Cordwood construction (also known as “bois corde,” stackwall, or log-end building) is a technique in which short, debarked logs are laid widthwise in a wall and bonded together with mortar. The result is a thick, thermally efficient wall with a distinctive round-end pattern on both interior and exterior faces.
How It Works
A cordwood wall is built by:
- Cutting logs to a uniform length, typically 30 to 60 centimetres, matching the desired wall thickness
- Drying the wood thoroughly to prevent shrinkage and cracking after construction
- Laying logs crosswise in a bed of mortar, with the end grain facing outward on both sides
- Applying mortar in two beads along the outer edges of each course, leaving an insulated cavity in the centre
- Filling the cavity with loose insulation such as sawdust mixed with lime, cellulose, or lightweight aggregate
Materials
- Wood species — cedar, pine, spruce, or other softwoods that resist rot; hardwoods can be used but are heavier
- Mortar — lime-based mortar is traditional and allows the wall to breathe; Portland cement mixes are also used
- Insulation fill — sawdust-lime, vermiculite, or rigid foam placed between the inner and outer mortar beads
Advantages
- Excellent thermal mass and insulation when built to proper thickness
- Low cost, especially where cordwood is locally available
- Environmentally friendly, using natural and often reclaimed materials
- Visually striking, with each wall being unique
Application
Cordwood construction is used for:
- Owner-built homes and cabins in rural settings
- Garden walls, saunas, and outbuildings
- Eco-building and off-grid projects
- Workshops and studios where character and low cost are priorities
Walls must be protected from prolonged moisture exposure with adequate roof overhangs and a raised foundation. Proper log drying — ideally below 15 percent moisture content — is critical to prevent shrinkage gaps.
Related Terms
- Log cabin construction
- Cob building
- Straw bale construction
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