Clay Building techniques
What is Natural Building?
Natural Building includes a variety of building techniques that focus on creating sustainable buildings which minimize their negative ecological impact. Natural Buildings often rely on non-industrial, minimally processed, locally available, and renewable materials and can also utilize recycled or salvaged materials.
Natural Building ideally incorporates sustainable design practices to integrate the building into its environment. It may also integrate electricity production, water catchment, passive heating and cooling, and alternative waste-treatment.
Why we do Natural Building
Building homes and other structures that are healthy for humans and for the planet is an essential part of sustainability. At Dancing Rabbit we strive towards these ideals as we try to build homes that are functional, aesthetically pleasing, and long-lived. Our idea is to construct shelter that integrates into, and minimizes its ecological impacts on, our land. Shelter that requires the least input, and whose outflows are absorbed by active management of the surrounding landscape.
Of course our homes are not all perfect manifestations of this natural building ideal. Many of our buildings still use some industrial components such as concrete, drywall, steel roofing, foam insulation, and vapor barriers in construction. We are still learning to integrate our homes into the surrounding environment, and in design we think long on trade-offs between footprint and functionality, cost and comfort. Some of our builders are re-forging a construction aesthetic that eschews use of these less sustainable materials.
Natural Building Materials, Techniques & Technologies
There are as many Natural Building technologies in the world as there are climates and bioregions—appropriate materials and technique are largely dictated by the climate and available natural resources of the place the building will stand. Most rely on a handfull of elemental materials: earth (clay), wood, stone, sand, and straw (where straw can be loosely defined to include any dried non-woody plant material such as palm fronds, reeds, etc.). Based on the climate the building must coexist with, these materials can be combined in any number of ways to produce a natural structure.
At DR we have ready access to many natural building materials. We are lucky to have an abundance of clay (though the gardeners may differ on this point), which is a basic ingredient for many natural building techniques. Straw bales are seasonally available from our farming neighbors, but construction-quality wood is in shorter supply in our prairie-savannah ecosystem. Our woodlands are mostly oak and hickory, and we have used some native lumber, but our primary source of building wood is salvage. Before building something new we must often engage in deconstructing something old and no longer wanted. Given the Midwest’s still-declining rural population, such structures are often available.
At Dancing Rabbit we have employed the following natural and alternative building technologies:
Timber Framing – Timber framing is an old natural building technology which uses heavy timbers and joins them using mortise and tenon joints pegged with wood dowels, rather than smaller dimensional lumber and nails or screws. The open bays of a timber frame wall can then be filled in with straw bale, light-clay straw, cob, or any number of other materials.
Post and Beam Framing – similar to timber framing in using larger timbers to carry roof and wall weight over wider spaces, but relies on steel hardware joinery, more accessible to the amateur builder.
Strawbale – Straw bales can be stacked like bricks to make the walls of a house. We have built both load-bearing (roof supported by the bales) and non-load-bearing straw homes.
Cob – Cob is a mixture of sand, clay, and straw similar to adobe, but lumps of cob are applied wet to build up a wall, bench, or as thermal mass around stoves. Like sculpting a home.
Light-Clay Straw – Also called slip straw, clay is mixed with water to the consistency of paint, and then is mixed with loose straw until every straw fiber is coated. The Straw-clay is then packed into forms or wall cavities for insulation. Once dry, dense clay-straw can be directly plastered with earth or lime plasters.