Can Cordwood Be Used in Combination with Other Natural Building Methods?

Combining Cordwood with Other Natural Building Methods

Cordwood masonry is a versatile construction technique that can be paired with other natural building methods to create a harmonious and eco-friendly building. One approach is to use cordwood for the exterior walls and combine it with rammed earth or straw bale for the interior walls. This allows for a thermal mass effect from the cordwood, while the interior walls provide added insulation and a natural, earthy feel.

Insulation and Thermal Mass

When combining cordwood with other natural building methods, it’s essential to consider the insulation and thermal mass needs of the building. A common technique is to use a 2-3 inch gap between the cordwood logs and the interior walls, filled with a natural insulation material like straw bales or recycled denim. This gap provides a buffer against temperature fluctuations and allows for a more efficient use of thermal mass. To achieve optimal thermal mass, the cordwood logs should be stacked in a way that allows for at least 6-8 inches of solid cordwood on exterior walls, typically 12-18 inches for insulated cordwood.

Mortar Mix and Log End Walls

When building a log end wall using cordwood, it’s crucial to use a mortar mix that is compatible with the natural materials used in the construction. A mix of 1 part cement, 1 part lime, and 4 parts sand (by volume) is a good starting point. This mortar should be applied to the ends of the logs, creating a tight seal that prevents air leaks and moisture intrusion. To ensure a strong and durable bond, the mortar should be applied in a thin layer, no more than 1/4 inch thick, and allowed to set for at least 24 hours before adding additional coats.