The ancient method of cordwood building produces beautiful, rustic-looking homes. The simplicity and charm of a row of stacked logs makes great use of a waste material to build your home.
The History of Cordwood
Cordwood structures can be found around the world, with the oldest standing ones in Greece dating back nearly a thousand years. In heavily wooded areas, using the scrap wood just made a lot of sense. Like most natural building methods, the tradition of cordwood had a rebirth with the green building movement.
What Cordwood Is
Cordwood construction stacks up short, round lengths of wood into a wall. Using what would normally be cast aside for firewood, cordwood looks like a stack of wood you’d have behind your fireplace.
The ends of the logs are left exposed, making efficient use of these leftover scraps of thick branches. The cordwood is held together with mortar, creating a wall with both high insulation and high thermal mass.
As with straw-bale walls, cordwood is not typically allowed to be structural and support the wall. Instead, the stacks of wood are used to fill in the wall between the pieces of a structural frame, even though the cordwood is incredibly strong on its own.
A variety of cordwood, from 1 to 6 inches across, is stacked up in a random pattern (see image below). The wood protrudes from the wall about an inch or so, giving the wall a textured look. The finished walls are anywhere from 12 to 24 inches thick.
You can find your own cordwood from a variety of sources, including fallen trees, timber mills, sawmills, and split firewood.
Tip: No matter where you find the cordwood, you’ll need to remove the bark to prevent water from sneaking into the home. Nearly any type of wood can be used, but the best choice would be the naturally rot-resistant woods, such as cypress, cedar, or juniper. Choose a light wood to keep the logs from swelling and shrinking.
Ideally, you should use the same species of wood on each wall. This ensures that the wood will react to water and temperature the same way.
The process of building a cordwood wall is a lot like laying rows of brick. The logs are set with their ends sticking out, and mortar is placed between each piece. It’s similar to the Lincoln Logs you played with as a kid.
You may be surprised to know that the logs are not treated or coated with anything. The ends are left to breathe naturally. If you like, you can use lime plaster, linseed oil, or sand to finish the exterior of the wall.
Cement-based mortar is typically used to hold the logs together, mixed with sand and sawdust to help it bond to the bare logs. Many green builders have been using cob (see the preceding section) as a mortar instead. The natural clay and straw of cob mortar is a more sustainable alternative, but you need to take the same waterproofing measures discussed in cob construction.
Remember: Practical needs, such as electrical wiring and plumbing, must be planned ahead of time and built into the wall. ....read more