Cob, the great moderator

Of all the different natural building techniques and methods, cob seems to be the most magical one. It is among the cheapest of materials and just about anybody can do it anywhere. Mixing some sand, clay and straw together (in the right proportions) will give you a building material that is strong yet soft, warm yet cool. You then proceed to sculpt your own house and are able to come up with shapes and features that are beautiful and limitless in their possibilities.

Almost without exception people feel the beauty and the magic of a cob home as soon as they enter one (or even when they see photographs). On a subconscious level, I believe that cob and cob buildings have a moderating effect on many aspects of our living experience. Moderating in the sense that cob resolves inner conflict in our bodies and our souls; we experience it as something right. The quality of this deeper experience can be compared to walking through a beautiful forest where we find ourselves surrounded by something that feels complete and sensible.

Bringing people together The building of a cob home tends to bring people of all walks of life together and has a moderating effect on groups. People sense their commonality in the joy they find in “playing” with mud and getting dirty. They are allowed to emerge in these deeply rooted activities again. It is as if they have landed on a newly discovered planet with a bunch of very exciting people. Because cob building is relatively easy to learn and creates beautiful products it tends to help us focus on our commonalities; almost without exception, every cob workshop I have been part of has led to a joyful building community where care, cooperation, fun and responsibility were the leading themes. This feeling is enhanced by the near absence of power tools.

Cob moderates our bodies too. All muscles of our body are being used while building, while none need to be strained. It feels like a gentle exercise, aligning our bodies and gaining strength on all levels. Mixing the cob by foot and using your hands to put it on the wall is similar to the best foot and hand reflexology treatment. Through the gentle massage of your hands and feet, you feel your body being energized and stimulated. I know of one story of a person who came to a cob workshop with a chronic illness and left feeling strong and healthy. When I started teaching my last cob workshop, I started with a stiff, painful back; afterwards I cancelled my appointment with the chiropractor because I felt so good.

Upon entering a cob building you notice the acoustics being different. It doesn’t sound hollow and it doesn’t sound dead. When we were ready to move into our cob/strawbale home we noticed that even without any of our stuff being in the building, the sound was not hollow at all. We didn’t expect this, as we have a very high ceiling and a hard, earthen floor. The reason why cob moderates the sound is because of its relative softness and the uneven surface of the earthen plaster (and floor). The sound doesn’t get absorbed too much (as with carpeted rooms) and doesn’t get bounced around too much (as with spaces with lots of glass, concrete and hardwood floors). Our voices sound bright and pleasant along with our musical instruments.

Cob is heavy, therefore it has the ability to absorb huge amounts of heat and moderate the temperature in a certain space. In the summer time our cob absorbs heat during the day, keeping the house cool. With the windows open at night, lower temperatures cool off the cob so it can absorb more heat during the following day. In the wintertime, the sun, as well as our stove, warms up the cob during the day and at night it radiates the stored heat out into the house. The result is that even if it freezes outside, our house is still comfortable in the morning, without keeping the stove going all night. People who have greenhouses can use a similar trick. They have to deal with extreme temperature differences caused by the huge amount of glass and the lack of insulation. They may put a bunch of trashcans (or 55 gallon drums) inside the greenhouse, paint them a dark color, and then fill them up with water. Water has a great ability to store heat (even better than cob or stone), and consequently, the greenhouse won’t be as hot during the day and not as cold at night. It is also for this reason that hotels can get away with enclosing their swimming pool with a glass building.

The shapes of living spaces Cob moderates spaces. Cob structures don’t need to be too big or too small, but just right. Because you actually sculpt your walls, the shapes of the living spaces can be according to your needs and the shapes of your bodies, as opposed to the size of standardized building materials: Rounded walls avoid dead corners, built-in furniture gets rid of useless space behind the couch and low internal walls can help separate spaces just right. Because of its beauty and limitless possibilities, cob is also an ideal medium to repair existing spaces.

The best cob has a clay content of about 20 – 30 %. It therefore has the ability to control and moderate the humidity of a space. Moisture moves in and out of clay so easily that the cob walls soften any extremes of dryness or humidity. We have noticed that in particular in our house during periods of cold, dry weather. Even with the wood burning stove going, we would never get that familiar dry indoor air. No static sparking and no dry noses. To avoid breathing this dry air in the wintertime must greatly enhance overall health. Our kids very seldom have crusty dry noses, even when they do have a cold. I haven’t heard any stories from people who live in cob buildings in areas with extreme summer humidity (Florida). I’d be curious to find out if and how the cob helps make the indoor space more pleasant, without resorting to air conditioning.

Building and living with cob is wonderful. I have yet to mention the moderating effects on your financial situation or cob’s relative positive influence (compared to conventional construction) on the earth’s eco-systems. Clinton was known for saying that we can take care of the environment as well as achieve economic growth. I am not so sure about that. What I have discovered in my life is that we can “take care of the environment” and as a result of this action improve the quality of our lives.