Definitions

AU102.1 Definitions. The following words and terms shall, for the purposes of this appendix, have the meanings shown herein. Refer to Chapter 2 of the International Residential Code for general definitions.

BRACED WALL PANEL. A cob wall designed and constructed to resist in-plane shear loads through the interaction of the cob material, its
reinforcing and its connections to its bond beam and foundation. The panel’s length meets the requirements for the particular wall type and contributes toward the total amount of bracing required along its braced wall line in accordance with Sections AU106.11 and R602.10.1.

BUTTRESS. A mass set at an angle to, or bonded to a wall that it strengthens or supports.

CLAY. Inorganic soil with particle sizes less than 0.00008 inch (0.002 mm) having the characteristics of high to very high dry strength and medium
to high plasticity, used as the binder of other component materials in a mix of cob or of clay plaster.

CLAY SUBSOIL. Subsoil sourced directly from the earth, containing clay, sand, and silt, and not more than trace amounts of organic matter.

COB. A composite building material consisting of refined clay or clay subsoil wet-mixed with loose straw and sometimes sand. Also known as
monolithic adobe.

COB CONSTRUCTION. A wall system of layers or lifts of moist cob placed to create monolithic walls, typically without formwork.

DRY JOINT. The boundary between a layer of moist cob and a previously laid and significantly drier, non-malleable layer of cob that requires wetting to achieve bonding between the layers.

FINISH. Completed combination of materials on the face of a cob wall.

LIFT. A layer of installed cob.

LOAD-BEARING WALL. A cob wall that supports more than 100 pounds per linear foot (1459 N/m) of vertical load in addition to its own weight.

MONOLITHIC ADOBE. Synonymous with cob.

NATURAL COB. Cob not containing admixtures such as Portland cement, lime, asphalt emulsion, or oil. Synonymous with unstabilized cob.

NONSTRUCTURAL WALL. Walls other than load-bearing walls or shear walls.

PLASTER. Clay, soil-cement, gypsum, lime, clay-lime, cement-lime, or cement plaster as described in Section AU104.

SHEAR WALL. A cob wall designed and constructed to resist in-plane lateral seismic and wind forces in accordance with Section AU106.11. Synonymous with braced wall panel.

STABILIZED. Cob or other earthen material containing admixtures such as Portland cement, lime, asphalt emulsion, or oil, that are intended to help limit water absorption, stabilize volume, increase strength, and increase durability.

STRUCTURAL WALL. A wall that meets the definition for a load-bearing wall or shear wall.

STRAW. The dry stems of cereal grains after the seed heads have been removed.

UNSTABILIZED. A Cob or other earthen material that does not contain admixtures such as Portland cement, lime, asphalt emulsion, or oil.