Notes from Windward: #68


Compressed Earth Brick Update

passing the quarter mark

  July 27:

     The compressed earth brick work (CEBs for short) has settled into a comfortable routine that's turning out fifteen bricks every other day. While others could do the work more quickly with more focus and turn out up to a hundred bricks a day, that's not how we tackle projects such as this. Instead, the guide we use is that this sort of work has to feel like a stroll through the park with friends, not like a marathon race to the finish. That's key because within the world of sustainability, there is no finish as one season blends into another, as the output of one system becomes the input for another.

bricks ready for Octangle

     Orly and crew have stuck with the work and I'm delighted to report that they've past the quarter way mark having produced enough 12"x4"x6" bricks to do a quarter of the bricks needed to clad Octangle's exterior. It's slow, physical work, but that's balanced by the knowledge that these bricks will give a life time of service.

     The wonderful thing about passive construction is that once a system is in place, much of the need to spend energy for heating and cooling goes away. Our dining hall's earth sheltered construction allows us to heat it with two cords of wood a winter, meaning that we don't have to cut, haul, split and stack as much wood as would be needed to heat a conventionally constructed building. That's easier on us, our equipment and our forest.

     Not only is an earth sheltered building physically comfortable, there's also a psychological comfort that comes from being in such a building. That may sound a bit mystical, but it's none-the-less real as you'll experience when you enter our earthsheltered kitchen and feel its gentle warmth on a cold winter day, or duck in to escape the heat of a August afternoon. In part that effect comes from the building's thermal stability, but there's also an acoustic effect in earth sheltered buildings. The CEBs allow us to extend that thermal/acoustic insulation to the front of a building as well.

  September 13:

Kerst writes:

     New arrivals Oana and Katie have joined me on the brick crew, relieving Sarah, our resident poet. As we're nearing the end of brick season and trying to beat the rains, we've switched gears. The first building to incorporate the CEBs will be "Octangle" and as the name suggests, it has 8 sides. Therefore, walls will meet at a 45° angle rather than a standard 90° corner. That will require the bricks at the end of each row to have an angle of 22.5° A pattern cut from a piece of plywood is used as a guide for the correct brick angle and as we remove the brick from the ram, I slice it with a length of piano wire.
angled bricks for corners

     As you can see in the photo, some of the new bricks are nearly full length while others are only half sized. When laying bricks, it's important to avoid aligning joints vertically, so inserting half bricks will allow us to stagger the rows--preventing drastic temperature change and increasing the overall integrity of the walls. Our typical yield is about 5 standard bricks per mix, but with the angled bricks we're able to get a 6th brick out per batch. The first 4 are "full length" angled bricks, which we make by taking a regular brick and cutting off the end at 22 1/2 °. We re-use the cut-off ends to create the 5th and 6th bricks which are then cut as half-length angled bricks. All together we're getting 4 full length and 4 half length angled bricks per batch with very little material going to waste.

Notes From Windward - Index - Vol. 68