ASTM E2392/E2392M-23

Standard Guide for Design of Earthen Wall Building Systems

SIGNIFICANCE AND USE
5.1 Historical Overview—Earthen building systems have been used throughout the world for thousands of years. Adobe construction dates back to the walls of Jericho which were built around 8300 B.C. Many extant earthen structures have been functioning for hundreds of years. However, with the development of newer building materials, earthen building systems have fallen into disfavor in parts of the world where they were once commonly used. At the same time, earthen construction is experiencing a revival in the industrialized world, driven by a number of factors.  
5.2 Sustainability—As world population continues to rise and people continue to address basic shelter requirements, it becomes increasingly necessary to promote construction techniques with less life cycle impact on the earth. Earthen building systems are one type of technique that may have a favorable life cycle impact.  
5.3 Building Code Impact—Earthen building systems have historically not been engineered, but as of the late 20th Century it is for the first time in history possible to reliably apply rational structural design methods to earthen construction. A large number of earthen building codes, guidelines, and standards have appeared around the world over the past few decades, based upon a considerable amount of research and field observations regarding the seismic, thermal, and moisture durability performance of earthen structures. Some of those standards are:    
Australian Earth Building Handbook  
California Historical Building Code  
Chinese Building Standards  
Ecuadorian Earthen Building Standards  
German Earthen Building Standards  
Indian Earthen Building Standards  
International Building Code / provisions for adobe construction  
New Mexico Earthen Building Materials Code  
New Zealand Earthen Building Standards  
Peruvian Earthen Building Standards
This guide draws from those documents and the global experience to date in providing guidance on earthen construction ...
SCOPE
1.1 This standard provides guidance for earthen building systems, also called earthen construction, and addresses both technical requirements and considerations for sustainable development. Earthen building systems include adobe, rammed earth, cob, cast earth, and other earthen building technologies used as structural and non-structural wall systems.
Note 1: Other earthen building systems not specifically described in these guidelines, as well as domed, vaulted, and arched earthen structures as are common in many areas, can also make use of these guidelines when consistent with successful local building traditions or engineering judgment.  
1.1.1 There are many decisions in the design and construction of a building that can contribute to the maintenance of ecosystem components and functions for future generations. One such decision is the selection of products for use in the building. This guide addresses sustainability issues related to the use of earthen wall building systems.  
1.1.2 The considerations for sustainable development relative to earthen wall building systems are categorized as follows: materials (product feedstock), manufacturing process, operational performance (product installed), and indoor environmental quality (IEQ).  
1.1.3 The technical requirements for earthen building systems are categorized as follows: design criteria, structural and non-structural systems, and structural and non-structural components.  
1.2 Provisions of this guide do not apply to materials and products used in architectural cast stone (see Specification C1364).  
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.4 This standard does not purport to add...

General Information

• Status: Published
• Publication Date: 30-Nov-2023
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: E60 - Sustainability
• Drafting Committee: E60.01 - Buildings and Construction

Relations

• Replaces: ASTM E2392/E2392M-10(2016) - Standard Guide for Design of Earthen Wall Building Systems
• Effective Date: 01-Dec-2023

Overview

ASTM E2392/E2392M-23: Standard Guide for Design of Earthen Wall Building Systems provides comprehensive guidelines for the design and construction of earthen wall building systems. Developed by ASTM International, this standard addresses both technical and sustainability considerations for adobe, rammed earth, cob, cast earth, and other earthen construction technologies. These natural building systems are used for both structural and non-structural wall applications, offering an environmentally friendly alternative to conventional materials. The guide also draws upon historical knowledge and international codes to support the safe, effective use of earthen materials in modern construction.

Key Topics

• Historical Context: Earthen building systems have a legacy dating back thousands of years, with many examples of structures that remain functional today. Recent years have seen renewed interest in earthen construction, particularly due to sustainability concerns.
• Sustainable Development: Earthen construction supports sustainable development by utilizing local, renewable resources and minimizing environmental impact over the building's life cycle.
• Materials and Manufacturing:
  • Selection of appropriate soils (clay, sand, silt, gravel)
  • Use of organic and inorganic temper materials (e.g., straw, hair)
  • Stabilization techniques for enhanced durability
  • Types of plasters and coatings for maintenance and moisture protection
• Technical Design Criteria:
  • Structural and non-structural system requirements
  • Engineering considerations for seismic, thermal, and moisture durability
  • Appropriate use of stabilization methods such as cement, lime, or asphalt emulsion
  • Guidelines for foundations, wall assemblies, and reinforcement
• Operational Performance:
  • Energy efficiency provided by thermal mass
  • Indoor Environmental Quality (IEQ) assessment
  • Durability under various climate and use conditions

Applications

The ASTM E2392/E2392M-23 standard serves a global audience, including:

• Regions with Historic or Indigenous Earthen Traditions: Where earthen building is culturally embedded, this guide supports safer, more durable construction while preserving traditional techniques.
• Reviving and Emerging Markets: Ideal for areas with growing interest in sustainable and natural building, the standard assists engineers, architects, and code officials in integrating earthen construction with modern building codes and engineering practices.
• Sustainability-Focused Projects: Perfect for green building initiatives, earthen wall systems contribute to reduced life cycle impacts, enhanced IEQ, and responsible resource selection.
• Engineering and Code Development: Provides a basis for developing local standards, guidelines, and building codes supporting the mainstream acceptance of earthen construction.

Related Standards

This guide references and aligns with a variety of international and national standards to ensure a robust approach to earthen wall building systems:

• ASTM Standards
  • ASTM C1364: Specification for Architectural Cast Stone
  • ASTM D2487: Practice for Classification of Soils
  • ASTM E631: Building Construction Terminology
  • ASTM E2114: Sustainability Terminology
• ASCE Standards
  • ANSI/ASCE 7: Minimum Design Loads for Buildings and Other Structures
• New Zealand Standards
  • NZS 4297, NZS 4298, NZS 4299: Standards covering engineering, materials, and construction of earth buildings
• Other National and International Guidelines
  • Australian Earth Building Handbook
  • California Historical Building Code
  • Indian, Chinese, Ecuadorian, German, New Mexican, Peruvian, and New Zealand Earthen Building Standards
  • International Building Code (provisions for adobe construction)

By providing a framework for design and implementation rooted in global best practices and research, ASTM E2392/E2392M-23 supports the responsible, efficient, and durable use of earthen walls in contemporary construction.

Keywords: earthen wall building systems, ASTM E2392, adobe, rammed earth, cob construction, sustainable building, earthen architecture, energy efficiency, indoor environmental quality, natural building systems, building codes, sustainability, structural engineering, alternative building materials.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2392/E2392M − 23
Standard Guide for
Design of Earthen Wall Building Systems
This standard is issued under the fixed designation E2392/E2392M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This standard provides guidance for earthen building
responsibility of the user of this standard to establish appro-
systems, also called earthen construction, and addresses both
priate safety, health, and environmental practices and deter-
technical requirements and considerations for sustainable de-
mine the applicability of regulatory limitations prior to use.
velopment. Earthen building systems include adobe, rammed
1.5 This international standard was developed in accor-
earth, cob, cast earth, and other earthen building technologies
dance with internationally recognized principles on standard-
used as structural and non-structural wall systems.
ization established in the Decision on Principles for the
NOTE 1—Other earthen building systems not specifically described in
Development of International Standards, Guides and Recom-
these guidelines, as well as domed, vaulted, and arched earthen structures
mendations issued by the World Trade Organization Technical
as are common in many areas, can also make use of these guidelines when
Barriers to Trade (TBT) Committee.
consistent with successful local building traditions or engineering judg-
ment.
2. Referenced Documents
1.1.1 There are many decisions in the design and construc-
2.1 ASTM Standards:
tion of a building that can contribute to the maintenance of
C1364 Specification for Architectural Cast Stone
ecosystem components and functions for future generations.
D2487 Practice for Classification of Soils for Engineering
One such decision is the selection of products for use in the
Purposes (Unified Soil Classification System)
building. This guide addresses sustainability issues related to
E631 Terminology of Building Constructions
the use of earthen wall building systems.
E2114 Terminology for Sustainability
1.1.2 The considerations for sustainable development rela-
tive to earthen wall building systems are categorized as
2.2 ASCE Standards:
follows: materials (product feedstock), manufacturing process,
ANSI/ASCE 7 Minimum Design Loads for Buildings and
operational performance (product installed), and indoor envi-
Other Structures
ronmental quality (IEQ). 4
2.3 New Zealand Standards:
1.1.3 The technical requirements for earthen building sys-
NZS 4297:1998 Engineering Design of Earth Buildings,
tems are categorized as follows: design criteria, structural and
non-structural systems, and structural and non-structural com-
NZS 4298:1998 Materials and Workmanship for Earth
ponents.
Buildings, 1998
NZS 4299:1998 New Zealand Standard, Earth Buildings not
1.2 Provisions of this guide do not apply to materials and
products used in architectural cast stone (see Specification requiring Specific Design, 1998 (including amendment
#1, December 1999)
C1364).
1.3 The values stated in either SI units or inch-pound units
3. Terminology
are to be regarded separately as standard. The values stated in
3.1 Definitions:
each system may not be exact equivalents; therefore, each
3.1.1 For terms related to building construction, refer to
system shall be used independently of the other. Combining
Terminology E631.
values from the two systems may result in non-conformance
with the standard.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This guide is under the jurisdiction of ASTM Committee E60 on Sustainability Standards volume information, refer to the standard’s Document Summary page on
and is the direct responsibility of Subcommittee E60.01 on Buildings and Construc- the ASTM website.
tion. Available from American Society of Civil Engineers (ASCE), 1801 Alexander
Current edition approved Dec. 1, 2023. Published December 2023. Originally Bell Dr., Reston, VA 20191, http://www.asce.org.
approved in 2005. Last previous edition approved in 2016 as E2392/E2392M – 10 Available from Standards New Zealand, Ministry of Business, Innovation &
(2016). DOI: 10.1520/E2392_E2392M-23. Employment, 15 Stout Street, Wellington 6011, http://www.standards.govt.nz.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2392/E2392M − 23
3.1.2 For terms related to sustainability relative to the word atob, which means muck or sticky glob or atubah “the
performance of buildings, refer to Terminology E2114. Some brick.” In many other countries, the word “adobe” is
of these terms are reprinted here for ease of use. meaningless, and it is more accurate to say “earthen-brick.”
“Adobe architecture” also has different meanings in different
3.1.3 alternative agricultural products, n—bio-based indus-
places.
trial products (non-food, non-feed) manufactured from agricul-
tural materials and animal by-products.
3.2.2 asphalt emulsion, n—a thick liquid made by combin-
ing by-products of crude oil distillation with water and
3.1.4 ecosystem, n—a community of biological organisms
and their physical environment, functioning together as an proprietary surfactants.
interdependent unit within a defined area.
3.2.3 cast earth, n—a construction system utilizing a slurry
3.1.4.1 Discussion—For the purposes of this definition,
containing soil plus a chemical binder such as portland cement
humans, animals, plants, and microorganisms are individually
or calcined gypsum and water, which is sprayed against or
all considered biological organisms.
poured into forms similar to those used for cast-in-place
3.1.5 embodied energy, n—the energy used through the life concrete; also called poured earth.
cycle of a material or product to extract, refine, process, 3.2.3.1 Discussion—In the sprayed system, modern shot-
fabricate, transport, install, commission, utilize, maintain,
crete equipment is adapted to spray the wet earth mixture,
remove, and ultimately recycle or dispose of the substances which is usually stabilized earth.
comprising the item.
3.2.4 clay, n—inorganic soil with particle sizes less than
3.1.5.1 Discussion—The total energy which a product may
0.002 mm [0.00008 in.] having the characteristics of high to
be said to “contain” including all energy used in, inter alia,
very high dry strength and medium to high plasticity.
growing, extracting, transporting and manufacturing. The em-
3.2.4.1 Discussion—This size definition for clay, along with
bodied energy of a structure or system includes the embodied
those for silt, sand and gravel, is according to Practice D2487.
energy of its components plus the energy used in construction.
Other standards in the world have slightly different size
3.1.6 indoor environmental quality, IEQ, n—the condition
limitations.
or state of the indoor environment.
3.2.5 cob, n—a construction system utilizing moist earthen
3.1.6.1 Discussion—Aspects of IEQ include but are not
material stacked without formwork and lightly tamped into
limited to characteristics of the thermal, air, luminous and
place to form monolithic walls.
acoustic environment. Primary areas of concern in considering
3.2.5.1 Discussion—Reinforcing is often provided with or-
the IEQ usually relate to the health, comfort and productivity
ganic fibrous materials such as straw.
of the occupants within the indoor environment, but may also
3.2.6 earth, n—granular material derived from rock, usually
relate to potential damage to property, such as sensitive
with air voids and often with organic content (humus) (also
equipment or artifacts.
called soil).
3.1.7 renewable resource, n—a resource that is grown,
naturally replenished, or cleansed, at a rate which exceeds 3.2.7 earth, stabilized, n—earthen building mixtures to
depletion of the usable supply of that resource. which admixtures are added during the manufacturing process
to help limit water absorption, stabilize volume, increase
3.1.7.1 Discussion—A renewable resource can be exhausted
strength, and increase durability (see also stabilization).
if improperly managed. However, a renewable resource can
last indefinitely with proper stewardship. Examples include:
3.2.8 earth, unstabilized, n—earthen building mixtures that
trees in forests, grasses in grasslands, and fertile soil.
do not contain admixtures intended to help limit water
3.1.8 sustainability, n—the maintenance of ecosystem com- absorption, stabilize volume, increase strength, and increase
durability (see also stabilization).
ponents and functions for future generations.
3.1.9 sustainable development, n—development that meets 3.2.9 earthen construction, n—construction in which walls
the needs of the present without compromising the ability of and partitions are comprised primarily of earth.
future generations to meet their own needs.
3.2.9.1 Discussion—Roofs and other framing may be
wholly or partly of wood or other materials. Common earthen
3.2 Definitions of Terms Specific to This Standard:
construction systems go by many names, which sometimes
3.2.1 adobe, n—(1) (building product), unfired masonry
connote minor variations. Some of those names are:
units made of soil, water, and sometimes straw or other
adobe, or mud brick, earthen brick, banco, butabu, brique de terre
admixtures;
cast earth, or poured earth, earthcrete, sprayed earth
(2) (product feedstock), the soil/straw/admixtures mix that is
cob, or zabur, puddled mud, puddled earth
used to make adobe (1), (here also called earthen building
extruded earth block
pressed brick, or compressed earth brick/block (CEB)
mixtures or earthen material;
rammed earth, or pisé, tapial
(3) (building product), the earth plaster used for covering walls
sod, or turf, fale and divet
or ceilings, or both;
tire houses, also earth bags, earth tubes
wattle and daub, or quincha, jacal, barjareque, nyumba yo mata
(4) (structure), the building that is built of adobe (1), (3); and
(5) (building design), an architectural style of earthen construc-
3.2.10 energy effıcient, adj—refers to a product that requires
tion (see also 3.2.9).
less energy to manufacture or uses less energy when operating
3.2.1.1 Discussion—The word itself comes from an Arabic in comparison with a benchmark for energy use, or both.
E2392/E2392M − 23
3.2.10.1 Discussion—For example, the product may meet a zation or chemically stabilized. Chemical stabilization is
recognized benchmark, such as the EPA’s Energy Star Program achieved by the intermixture of cement, lime, gypsum, asphalt
standards. emulsion, or other materials with the soil before emplacement,
and curing as appropriate for the stabilizer and chemical
3.2.11 gravel, n—inorganic soil with particle sizes greater
reaction. Mechanical stabilization is achieved by compacting
than 4.75 mm [0.187 in.].
or compressing a plastic earth mixture, or containing earth in
3.2.12 horizon, n—distinctive layer of in situ soil having
permanent forms such as bags.
uniform qualities of color, texture, organic material, and
3.2.23 straw, n—an agricultural waste product that is the dry
obliteration of original rock material.
stems of cereal grains, or sometimes native grasses, after the
3.2.12.1 Discussion—In World Reference Base for Soil
seed heads have been removed.
Resources, by the Food and Agriculture Organization of the
United Nations, seven master horizons are recognized – H, O,
4. Summary of Guide
A, E, B, C, and R.
4.1 This guide identifies the principles of sustainability
3.2.13 loam, n—soil with a high percentage of organic
associated with earthen building systems. Additionally, it
material, particles are predominately silt size but range from
outlines technical issues associated with earthen building
clay size to sand size.
systems, identifying those that are similar to construction that
3.2.13.1 Discussion—Loams are usually good agricultural
is commonly used in the marketplace.
soils due to their nutritional organic content and their ability to
4.2 This guide is intended for use in framing decisions for
hold water. Loams should be avoided in earthen construction,
individual projects.
as the organic content is subject to biological decay and
volume change. Note that the word “loam” derives from the 4.3 This guide is intended for use in development of
German “lehm.” In Europe, “loam” and “lehm” usually have standards and building codes for earthen building systems.
an opposite meaning; that is, they connote earth with a very
5. Significance and Use
low organic content, ideal for building but not for agriculture.
5.1 Historical Overview—Earthen building systems have
3.2.14 material (product feedstock), n—refers to the sub-
been used throughout the world for thousands of years. Adobe
stances that are required for the manufacture or fabrication, or
construction dates back to the walls of Jericho which were built
both, of a building product.
around 8300 B.C. Many extant earthen structures have been
3.2.14.1 Discussion—Material resources include raw mate-
functioning for hundreds of years. However, with the develop-
rials and recycled content materials.
ment of newer building materials, earthen building systems
3.2.15 operational performance, n—refers to the function-
have fallen into disfavor in parts of the world where they were
ality of a product during its service life.
once commonly used. At the same time, earthen construction is
3.2.15.1 Discussion—Specific measures of operational per-
experiencing a revival in the industrialized world, driven by a
formance will vary depending upon the product. Aspects of
number of factors.
operational performance include: structural strength, durability,
5.2 Sustainability—As world population continues to rise
energy efficiency, and water efficiency.
and people continue to address basic shelter requirements, it
3.2.16 poured earth, n—see cast earth.
becomes increasingly necessary to promote construction tech-
3.2.17 pressed block, n—a block (or brick, or the construc-
niques with less life cycle impact on the earth. Earthen building
tion system using those blocks) that consists of earthen systems are one type of technique that may have a favorable
materials formed in a block mold by the mechanical compac-
life cycle impact.
tion of lightly moistened earth into a dense mass (also called
5.3 Building Code Impact—Earthen building systems have
compressed earth block, CEB).
th
historically not been engineered, but as of the late 20 Century
3.2.18 rammed earth, n—a construction system that consists
it is for the first time in history possible to reliably apply
of walls made from moist, sandy soil, or chemically stabilized
rational structural design methods to earthen construction. A
soil, which is tamped into forms (mechanically stabilized).
large number of earthen building codes, guidelines, and stan-
dards have appeared around the world over the past few
3.2.19 sand, n—inorganic soil with particle sizes ranging
decades, based upon a considerable amount of research and
from 0.75 mm to 4.75 mm [0.03 in. to 0.19 in.].
field observations regarding the seismic, thermal, and moisture
3.2.20 silt, n—inorganic soil with particle sizes ranging
durability performance of earthen structures. Some of those
from 0.002 mm to 0.75 mm [0.00008 in. to 0.03 in.] having the
standards are:
characteristics of low dry strength, low plasticity, and little
Australian Earth Building Handbook
dilatancy.
California Historical Building Code
Chinese Building Standards
3.2.21 soil, n—see earth,
Ecuadorian Earthen Building Standards
3.2.22 stabilization, n—modification of soils to limit water German Earthen Building Standards
Indian Earthen Building Standards
absorption, stabilize volume, increase strength, and increase
International Building Code / provisions for adobe construction
durability, or some combination of these.
New Mexico Earthen Building Materials Code
3.2.22.1 Discussion—For the purposes of this guide, refer- New Zealand Earthen Building Standards
Peruvian Earthen Building Standards
ence to “stabilization” or “stabilized” means chemical stabili-
E2392/E2392M − 23
This guide draws from those documents and the global tures. Cement plaster, which is considerably less vapor-
experience to date in providing guidance on earthen construc- permeable than earthen plaster, can trap moisture, resulting in
tion to engineers, building officials, and regulatory agencies. saturation and deterioration of unstabilized earth wall systems.
For this reason, the use of cement plaster over unstabilized
5.4 Audience—There are two primary and sometimes over-
earth is strongly discouraged.
lapping markets for earthen construction and for this guide:
6.1.3.3 Lime Plaster—Lime plaster is a mixture of hydrated
5.4.1 Areas with Historical or Indigenous Earthen Building
lime and sand that is much more compatible with unstabilized
Traditions—In places where earthen architecture is embedded
earth than cement plaster in terms of vapor permeability,
in the culture, or there is little practical or economical access to
coefficient of temperature change, and stiffness. Lime plaster
other building systems, this guide can set a framework for
has a long and successful history of use over indigenous
increasing life safety and building durability.
earthen building systems in various cultures. Successful appli-
5.4.2 Areas with a Nascent or Reviving Interest in Earthen
cation of lime plaster over unstabilized earth does require some
Architecture—In places where earth is sometimes chosen over
manner of mechanical locking, such as by scoring the earth
other options as the primary structural material, this guide
surface, and careful application of the lime in progressive
provides a framework for codification and engineering design.
layers.
6. Considerations for Sustainable Development and
6.2 Manufacturing Process:
Durability
6.2.1 Manufacturing—The manufacturing process of creat-
6.1 Materials (Product Feedstock)—Materials of earthen ing a building product includes not only the process to produce
manufacturing, but also fabrication and distribution proce-
building systems include clay soil and inorganic or organic
tempering materials. Silt, sand, and gravel are commonly used dures. The manufacture of unstabilized earthen building mate-
rials is substantially more energy efficient per unit volume than
inorganic tempers and straw, hair, and chaff are commonly
the manufacture of fired-clay masonry like brick, terra-cotta, or
used organic tempers. Soils may be stabilized, using such
structural clay tile, or the manufacture of cement-based sys-
materials as cement, asphalt emulsion, calcined gypsum or
tems like concrete masonry, precast concrete, or cast-in-place
cactus juice, or may be unstabilized. Systems may be finished
concrete. Stabilized earthen materials that use Portland cement,
with plaster or left unfinished.
lime, asphalt emulsion, or calcined gypsum are less energy
6.1.1 Soil—Soils for earthen building systems are a mixture
efficient to manufacture per unit volume than similar unstabi-
of a binder (clay), and temper soils of silt, sand, and gravel.
lized materials, but are generally more energy efficient to
These mixtures may be naturally occurring local soils or
manufacture than cement-based concrete materials.
engineered by mixing different soils. Sources for the soils
include on-site horizons, by-products of sand and gravel
6.2.2 Fabrication—In the fabrication of earthen
quarrying, and alluvial deposits. Some clays are highly expan- construction, a clay binder is tempered with inorganic or
sive (montmorillonites) or moderately expansive (illites) when
organic materials, or both, to reduce shrinkage and cracking,
wetted, and thus problematic for earthen construction. Ideally,
and to increase strength and workability. Soils may be unsta-
a non-expansive kaolinite clay should be used. The intermix-
bilized or may be stabilized. Stabilizing is done to increase
ture of small amounts of lime, bitumen, or cement will negate
durability and strength. Placement of adobe and pressed-block
the expansive properties of swelling clays, but by the same
systems is similar to the placement of fired-clay and concrete
chemical mechanism negate the binding and other beneficial
masonry units systems in that manufactured units are hand
properties of the clay. Stabilizing binders should thus generally
stacked upon one another to produce structures. Where the
be used only when there is no other viable strategy for meeting
fabrication of these systems differs is in the mortar used to
the project requirements. Care should be taken to avoid adverse
bond the manufactured units, or the firing of the units, or both.
effects on the capacity for food production when considering
Fired-clay and concrete masonry systems use mortars contain-
the use of loams and other soils that are suitable for agricultural ing Portland cement, proprietary masonry cements, and mortar
purposes.
cements, and lime putty which use substantially more energy in
6.1.2 Straw—Straw, being dry and having no seed heads is their manufacturing processes than unstabilized earthen build-
more durable in earthen building systems than hay which
ing mortars and, to a lesser degree, stabilized earthen building
contains seed heads. Straw is an agricultural waste product that mortars. Fabrication of rammed earth is similar to the fabrica-
is typically not used for productive end use; therefore, it is
tion of cast-in-place concrete systems in that formwork is
considered an alternative agricultural product and a renewable required. Formwork is usually temporary wood, steel, fiber-
resource when used in earthen building systems.
glass or earth construction built to give the desired shape and
6.1.3 Plaster—“Plaster” is a material applied to the exposed size to the completed structure. The formwork is removed
surfaces of earthen building systems to improve durability and
before full curing of the material and can be reused or recycled
modify appearance. depending upon the material used. Where the systems differ is
6.1.3.1 Earth (or Clay) Plaster—Earth plaster is a mixture
in the amount of labor required to place the materials in the
of clay, silt, sand, and water. Fibrous tempering materials are formwork. Cast-in-place concrete, which is continuously
typically added.
poured into place until the desired height or thickness is
6.1.3.2 Cement Plaster—Cement plaster is a mixture of obtained, requires less onsite labor than rammed earth, which
cement, sand and water; the mixture may also include is placed into the form in short layers called lifts and
pozzolans, lime, pigments, glass fibers, and proprietary admix- compacted after each lift. Fabrication by the cob method
E
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2392/E2392M − 10 (Reapproved 2016) E2392/E2392M − 23
Standard Guide for
Design of Earthen Wall Building Systems
This standard is issued under the fixed designation E2392/E2392M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This standard provides guidance for earthen building systems, also called earthen construction, and addresses both technical
requirements and considerations for sustainable development. Earthen building systems include adobe, rammed earth, cob, cast
earth, and other earthen building technologies used as structural and non-structural wall systems.
NOTE 1—Other earthen building systems not specifically described in these guidelines, as well as domed, vaulted, and arched earthen structures as are
common in many areas, can also make use of these guidelines when consistent with successful local building traditions or engineering judgment.
1.1.1 There are many decisions in the design and construction of a building that can contribute to the maintenance of ecosystem
components and functions for future generations. One such decision is the selection of products for use in the building. This guide
addresses sustainability issues related to the use of earthen wall building systems.
1.1.2 The considerations for sustainable development relative to earthen wall building systems are categorized as follows:
materials (product feedstock), manufacturing process, operational performance (product installed), and indoor environmental
quality (IEQ).
1.1.3 The technical requirements for earthen building systems are categorized as follows: design criteria, structural and
non-structural systems, and structural and non-structural components.
1.2 Provisions of this guide do not apply to materials and products used in architectural cast stone (see Specification C1364).
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
This guide is under the jurisdiction of ASTM Committee E60 on Sustainability and is the direct responsibility of Subcommittee E60.01 on Buildings and Construction.
Current edition approved Sept. 1, 2016Dec. 1, 2023. Published September 2016December 2023. Originally approved in 2005. Last previous edition approved in 20102016
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as E2392/E2392M – 10 (2016). . DOI: 10.1520/E2392_E2392M-10R16.10.1520/E2392_E2392M-23.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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2. Referenced Documents
2.1 ASTM Standards:
C1364 Specification for Architectural Cast Stone
D2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)
E631 Terminology of Building Constructions
E2114 Terminology for Sustainability
2.2 ASCE Standards:
ANSI/ASCE 7 Minimum Design Loads for Buildings and Other Structures
2.3 New Zealand Standards:
NZS 4297:1998 Engineering Design of Earth Buildings, 1998
NZS 4298:1998 Materials and Workmanship for Earth Buildings, 1998
NZS 4299:1998 New Zealand Standard, Earth Buildings not requiring Specific Design, 1998 (including amendment #1,
December 1999)
3. Terminology
3.1 Definitions:
3.1.1 For terms related to building construction, refer to Terminology E631.
3.1.2 For terms related to sustainability relative to the performance of buildings, refer to Terminology E2114. Some of these terms
are reprinted here for ease of use.
3.1.3 alternative agricultural products, n—bio-based industrial products (non-food, non-feed) manufactured from agricultural
materials and animal by-products.
3.1.4 biodegradable, adj—capable of decomposing under natural conditions into elements found in nature.
3.1.5 biodiversity, n—the variability among living organisms from all sources including: terrestrial, marine and other aquatic
ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of
ecosystems.
3.1.4 ecosystem, n—a community of biological organisms and their physical environment, functioning together as an
interdependent unit within a defined area.
3.1.4.1 Discussion—
For the purposes of this definition, humans, animals, plants, and microorganisms are individually all considered biological
organisms.
3.1.5 embodied energy, n—the energy used through the life cycle of a material or product to extract, refine, process, fabricate,
transport, install, commission, utilize, maintain, remove, and ultimately recycle or dispose of the substances comprising the item.
3.1.5.1 Discussion—
The total energy which a product may be said to “contain” including all energy used in, inter alia, growing, extracting, transporting
and manufacturing. The embodied energy of a structure or system includes the embodied energy of its components plus the energy
used in construction.
3.1.6 indoor environmental quality, IEQ, n—the condition or state of the indoor environment.
3.1.6.1 Discussion—
Aspects of IEQ include but are not limited to characteristics of the thermal, air, luminous and acoustic environment. Primary areas
of concern in considering the IEQ usually relate to the health, comfort and productivity of the occupants within the indoor
environment, but may also relate to potential damage to property, such as sensitive equipment or artifacts.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http://www.asce.org.
Available from Standards New Zealand, Ministry of Business, Innovation & Employment, 15 Stout Street, Wellington 6011, http://www.standards.govt.nz.
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3.1.7 renewable resource, n—a resource that is grown, naturally replenished, or cleansed, at a rate which exceeds depletion of the
usable supply of that resource.
3.1.7.1 Discussion—
A renewable resource can be exhausted if improperly managed. However, a renewable resource can last indefinitely with proper
stewardship. Examples include: trees in forests, grasses in grasslands, and fertile soil.
3.1.8 sustainability, n—the maintenance of ecosystem components and functions for future generations.
3.1.9 sustainable development, n—development that meets the needs of the present without compromising the ability of future
generations to meet their own needs.
3.1.12 toxicity, n—the property of a material, or combination of materials, to adversely affect organisms.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 adobe, n—(1) (building product), unfired masonry units made of soil, water, and sometimes straw or other admixtures;
(2) (product feedstock), the soil/straw/admixtures mix that is used to make adobe (1), (here also called earthen building mixtures
or earthen material;
(3) (building product), the earth plaster used for covering walls or ceilings, or both;
(4) (structure), the building that is built of adobe (1), (3); and
(5) (building design), an architectural style of earthen construction (see also 3.2.9).
3.2.1.1 Discussion—
The word itself comes from an Arabic word atob, which means muck or sticky glob or atubah “the brick.” In many other countries,
the word “adobe” is meaningless, and it is more accurate to say “earthen-brick.” “Adobe architecture” also has different meanings
in different places.
3.2.2 asphalt emulsion, n—a thick liquid made by combining by-products of crude oil distillation with water and proprietary
surfactants.
3.2.3 cast earth, n—a construction system utilizing a slurry containing soil plus a chemical binder such as portland cement or
calcined gypsum and water, which is sprayed against or poured into forms similar to those used for cast-in-place concrete; also
called poured earth.
3.2.3.1 Discussion—
In the sprayed system, modern shotcrete equipment is adapted to spray the wet earth mixture, which is usually stabilized earth.
3.2.4 clay, n—inorganic soil with particle sizes less than 0.002 mm [0.00008 in.] having the characteristics of high to very high
dry strength and medium to high plasticity.
3.2.4.1 Discussion—
This size definition for clay, along with those for silt, sand and gravel, is according to Practice D2487. Other standards in the world
have slightly different size limitations.
3.2.5 cob, n—a construction system utilizing moist earthen material stacked without formwork and lightly tamped into place to
form monolithic walls.
3.2.5.1 Discussion—
Reinforcing is often provided with organic fibrous materials such as straw.
3.2.6 earth, n—granular material derived from rock, usually with air voids and often with organic content (humus) (also called
soil).
3.2.7 earth, stabilized, n—earthen building mixtures to which admixtures are added during the manufacturing process to help limit
water absorption, stabilize volume, increase strength, and increase durability (see also stabilization).
3.2.8 earth, unstabilized, n—earthen building mixtures that do not contain admixtures intended to help limit water absorption,
stabilize volume, increase strength, and increase durability (see also stabilization).
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3.2.9 earthen construction, n—construction in which walls and partitions are comprised primarily of earth.
3.2.9.1 Discussion—
Roofs and other framing may be wholly or partly of wood or other materials. Common earthen construction systems go by many
names, which sometimes connote minor variations. Some of those names are:
adobe, or mud brick, earthen brick, banco, butabu, brique de terre
cast earth, or poured earth, earthcrete, sprayed earth
cob, or zabur, puddled mud, puddled earth
extruded earth block
pressed brick, or compressed earth brick/block (CEB)
rammed earth, or pisé, tapial
sod, or turf, fale and divet
tire houses, also earth bags, earth tubes
wattle and daub, or quincha, jacal, barjareque, nyumba yo mata
3.2.10 energy effıcient, adj—refers to a product that requires less energy to manufacture or uses less energy when operating in
comparison with a benchmark for energy use, or both.
3.2.10.1 Discussion—
For example, the product may meet a recognized benchmark, such as the EPA’s Energy Star Program standards.
3.2.11 gravel, n—inorganic soil with particle sizes greater than 4.75 mm [0.187 in.].
3.2.12 horizon, n—distinctive layer of in situ soil having uniform qualities of color, texture, organic material, and obliteration of
original rock material.
3.2.12.1 Discussion—
In World Reference Base for Soil Resources, by the Food and Agriculture Organization of the United Nations, seven master
horizons are recognized – H, O, A, E, B, C, and R.
3.2.13 loam, n—soil with a high percentage of organic material, particles are predominately silt size but range from clay size to
sand size.
3.2.13.1 Discussion—
Loams are usually good agricultural soils due to their nutritional organic content and their ability to hold water. Loams should be
avoided in earthen construction, as the organic content is subject to biological decay and volume change. Note that the word “loam”
derives from the German “lehm.” In Europe, “loam” and “lehm” usually have an opposite meaning; that is, they connote earth with
a very low organic content, ideal for building but not for agriculture.
3.2.14 material (product feedstock), n—refers to the substances that are required for the manufacture or fabrication, or both, of
a building product.
3.2.14.1 Discussion—
Material resources include raw materials and recycled content materials.
3.2.15 moisture wicking—the capillary uptake of water from foundation soil or precipitation.
3.2.15.1 Discussion—
Moisture wicking can result in saturation of adobe with an accompanying decrease in strength and durability.
3.2.15 operational performance, n—refers to the functionality of a product during its service life.
3.2.15.1 Discussion—
Specific measures of operational performance will vary depending upon the product. Aspects of operational performance include:
structural strength, durability, energy efficiency, and water efficiency.
3.2.16 poured earth, n—see cast earth.
3.2.17 pressed block, n—a block (or brick, or the construction system using those blocks) that consists of earthen materials formed
in a block mold by the mechanical compaction of lightly moistened earth into a dense mass (also called compressed earth block,
CEB).
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3.2.18 rammed earth, n—a construction system that consists of walls made from moist, sandy soil, or chemically stabilized soil,
which is tamped into forms (mechanically stabilized).
3.2.19 sand, n—inorganic soil with particle sizes ranging from 0.75 to 4.75 mm [0.03 to 0.19 in.].0.75 mm to 4.75 mm [0.03 in.
to 0.19 in.].
3.2.20 silt, n—inorganic soil with particle sizes ranging from 0.002 to 0.75 mm [0.00008 to 0.03 in.] 0.002 mm to 0.75 mm
[0.00008 in. to 0.03 in.] having the characteristics of low dry strength, low plasticity, and little dilatancy.
3.2.21 soil, n—see earth,
3.2.22 stabilization, n—modification of soils to limit water absorption, stabilize volume, increase strength, and increase durability,
or some combination of these.
3.2.22.1 Discussion—
For the purposes of this guide, reference to “stabilization” or “stabilized” means chemical stabilization or chemically stabilized.
Chemical stabilization is achieved by the intermixture of cement, lime, gypsum, asphalt emulsion, or other materials with the soil
before emplacement, and curing as appropriate for the stabilizer and chemical reaction. Mechanical stabilization is achieved by
compacting or compressing a plastic earth mixture, or containing earth in permanent forms such as bags.
3.2.23 straw, n—an agricultural waste product that is the dry stems of cereal grains, or sometimes native grasses, after the seed
heads have been removed.
3.2.25 straw-clay, n—a construction system that consists of clay slip mixed with straw, of which straw makes up a high percentage
by volume.
3.2.25.1 Discussion—
Other fibers such as wood shavings or paper are sometimes used. This system is well suited for manufacturing blocks and in situ
insulating wall panels.
4. Summary of Guide
4.1 This guide identifies the principles of sustainability associated with earthen building systems. Additionally, it outlines technical
issues associated with earthen building systems, identifying those that are similar to construction that is commonly used in the
marketplace.
4.2 This guide is intended for use in framing decisions for individual projects.
4.3 This guide is intended for use in development of standards and building codes for earthen building systems.
5. Significance and Use
5.1 Historical Overview—Earthen building systems have been used throughout the world for thousands of years. Adobe
construction dates back to the walls of Jericho which waswere built around 8300 B.C. Many extant earthen structures have been
functioning for hundreds of years. However, with the development of newer building materials, earthen building systems have
fallen into disfavor in parts of the world where they were once commonly used. At the same time, earthen construction is
experiencing a revival in the industrialized world, driven by a number of factors.
5.2 Sustainability—As world population continues to rise and people continue to address basic shelter requirements, it becomes
increasingly necessary to promote construction techniques with less life cycle impact on the earth. Earthen building systems are
one type of technique that may have a favorable life cycle impact.
th
5.3 Building Code Impact—Earthen building systems have historically not been engineered, but as of the late 20th20 Century
it is for the first time in history possible to reliably apply rational structural design methods to earthen construction. A large number
of earthen building codes, guidelines, and standards have appeared around the world over the past few decades, based upon a
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considerable amount of research and field observations regarding the seismic, thermal, and moisture durability performance of
earthen structures. Some of those standards are:
Australian Earth Building Handbook
California Historical Building Code
Chinese Building Standards
Ecuadorian Earthen Building Standards
German Earthen Building Standards
Indian Earthen Building Standards
International Building Code / provisions for adobe construction
New Mexico Earthen Building Materials Code
New Zealand Earthen Building Standards
Peruvian Earthen Building Standards
This guide draws from those documents and the global experience to date in providing guidance on earthen construction to
engineers, building officials, and regulatory agencies.
5.4 Audience—There are two primary and sometimes overlapping markets for earthen construction and for this guide:
5.4.1 Areas with Historical or Indigenous Earthen Building Traditions—In places where earthen architecture is embedded in the
culture, or there is little practical or economical access to other building systems, this guide can set a framework for increasing
life safety and building durability.
5.4.2 Areas with a Nascent or Reviving Interest in Earthen Architecture—In places where earth is sometimes chosen over other
options as the primary structural material, this guide provides a framework for codification and engineering design.
6. Considerations for Sustainable Development and Durability
6.1 Materials (Product Feedstock)—Materials of earthen building systems include clay soil and inorganic or organic tempering
materials. Silt, sand, and gravel are commonly used inorganic tempers and straw, hair, and chaff are commonly used organic
tempers. Soils may be stabilized, using such materials as cement, asphalt emulsion, calcined gypsum or cactus juice, or may be
unstabilized. Systems may be finished with plaster or left unfinished.
6.1.1 Soil—Soils for earthen building systems are a mixture of a binder (clay), and temper soils of silt, sand, and gravel. These
mixtures may be naturally occurring local soils or engineered by mixing different soils. Sources for the soils include on-site
horizons, by-products of sand and gravel quarrying, and alluvial deposits. Some clays are highly expansive (montmorillonites) or
moderately expansive (illites) when wetted, and thus problematic for earthen construction. Ideally, a non-expansive kaolinite clay
should be used. The intermixture of small amounts of lime, bitumen, or cement will negate the expansive properties of swelling
clays, but by the same chemical mechanism negate the binding and other beneficial properties of the clay. Stabilizing binders
should thus generally be used only when there is no other viable strategy for meeting the project requirements. Care should be
taken to avoid adverse affectseffects on the capacity for food production when considering the use of loams and other soils that
are suitable for agricultural purposes.
6.1.2 Straw—Straw, being dry and having no seed heads is more durable in earthen building systems than hay which contains seed
heads. Straw is an agricultural waste product that is typically not used for productive end use; therefore, it is considered an
alternative agricultural product and a renewable resource when used in earthen building systems.
6.1.3 Plaster—“Plaster” is a material applied to the exposed surfaces of earthen building systems to improve durability and modify
appearance.
6.1.3.1 Earth (or clay)Clay) Plaster—Earth plaster is a mixture of clay, silt, sand, and water. Fibrous tempering materials are
typically added.
6.1.3.2 Cement Plaster—Cement plaster is a mixture of cement, sand and water; the mixture may also include pozzolans, lime,
pigments, glass fibers, and proprietary admixtures. Cement plaster, which is considerably less vapor-permeable than earthen
plaster, can trap moisture, resulting in saturation and deterioration of unstabilized earth wall systems. For this reason, the use of
cement plaster over unstabilized earth is strongly discouraged.
6.1.3.3 Lime Plaster—Lime plaster is a mixture of hydrated lime and sand that is much more compatible with unstabilized earth
than cement plaster in terms of vapor permeability, coefficient of temperature change, and stiffness. Lime plaster has a long and
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successful history of use over indigenous earthen building systems in various cultures. Successful application of lime plaster over
unstabilized earth does require some manner of mechanical locking, such as by scoring the earth surface, and careful application
of the lime in progressive layers.
6.2 Manufacturing Process:
6.2.1 Manufacturing—The manufacturing process of creating a building product includes not only the process to produce
manufacturing, but also fabrication and distribution procedures. The manufacture of unstabilized earthen building materials is
substantially more energy efficient per unit volume than the manufacture of fired-clay masonry like brick, terra-cottaterra-cotta, or
structural clay tile, or the manufacture of cement-based systems like concrete masonry, precast concrete, or cast-in-place
concreteconcrete. Stabilized earthen materials that use Portland cement, lime, asphalt emulsion, or calcined gypsum are less energy
efficient to manufacture per unit volume than similar unstabilized materials, but are generally more energy efficient to manufacture
than cement-based concrete materials.
6.2.2 Fabrication—In the fabrication of earthen construction, a clay binder is tempered with inorganic or organic materials, or
both, to reduce shrinkage and cracking, and to increase strength and workability. Soils may be unstabilized or may be stabilized.
Stabilizing is done to increase durability and strength. Placement of adobe and pressed-block systems is similar to the placement
of fired-clay and concrete masonry units systems in that manufactured units are hand stacked upon one another to produce
structures. Where the fabrication of these systems differs is in the mortar used to bond the manufactured units, or the firing of the
units, or both. Fired-clay and concrete masonry systems use mortars containing Portland cement, proprietary masonry cements, and
mortar cements, and lime putty which use substantially more energy in their manufacturing processes than unstabilisedunstabilized
earthen building mortars and, to a lesser degree, stabilized earthen building mortars. Fabrication of rammed earth is similar to the
fabrication of cast-in-place concrete systems in that formwork is required.
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