The cob building technique has been around for thousands of years. In Europe, some cob homes have been standing for more than 500 years. Earthen cob homes were green and environmentally friendly before anyone ever even knew what that term meant.
What is cob?
Cob is a building technique similar to adobe. Cob homes are constructed with simple, widely available, natural materials that are usually just under foot. The basic ingredients, sand, clay, and straw, are thoroughly mixed, and formed into loaf-shaped building blocks. They are then laid on the foundation, and sculpted into its final shape.
The unique properties of cob
Once cob dries, it is similar in density to concrete or rock. Cob walls can be anywhere from one foot to three feet thick, capable of storing an incredible amount of heat. Their thermal mass serves as a passive solar conduit, releasing their stored heat to provide warmth in the winter, and natural cooling in the summer. Cob homes are sculpted and molded, so they don’t have to conform to a right-angle world. They can be shaped by the builder however they desire. There is an incredible amount of freedom of design when building with cob. Once the walls are slathered in plaster, which itself is easily formed and styled, it will withstand just about anything Mother Nature can throw at it before showing any significant signs of weathering.
Easy to build
An architectural or engineering degree isn’t required to build a cob home. Cob homes have been around for so long, the building instructions are almost inherent in our genetic makeup. Man has needed shelter for millennia; it’s is a matter of survival, and naturally, earthen shelters made of locally available materials comprised the first sheltered structures. Short, intensive workshops are available, and combined with some basic research, the essential elements flow naturally and easily. It is extremely rewarding to build a home with your own two hands, and an almost amazing innate knowledge takes over.
Healthy and green
Cob homes are not constructed with modern building materials. Chemicals and industrial “ingredients” aren’t utilised. Worries of environmental pollutants from materials that put out toxic fumes are non-existent. And because cob in made from natural materials, it is still able to breathe through its tiny pores, keeping the air cleaner and healthier.
No noise pollution
With their massive earthen walls, the acoustics and sound absorption in a cob home is bar none. The walls absorb sound, keeping the peace both inside the home and protecting it from outside noise.
A cob structure is naturally fire-retardant, although depending on materials, the roofing structure may still be able to catch fire.
The straw component in the cob mix acts as nature’s rebar, holding the entire piece together, binding it as one. This strength is one of the primary reasons why the structures stand the test of time. Earthquakes and tornadoes have a formidable opponent when it comes to the strength and integrity of a cob home.
Unfriendly to critters
With very little or no wood used, termites don’t come around, wreaking havoc on your structure. Rodent infestations, bats, and other bugs have a hard time gaining entry and establishing a foothold as well.
One of the best things about building a cob home is that they can be very inexpensively constructed. It is an uncertain world we live in, and with no end to the latest recession in sight, taking out a thirty year mortgage almost seems a foolhardy thing to do. The primary building materials are frequently yours for the taking on the land on which you plan to build, and what can’t be secured this way isn’t much of a worry, as the materials are easily, inexpensively, and locally purchased.
Other supplies, such as windows and doors, can often be salvaged or foraged for, for free or next to nothing, and are often of a higher caliber of quality than their modern-day counterparts.
Besides the obvious differences between cob and conventional building techniques, cob homes are very unique in the sense that they can be shaped literally to fit your lifestyle. Cob home are built on a smaller scale than the average new construction. Most people don’t need a mansion and the mortgage that goes with it. A cob home can easily have nooks, and crannies, storage areas, and built-in bookshelves or cubby holes sculpted in during the building process. With a bit of a careful examination of how you run your life – where you put your keys, take off your shoes, read, relax, eat, play, and love – your final design can encompass all of these needs, utilising the best of the space you have, and working with you rather than against you.
About the Author
Nisha has been writing about DIY and home renovations for a few years now. She enjoys reading various health articles from http://www.stancliffe.com and other similar sites.