Natural building as a way of restoring personal, social, and environmental health
One of the simplest and most effective ways to restore balance, harmony and health to our world is to create our shelter utilizing natural materials from our local environment. Not only do we save energy by reducing production, shipping and storage of manufactured materials… but the materials themselves – particularly the combinations of clay, sand, plant-fibre and water, are very health enhancing to work with. Furthermore, because certain aspects of a natural building process are suitable for involvement of all ages, all members of the family and community can work together to create comfortable, healthy, durable low cost shelter.
Throughout the ages people in all regions of the world have created comfortable low-cost homes utilizing materials from their local environment. These pueblo dwellings in the Mesa Verde of Four Corners, South-Western USA were constructed from adobe bricks made of clay, sand, water and plant fibre. The walls were then smeared with a ‘cobb’ plaster of similar material. The floors were filled with the same, and the ceilings consisted of timbers to span the openings with thinner sticks woven between and then packed with cobb. These buildings have stood the tests of time.
This traditional Cherokee Asi dwelling was made by standing logs on end and creating a latticework of twigs and sticks between the logs and then mixing the red clay with plant fibre and water and smearing it into and onto to the framework. This is similar to an old practice in Europe known as ‘wattle and daub’. The Asi wall is built up until it is about a foot thick. The roof is thatched with layers of branches, twigs, grasses and mud. A vent is created in the roof for smoke from the fire to escape. The windows are covered with a latticework of river cane strips. A hut like this could have a variety of uses, ceremonial lodge, meeting space, or perhaps to house the elderly during the cold months.
Building naturally involves a consideration of the most appropriate techniques for any given bio-region. For example, on the Praries, building with straw bales makes sense because of the abundance of local straw, the superb insulative qualities of the bales, and the relatively dry climate with extreme annual temperature fluctuations. In warmer climates to the south, more dense sand-rich mixes of cobb and adobe brick are most suitable. In temperate rainforest regions such as ours, a very appropriate technique is light-clay.
Pictured here is a 500 year-old light-clay barn in Germany.
Light-Clay is a natural building technique that has been practiced in temperate rainforest regions of Europe and Asia for over 1000 years. Birds (and maybe dinosaurs) have been at it for much longer. This process was once a very common practice in rural areas where members of farming communities gathered to help build each other’s dwellings. With an abundance of straw from the field crops, and an inexhaustible supply of clay rich soil not far underfoot, these materials were the natural choice for infilling the areas between the light timber frames structure.
Creating walls with light-clay involves erecting a wooden framework (eg. post and beam and or stud-framing), and then filling the cavities between with a mix of (20%) liquefied clay and (80%) plant fibre. This slightly damp slurry is lightly tamped in place, then the form-boards are moved up the wall another foot or so and the process is repeated. The clay acts as the glue that binds the woodchips together to form a light but solid mass as it dries and hardens. Another way to infill with this material is to gradually place lath on the stud frame and infill the cavity with loosely placed material. The lath remains on the wall and the cobb plaster is applied onto/into it.
Once the infill material has dried, a ‘brown coat’ of natural plaster consisting of clay, sand, and fine straw fiber is applied. Shortly after, a smoother finish clay plaster is applied by brush, sheepskin or trowel.
Specific benefits of light clay wall systems
Low embodied energy. By utilizing naturally occurring materials that are harvested on or close to the building site, we reduce the hidden ecological costs normally associated with industrial manufacturing, transporting, storage, and eventual waste disposal of hi-tech building materials. Here in the valley clay is an immediately available soil commonly found in most building site excavations. Also, nearby gravel mining operation fill their waste settlement ponds with pre-liquified clay that they are happy to scoop into dump trucks and deliver for a nominal fee.
One of the most effective plant fibre infill materials here on the coast is Douglas Fir wood chips – a highly abundant byproduct of local saw mills and woodworking operations. Pictured here are my sons Rhys and Isaiah playing in a freshly delivered 25 yard pile of planer shavings. The load cost $300 (trucking fee) and once mixed with clay will fill 500-800 cubic feet of wall. The smell of the resin is wonderful.
When clay releases moisture into the atmosphere it also releases negatively charged ions. These ions enhance our health by neutralizing free radicals within our bodies. This has a calming effect upon our mind, which helps us attain deeper states of relaxation wherein all manner of natural healings can occur.
For those involved in the building process, having one’s hands in woodchips, clay, sand and water all day is inherently curative. Quartz crystals in the sand help to balance our energy fields and clay draws toxins from our bodies. The clay also draws resins (pitch, smudge medicine) from the wood chips, which helps to soothe and protect us as intensities are drawn out and dispelled through our skin. The materials smell wonderful together, calming the nervous system as they evoke ancient re-minders of well-being.
Optimal indoor air quality. Non-fired clay surfaces absorb and release moisture to maintain indoor air humidity at 50-60%. Many clays are able to wick and absorb 30 times their weight in water without wetting out, and are much better than concrete at re-releasing moisture back into the atmosphere. This prevents moisture condensation within wall cavities, which eliminates conditions that lead to formation of mold. This ongoing balancing and regulating of indoor humidity also creates an environment that is optimal for our lungs, skin, and all the mucous membranes within our bodies.
Clay moisture cycling also evokes a slight electrostatic charge in the atmosphere causing airborne spores and dust particles to clump together and fall to the ground. This further minimizes the potential of danger to our respiratory systems. All in all, light-clay walls naturally evoke a mold-free environment throughout the lifetime of the building.
Clay is very hygroscopic, meaning it can hold and transfer significant quantities of moisture through its mass without dampening fibrous material around it. The moisture transfer occurs at a sub-molecular level via a process of ‘ionic binding’ between the + and – hydrogen electrons in clay and water. Many of the old Light-Clay farmhouses in Europe are still functional after 400 years (some as old as 1000) due to the moisture wicking properties of clay which preserves the wooden framework and wall infill fibre through all kinds of weather.
Pictured here is a sweat Lelem we built near Georgetown (up river from the white bridge over the Cowichan River). People of all ages were involved, including my two young boys who hopped right in there. Shortly after the roof was up and walls plastered the lodge experienced two weeks of flooding and repeated freezing and thawing. At times the water level was 12 inches up the walls. At one point Salmon were swimming inside taking a break on their way home to spawning grounds. The building sat wet all winter, but by next summer had dried itself out completely. The extent of the damage was some erosion of plaster below the high water line. Once the walls were painted with a final clay-lime solution, the building was ready for ongoing use. Essentially, the building self-remedied.
Light-clay infill can be combined with any wooden framework. Shown below is a double stud wall framed in parallel (also known as Larson trusses). These studs were placed to create a curvilinear shape.
Just above the formwork one can see the top tube of a run of in-wall hydronic heating. By placing the heating elements in the walls, the direction of radiant heat waves is optimized to contact a larger surface area of our bodies. Studies from Europe where this practice has become common show that people are able to set the thermostat 3 degrees cooler than with other heating methods while feeling the same level of warmth.
Studs can also be staggered on either side of a common top and bottom plate. Internal diagonal bracing or plywood bracing in the corners can be added to boost sheer strength (determined by the building’s centre of gravity and seismic requirements). Where timber-faming is involved, a simple sub frame with members on up to 36” centres helps to create the ribs to be infilled. The utilization of stud framing enables easy interface with sub-trade applications.
Improved R-value and U-value
Light clay walls are typically built 12” thick. This so as to offer an R-20 insulative value equivalent to that of a 5.5” batt of soft insulation. However, because the wooden framework in a light clay wall is rarely continuous from inner to outer surfaces, heat loss via thermal bridging is radically reduced. Furthermore, light clay walls offer considerable U-value, which is the capacity to absorb and release heat into and from the inner few inches of the wall. This creates a long flywheel storage of heat that is not lost every time a door or window is opened. All in all,light clay wall systems offer 50% better insulation than a conventional 2”x6” framed house.
Light clay building as social enterprise
The most efficient way to build with light-clay is to involve ‘many hands in’ the process. This is a rare situation in which people gathering to work alongside one another can be more cost effective than mechanization. This evokes a profound opportunity for community involvement.
Building shelter with light-clay is an ancient experience. The infilling work involves a range of motions so simple and gentle that most anyone of any age or ability can offer a genuine contribution. The infilling of lower wall sections can be led by the younger ones. The infilling of higher wall sections involves an element of agility that teenagers can excel at. If it is true that ‘our issues are in our tissues’, then this kind of inherently soothing activity, with a lateral emphasis upon an overt task (rather than a therapeutic focus upon ‘what is wrong with me’), can be facilitated to evoke a safe environment for anyone to shed their intensities.
If we opt to establish an element of paid professionalism, we can guarantee an entry-level apprenticeship income for many a ‘dis-advantage’ young person who might otherwise be struggling to find meaningful purpose and expression. Sensing the concrete results of one’s efforts each day feels good. Knowing that one’s efforts are genuinely valued by family, community and the Earth feels even better. When people experience dignity, all manner of troubles resolve. As we welcome ‘troubled youth’ within our community to play a valuable role in manifesting our basic need for health-enhancing shelter, our interactions between generations become more positive. We experience mutual benefit. Intensities are resolved. Our communities are renewed.