Graduation Day!

As graduation day approached, we natural builders erupted in a flurry of activity; cleaning up the barn, straightening up the site, adding finishing touches, and reflecting on our collective 11 week experience.  What we shared, what we learned, and how we grew is hard to put into words (which is why it has taken me so long to create this post).  I know that I came away from this experience with a greater appreciation for the natural systems that we are a small part of, a greater respect for the building process, and nothing but admiration for my instructors, new friends, and fellow classmates.

What a joy it was it have our barn filled with live music (thanks to the Yestermorrow String Band), bubbling conversation, tasty food, smiling faces, and positive energy.  Thank you to eeryone who came and participated in our graduation ceremony, making it a truly special occasion.  

And, thanks especially to Deva, Jammin, BG, Julia, Nico, and Natan for making it such a memorable summer.  Bless Up!

Super Insulation

During our natural walls class we insulated our barn' s walls with a couple different insulation systems.....straw bale, wood chip clay infill, and a light straw clay infill.  But to really create a tight envelope, we also need to insulate our 'feet' and our 'head'.  That is, our floor assembly and ceiling assembly are also in need of an insulative material to make this an energy efficient space for keeping warm in the winter and cool in the summer.  

Blown-in cellulose insulation was our insulation of choice for the floor and ceiling cavities. Cellulose insulation is essentially a recycled newspaper material, treated to prevent mold and protected with a fire-retardant.  At 80% recycled material content, a cradle-to-cradle product, and a high thermal performance, it is considered one of the 'greenest' insulation materials.  For more information regarding the advantages of cellulose insulation over fiberglass batt, go to the following website:  www.cellulose.org/green.html

Plaster Master

Time to get plastered!  

Making our own earthen plasters (a blend of clay, sand, chopped straw, and a little bit of water), we covered our straw bale walls at the barn with a 'scratch' or first coat of plaster.  Our walls needed to breathe and dry a bit before we can finish them with a finish plaster coat. So, we took some time away from the barn  and helped around the YM campus, plastering a cob garden shed with a lime plaster, 

plastered the bridge area above the shop with a high-end plaster, American Clay, 

and learned how to make our own natural paints.  During our last intensive week, myself, Deva, Nico and Natan were anxious to put some finishing touches on our barn, so we mixed up a lime finish plaster,

and gave our barn a most beautiful wall finish.

Natural Walls - The Remix Edition

Time for a barn-raising!  The last two insulated wall systems for our barn are straw-bale walls.  The bales are stacked in a running bond, secured to our frame with strapping and stakes, and whatever holes and cracks are created between bales are stuffed with light straw clay knot to make these walls as tight as possible.

You can see the black strapping securing the corner bales to the timber frame and exterior framework.  Corners are notorious for blow-out, so this detail is especially important.

Peek-a-boo!  I am working on the inside of the barn stuffing cracks in the wall with a cob mixture (sand, clay, straw, little bit of water) to prevent any thermal breaks.

Look at this beautifully plastered wall!  After stacking the bales and stuffing all the cracks tightly, our bales were well prepped to receive their clay plaster coating.  We first sprayed down the entire bale wall with a super fine clay slip to give our plaster coat a little something extra to stick too.  The plaster is made up of clay, water, sand, and straw, and applied by hand to the entire wall in a slap and smear technique.  

In summary, natural wall systems are fairly similar to mexican food.  Same ingredients, change the proportions, and the name of the dish/wall is different.  You can see that the light straw clay wall, he cob mixture, the straw bale wall, and even the plaster are all derived from the same ingredients....que bueno!

Natural Walls - Take Two

In contrast to the labor intensive light straw clay assembly along our north wall, our south wall is made up of a wood chip and clay mixture.  After the wood chips, wood shavings, and sawdust are mixed together with a clay slip in a mortar mixer, 

they are poured into a double stud wall cavity faced with wood lath.  No tamping required!  The wood lath will later be finished with a lime/clay plaster.  While this wall took far less time to assemble, it also required more wood as a resource - not only in the insulation mix, but also for the lath.  

However, it does provide us with another example of a highly insulative natural wall system made up of what would be considered by-products form the conventional construction industry.

Natural Walls - The First Edition

Natural insulation is the name of the game for each of our wall assemblies.  The first wall we tackled is a double stud cavity wall along the north end of our barn.  Taking loose straw from our locally harvested and baled straw bales,

and clay slip (a diluted natural clay and water mixture), we mixed it all together like a vinaigrette over a salad to create a light straw clay.  Once all mixed up, we used flat wood panels as form work and stuffed our wall cavities with the light straw clay mix.  Tamping down all of the mix into the cavities proved to be very labor intensive, but a good way to work out any other of life's stresses! 

 And, it was so satisfying to remove the forms and move them up the wall (slip form), and see the section of the light straw clay stay in place.

This wall has a significant amount of moisture in it (due to the clay slip mixture), so we will be letting it dry out for a couple of weeks before applying plaster to it's surfaces.

Gimme Shelter

In preparation for our natural walls class (and after being rained on almost every day), it is time to raise the roof on this barn.  First, we laid 1x18 material (from one of the trees we milled!) above the exposed rafter tails.  This underside of the roof will be visible to the exterior, so we wanted it to  look nice.  Next, we laid 1x4 strapping along the rafters all the way up to the ridge.
Once our strapping was in place, we started hauling our corrugated metal roof panels up the slope of the structure and securing the panels to the strapping with coordinated green roofing screws (with neoprene gaskets).  
In two days we were able to install a roof that is green, albeit not a green roof.