Thursday, October 8, 2009

Preparing For the Bale Walls

The straw bales were set to arrive around the end of September.  Before they could go up, a stem wall was to be constructed to lift the bales up about 18" above the ground to minimize any chance of moisture getting into the walls from splashing rainwater or deep snow cover.  The crews from Natural Design Build, and New Frameworks Natural Building worked to build a concrete block stem wall, with a wood framed chaseway on the inside of the walls.  This would provide an easy way to run wiring, propane gas lines, or other mechanicals along the inside of the walls.

First, blocks were laid out around the frame, atop the concrete/ICF "beam" supported by the rubble filled trench.

Ace McArleton, of New Frameworks Natural Building, mixes mortar for the block wall.

Ben Graham, of Natural Design Build, sets blocks to create a bale supporting stem wall.  Deva Racusin at left, and Nick and Nick prepare the wood framed chaseway.

Each block is checked and trued up before progressing to the next one.  The stem wall will be covered with a parge coat of a fiber cement that will hold all the blocks together.  More about the structure of the stem wall in a few days.

Here I'm checking out the rafters and the shed extension framing on the north side.  The old rafters were 3 x 5 and were sistered up with new 2 x 12's to create a cavity about 16.5" thick.  The north shed extension is framed with "I-beam" rafters of OSB and solid wood.  This will be sheathed with 1/2" plywood and filled with high density cellulose,eventually creating a roof cap of about R-65.

Work continued on the stem wall.  It's composed of two courses of concrete block capped with 3" patio blocks.  The cavities are filled with Vermiculite and Pearlite to offer a little more insulation than the concrete would.  Sheet foam and dense pack cellulose will insulate the wood framed portion of the stem wall, bringing it up to around R-32, about the same as the bale walls.

Everyone's working like crazy, inside and out, to get ready for the bales, which are due to arrive soon.