Can Cordwood Houses Be Built on Slopes?

Designing for Slopes

When building a cordwood house on a slope, it’s essential to design the foundation and walls to withstand the forces of gravity and soil settlement. A French drain system can be installed to direct water away from the structure, reducing the risk of erosion and water damage. The cordwood walls should be built with a slight lean to resist soil pressure, typically 2-4 inches per 10 feet of wall height.

Building Techniques for Sloping Sites

To build a cordwood house on a slope, start by excavating the site and creating a level foundation for the house. This may involve creating a retaining wall or a stepped foundation to match the slope of the land. Use a cordwood masonry technique called “log end walls,” where the logs are notched at the ends and stacked to form the wall. This technique allows for good drainage and reduces the risk of water damage. A 3:1 mix of sand to mortar is recommended for the cordwood joints, providing a strong and durable bond between the logs.

Insulation and Weatherproofing

Insulation is crucial for a cordwood house on a slope, as the walls will be exposed to wind and weather. Use a combination of recycled denim insulation and a waterproof membrane to keep the interior warm and dry. Apply a 1-inch layer of insulation to the exterior of the walls, followed by a 1/4-inch layer of mortar to seal the gaps. Use a breathable exterior finish, such as a lime-based plaster, to protect the cordwood from the elements and allow moisture to escape.