Visit some good friends of Blue Rock Station...

Building a Straw Bale Privy

One of the disappointments with any project (especially one that uses labor-intensive sustainable techniques),  is that they seem to take so long that you rarely see substantial progress over a day or even a week’s time.

This little project, our “Straw Bale Privy” is an exception.  It is small enough that you don’t get bogged down in any one task for long.

The process follows the same steps as any larger straw bale project.

The construction process...

• The Tire Foundation
• Waterproofing (keeping its feet dry)
• Framing the Structure
• Building the Vaulted Straw Bale Walls
• The Can/Bottle Walls
• Earth Plasters
• The Roof
• The Finish Work

The foundation for this project is constructed using Earthship building techniques - out of discarded tires and earth..  A booklet outlining the process for building a tire foundation is available on this site.

We then used some salvaged barn beams to frame the structure.  As this building was going to have a “living roof”, we knew we needed some fairly hefty support.

We filled in the side cavities and the bottom of the back with straw bales, lashing and sewing them together as we describe in other sections of this site.

The roof decking was going to support a lot of weight.  The living roof is comprised of a layer of gravel (for drainage), landscape fabric, soil, and plants.  That weighs plenty in itself.  But it will also retain a tremendous amount of water - so we overbuilt the roof.

Studs were placed on one-foot centers, and the decking was ¾ inch plywood.  

When constructing the foundation, we built it two layers high (about two feet).  This left a fairly deep but small hole in the center.  After waterproofing (with plastic sheeting) we filled the cavity with rocks and sealed plastic bottles.  I had never tired this before - so figured a small project like this was the place to experiment.  

My thinking was that filling the cavity with trapped air (inside the sealed bottles) would provide a bit of insulation in the floor.  Also I knew that the floor would not hold a substantial amount of weight - so structural integrity was likely not an issue.  My big concern was if the floor would crack over time (perhaps some expansion and contraction in the bottles).  We have gone through one winter and no problems at all - so perhaps this little experiment is a success.

As this privy was to be our “public” toilet (for the literally thousands who visit Blue Rock Station each summer), we thought it appropriate to give it the official half-moon design.  This was done by placing beer bottles “top-to-top”, with the bottom exposed on both the outside and the inside.  In theory this will allow the light to pass through the chamber and glow inside and out.  In practice because the bottles are so dark and the wall does not receive direct sunlight, they don’t do a lot of glowing - but it is still a cool design.

We then finished the earth plastering - and gave it all a coat of lime wash.  We decided to tint the wash using dye made from Queen Anne’s Lace flowers (method outlined).  It give the entire structure a beautiful buttery color.

The privy now houses a commercial compost toilet (Sun-Mar Excel) and visitors are treated to a beautiful view of hills of southern Ohio.