Sunday, November 22, 2009

Many Thanks To...


This blog is called “Our House of Straw.” So far, however, we’ve said nothing much about straw. That’s because this first season has been one of preparation. We needed a few basics before we could begin the straw features of our house: road, water, electricity, temporary housing, an enclosed work space.

Our goal is to do as much work as possible using our own puny skills, but, in some instances, it has been necessary to rely upon the expertise of our many skilled neighbors. All of the cement work and the framing of the garage are prime examples. As Wayne, our architect, explained, building a garage of straw is a rather pointless use of time and materials. The footprint alone for a straw bale garage presented a good argument for traditional construction.  It wouldn’t be a heated structure, and we would only ever use it as work and storage space. That’s why Double T Construction was employed.

Still, we want the exterior of the garage to closely match the earthen plaster exterior of our house. Wayne built three structures on his property in Driggs, Idaho: his straw bale home, plus a garage and a workshop that are built with traditional stick framing. To finish the exterior of the garage and workshop, Wayne used a technique that was very common prior to the introduction of drywall - lath and plaster.

This process begins with lath, narrow strips of wood nailed horizontally across wall studs.  The lath is about two inches wide by four feet long by 1/4 inch thick. Each horizontal course of lath is spaced about 1/4 inch away from its neighboring courses. Once the walls are covered with lath, plaster is applied. The plaster is pushed through the 1/4 inch gaps between each lath which “keys” the plaster to the lath.

We thought it would be a simple undertaking to locate lath, but it turned into a quest. After calling many possible sources, we finally found enough lath for the project at the Home Depot in Richfield, seventy miles from Torrey. As the clerks loaded the bundles of lath onto our flatbed trailer, they asked what we planned to do with it all. After they heard the explanation, one fellow laughed and said, “They invented drywall to get away from this.” I don’t think he shared our vision.

One of the last projects of this first season was covering the exterior of our garage with lath. Now it sits, under a temporary wrap of Tyvek, waiting its future handsome coat of plaster.

How Firm a Foundation

When people find out we’re building a house of straw, their first reactions include incredulity and a few jokes about the big bad wolf. Once they realize we are serious, that disbelief turns to interest, and soon they’re asking questions. "What do you cover the straw with?" "How do you keep the straw dry?" If they know a little about construction and then a just bit about straw, they say, "That's going to be a huge foundation!" Yes, indeed, it will be, and we tackled that foundation this summer.

Since the bales we plan to use will be eighteen inches wide, that means we’ll need a foundation that is also eighteen inches wide.  The frost line in Torrey is 30 inches below the earth’s surface. That means we need a foundation measuring 18” wide and 36” - 40” high all around the approximately 150-foot perimeter of the house that will be constructed with bales of straw. That’s A LOT of concrete. To reduce that amount, we opted to build a rubble trench foundation.

To begin preparing the house site, Scott mowed the meadow grass. (We aren’t big fans of mowing or lawn. This might be one of the only times I’ll ever see Scott use a lawn mower.) Then Tyler Torgersen brought in his crew to remove the top soil. Next the crew dug a narrow trench at the house’s perimeter. They positioned perforated pipe throughout the trench. The pipe’s purpose is to drain any moisture away from the foundation. Typically the pipe runs to daylight. Our property doesn’t have much slope, so, rather than going to daylight, our perforated pipe goes to a dry well that is eight feet by eight feet down to about five feet below the surface where the ground water runs. They filled the trench and dry well with gravel. Finally the crew poured about two feet of foundation concrete.
This is where we left our house for the season. It felt grand sitting in the “living room,” looking at the Cock’s Comb to the south and toasting our good fortune.