curb" is built. The curb is a railing of two 2x3's nailed to the floor on which the bales are set. Bucks (framing) are built to hold the window and doors. The bucks are temporally held in place with bracing to the floor. Baled straw is stacked on the curb in a brick like fashion around the bucks. Headers (a rail or top plate built of wood framing) are built to sit upon these straw walls.
Using the post and beam straw bale infill method on the second story
There are two common methods of building straw bale homes. The first method is called a post and beam with a straw bale infill. Here a wooden structure is built first and the bales are stacked between the framing and used as insulation. The second common method is called load bearing. Here the entire wall consists only of bales and there is little or no wood or steel framing in the wall. However, the load-bearing wall must be compressed with cables or wires to stabilize it. For either type of construction, the bales are covered with mesh which is stitched on with giant bale needles. On top of the mesh, two or three coats of plaster are applied. There are many different kinds of plaster which may be used, including earthen, lime or lime/cement.