ASTM E2556/E2556M-10(2022)

Standard Specification for Vapor Permeable Flexible Sheet Water-Resistive Barriers Intended for Mechanical Attachment

SCOPE
1.1 This specification is limited to vapor permeable flexible sheet materials which are intended to be mechanically attached and are generally installed behind the cladding system in exterior walls.  
1.2 This specification is limited to the evaluation of materials and does not address installed performance. Although the fastening practices (type of fastener, fastening schedule, etc.) may affect the installed function of these materials, they are not included in this specification.  
1.3 This specification does not address integration of the water-resistive barrier with other wall elements. The topic is addressed in more detail in Practice E2112 and Guide E2266.  
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 91.060.10 - Walls. Partitions. Facades
• Technical Committee: E06 - Performance of Buildings
• Drafting Committee: E06.55 - Performance of Building Enclosures

Relations

• Refers: ASTM E96/E96M-24 - Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials
• Effective Date: 01-Mar-2024
• Refers: ASTM E96/E96M-23 - Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials
• Effective Date: 15-Nov-2023
• Refers: ASTM E2112-19b - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 15-Apr-2019
• Refers: ASTM E2112-19a - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 01-Apr-2019
• Refers: ASTM E2112-19 - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 01-Jan-2019
• Refers: ASTM E2112-18b - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 15-Nov-2018
• Refers: ASTM E2112-18a - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 01-Nov-2018
• Refers: ASTM E2112-18 - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 01-Apr-2018
• Refers: ASTM D828-16 - Standard Test Method for Tensile Properties of Paper and Paperboard Using Constant-Rate-of-Elongation Apparatus
• Effective Date: 01-Nov-2016
• Refers: ASTM E2112-07(2016) - Standard Practice for Installation of Exterior Windows, Doors and Skylights
• Effective Date: 01-Jan-2016
• Refers: ASTM D4869/D4869M-16 - Standard Specification for Asphalt-Saturated Organic Felt Underlayment Used in Steep Slope Roofing
• Effective Date: 01-Jan-2016
• Refers: ASTM E96/E96M-15 - Standard Test Methods for Water Vapor Transmission of Materials
• Effective Date: 01-May-2015
• Refers: ASTM E631-15 - Standard Terminology of Building Constructions
• Effective Date: 01-Mar-2015
• Refers: ASTM D4869/D4869M-15 - Standard Specification for Asphalt-Saturated Organic Felt Underlayment Used in Steep Slope Roofing
• Effective Date: 01-Jan-2015
• Refers: ASTM E631-14 - Standard Terminology of Building Constructions
• Effective Date: 01-Nov-2014

Overview

ASTM E2556/E2556M-10(2022) is the international standard specification for vapor permeable flexible sheet water-resistive barriers (WRBs) intended for mechanical attachment behind the cladding of exterior wall systems. Developed by ASTM International, this standard outlines requirements for evaluating materials designed to provide secondary protection against water intrusion in building envelopes, thereby contributing to improved durability and energy efficiency in construction.

Designed with input from global building experts and based on principles set forth by the World Trade Organization Technical Barriers to Trade (TBT) Committee, ASTM E2556/E2556M-10(2022) promotes uniformity and quality in the selection and use of WRBs, minimizing the risk of moisture-related building failures.

Key Topics

• Scope of Standard:

  • Applies to vapor permeable, flexible sheet materials installed behind exterior wall cladding and mechanically attached to underlying structures.
  • Focuses on material property evaluation only; installation practices and overall system integration are addressed elsewhere.
  • Considers both SI and inch-pound units, but they must not be combined for compliance purposes.

• Classification:

  • Covers two categories:
    • Type I WRB: Meets base-level water resistance.
    • Type II WRB: Provides enhanced water resistance.
  • Materials are classified based on composition-felt-based, paper-based, or polymer-based barriers.

• Material Requirements:

  • Minimum performance levels for tensile strength, water resistance, water vapor transmission, and pliability.
  • Evaluation methods reference ASTM and other recognized test protocols.
  • Includes requirements for physical properties such as basis weight and roll weight.

• Testing and Marking:

  • Test specimens must meet water resistance and vapor permeability standards after both as-manufactured and aged (accelerated UV and moisture exposure) conditions.
  • Finished products require clear labeling and installation instructions detailing mechanical fastening, maximum weather exposure, and material lapping/taping.

• Limitations:

  • Does not address system-level performance or integration with related wall elements-these topics are addressed in standards such as ASTM E2112 and E2266.

Applications

ASTM E2556/E2556M-10(2022) assists manufacturers, architects, contractors, and building inspectors in:

• Specification and Selection: Enabling confident selection of water-resistive barrier products for use in residential, commercial, and industrial exterior wall assemblies.
• Quality Assurance: Providing minimum performance benchmarks for product development and procurement.
• Code Compliance: Satisfying building code requirements for moisture control and energy efficiency in wall systems through standardized evaluation.
• Documentation and Reporting: Supporting transparency in material properties, product labeling, and installation guidance for compliance and inspection purposes.
• Product Testing: Establishing standardized practices for measuring tensile strength, water resistance, vapor transmission, and durability after simulated aging.

Related Standards

Adherence and compatibility with related industry standards and guidelines is emphasized for comprehensive moisture management:

• ASTM D226/D226M – Specification for Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing.
• ASTM D779 – Test Method for Determining Water Vapor Resistance of Sheet Materials by Dry Indicator Method.
• ASTM D828 / D882 / D5034 – Various test methods for evaluating tensile properties of paper, plastic sheeting, and fabrics.
• ASTM E96/E96M – Methods for Water Vapor Transmission of Materials.
• ASTM E2112 – Practice for Installation of Exterior Windows, Doors, and Skylights.
• ASTM E2266 – Guide for Design and Construction of Low-Rise Frame Building Wall Systems to Resist Water Intrusion.
• ICC-ES AC38 – Acceptance Criteria for Water-Resistive Barriers.

Practical Value

Using ASTM E2556/E2556M-10(2022) supports:

• Enhanced building longevity through reliable water-resistive barrier selection.
• Reduced risk of mold, decay, and costly repairs by addressing water intrusion behind wall cladding.
• Assurance that vapor permeable WRBs are evaluated consistently and meet minimum industry benchmarks.
• Alignment with international best practices for moisture management and building envelope performance.

Keywords: vapor permeable barrier, water-resistive barrier, flexible sheet WRB, ASTM E2556, mechanical attachment, building envelope, exterior wall, moisture control, vapor transmission, building codes, construction standards.

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: E2556/E2556M −10 (Reapproved 2022)
Standard Specification for
Vapor Permeable Flexible Sheet Water-Resistive Barriers
Intended for Mechanical Attachment
ThisstandardisissuedunderthefixeddesignationE2556/E2556M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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 2. Referenced Documents
1.1 This specification is limited to vapor permeable flexible 2.1 ASTM Standards:
sheet materials which are intended to be mechanically attached D226/D226M Specification for Asphalt-Saturated Organic
and are generally installed behind the cladding system in Felt Used in Roofing and Waterproofing
exterior walls. D779 Test Method for Determining the Water Vapor Resis-
tance of Sheet Materials in Contact with Liquid Water by
1.2 This specification is limited to the evaluation of mate-
the Dry Indicator Method
rials and does not address installed performance.Although the
D828 Test Method for Tensile Properties of Paper and
fastening practices (type of fastener, fastening schedule, etc.)
PaperboardUsingConstant-Rate-of-ElongationApparatus
mayaffecttheinstalledfunctionofthesematerials,theyarenot
D882 Test Method for Tensile Properties of Thin Plastic
included in this specification.
Sheeting
1.3 This specification does not address integration of the
D4869/D4869M Specification for Asphalt-Saturated Or-
water-resistive barrier with other wall elements. The topic is
ganic Felt Underlayment Used in Steep Slope Roofing
addressed in more detail in Practice E2112 and Guide E2266.
D5034 TestMethodforBreakingStrengthandElongationof
1.4 The values stated in either SI units or inch-pound units Textile Fabrics (Grab Test)
E96/E96M Test Methods for Gravimetric Determination of
are to be regarded separately as standard. The values stated in
each system are not necessarily exact equivalents; therefore, to Water Vapor Transmission Rate of Materials
E631 Terminology of Building Constructions
ensure conformance with the standard, each system shall be
used independently of the other, and values from the two E1677 SpecificationforAirBarrier(AB)MaterialorAssem-
systems shall not be combined. blies for Low-Rise Framed Building Walls
E2112 Practice for Installation of Exterior Windows, Doors
1.5 This standard does not purport to address all of the
and Skylights
safety concerns, if any, associated with its use. It is the
E2128 Guide for Evaluating Water Leakage of Building
responsibility of the user of this standard to establish appro-
Walls
priate safety, health, and environmental practices and deter-
E2136 Guide for Specifying and Evaluating Performance of
mine the applicability of regulatory limitations prior to use.
Single Family Attached and Detached Dwellings—
1.6 This international standard was developed in accor-
Durability (Withdrawn 2022)
dance with internationally recognized principles on standard-
E2266 Guide for Design and Construction of Low-Rise
ization established in the Decision on Principles for the
Frame Building Wall Systems to Resist Water Intrusion
Development of International Standards, Guides and Recom-
G154 Practice for Operating Fluorescent Ultraviolet (UV)
mendations issued by the World Trade Organization Technical
Lamp Apparatus for Exposure of Nonmetallic Materials
Barriers to Trade (TBT) Committee.
1 2
This specification is under the jurisdiction of ASTM Committee E06 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Performance of Buildings and is the direct responsibility of Subcommittee E06.55 contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
on Performance of Building Enclosures. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2022. Published October 2022. Originally the ASTM website.
approved in 2009. Last previous edition approved in 2016 as E2556/E2556M – 10 The last approved version of this historical standard is referenced on
(2016). DOI: 10.1520/E2556_E2556M-10R22. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2556/E2556M − 10 (2022)
TABLE 1 Requirements for Water Resistive Barriers
Minimum Performance Requirements
Test Requirement Specimen Type Test Method
Type I Type II
Dry tensile strength (1) as manufactured Test Method D828 for paper 3500 N/m [20 lb/in.] minimum (machine and cross direction)
or dry breaking and and felt materials, or
force (choose 1) (2) aged in accordance Test Method D882 for 3500 N/m [20 lb/in.] minimum (machine and cross direction)
with A1.2 polymeric materials, or
Test Method D5034 (Grab 178 N [40 lbf] minimum (machine direction)
Method)
156 N [35 lbf] minimum (cross direction)
Water resistance (1) as manufactured Test Method D779, or 10 min minimum 60 min minimum
test (choose 1) and Water Resistance Ponding No water shall penetrate through not applicable
(2) aged in accordance Test (A1.1), or the membrane in 120 min
with A1.2 AATCC Test Method 127 not applicable No leakage is permitted to the underside
except that the specimens of any specimen in 5 h
shall be held at a
hydrostatic head of
55 cm [21.6 in.]
Water vapor as received Test Methods E96/E96M 290 ng/(Pa · s · m ) (5 perms) minimum
transmission test (Dessicant Method)
Pliability test as received see A1.3 The material shall not crack when bent over a 1.6 mm [ ⁄16 in.]
diameter mandrel at a temperature of 0 °C [32 °F]
2.2 Other Standards: 3.2.2 paper-based barrier, n—building papers composed
AATCC Test Method 127 Water Resistance: Hydrostatic predominantly of sulfate pulp fibers that comply with Federal
Pressure Test Specification UU-B-790a and that are intended for use as
CGSB CAN2-51.32.M77 Sheathing Membrane, Breather water-resistive barriers.
Type
3.2.3 polymer-based barrier, n—plastic sheet materials for
Federal Specification UU-B-790a Federal Specification
use as water-resistive barriers. These materials are generally
Building Paper, Vegetable Fiber (Kraft, Waterproofed,
referred to as a housewrap or building wrap. These materials
Water Repellent and Fire Resistant)
can be perforated with small holes or may be non-perforated,
TAPPI T-410 Test Method for Grammage of Paper and
composed of films or non-woven materials.
Paperboard (Weight Per Unit Area)
3.2.4 Type I WRB, n—water-resistive barrier with base-level
UBC Standard 14-1 Kraft Waterproof Building Paper
water resistance (see Table 1).
UBC Standard 32-1 Asphalt Saturated Rag Felt
3.2.5 Type II WRB, n—water-resistive barrier with enhanced
ICC-ES Acceptance Criteria AC38 for Water-Resistive Bar-
water resistance (see Table 1).
riers
3.2.6 Water-Resistive Barrier (WRB), n—a material that is
3. Terminology
intended to resist liquid water that has penetrated the cladding
system.
3.1 Definitions—For definitions of general terms related to
building construction used in this specification, refer to Termi-
NOTE 1—Wall assemblies often include two lines of defense against
nology E631.
rain water ingress. The cladding serves as the first line of defense and the
water-resistive barrier as the second line of defense
3.2 Definitions of Terms Specific to This Standard:
NOTE 2—Water-resistive barriers are sometimes referred to as weather
3.2.1 felt-based barrier, n—asphalt-saturated organic felts
resistant barriers or sheathing membranes.
that comply with Specification D226/D226M and are intended
4. Classification
for use as water-resistive barriers.
4.1 This specification covers vapor permeable flexible sheet
materials that are classified as Type I and Type II, which are
Available from American Association of Textile Chemists and Colorists
(AATCC), P.O. Box 12215, Research Triangle Park, NC 27709-2215, http:// determined by the degree of water resistance. The water-
www.aatcc.org.
resistive barrier material composition shall determine the
Available from Canadian General Standards Board (CGSB), 11 Laurier St.,
specific test method used to measure physical and mechanical
Phase III, Place du Portage, Gatineau, Quebec K1A0S5, Canada, http://www.tpsgc-
properties (see Table 1). Appendix X1 provides explanatory
pwgsc.gc.ca/ongc-cgsb.
Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
information on the physical and mechanical property test
Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
methods.
Available from Technological Association of the Pulp and Paper Industry
(TAPPI), 15 Technology Parkway South, Suite 115, Peachtree Corners, GA 30092,
5. Materials and Manufacture
http://www.tappi.org.
Uniform Building Code (UBC) information is available from International
5.1 Description of the material composition and structure
Code Council (ICC), 500 New JerseyAve., NW, 6th Floor, Washington, DC 20001,
shall be made available upon request.
http://www.iccsafe.org.
5.1.1 Descriptions of the materials shall include roll weight
Available from the ICC Evaluation Service (ICC-ES), 3060 Saturn Street, Suite
100, Brea, CA 92821, http://www.icc-es.org. and dimensions.
E2556/E2556M − 10 (2022)
5.1.2 Descriptions of the material composition shall include 8.2 The specimens shall be cut from the interior of the
linear density (basis weight). Basis weight shall be measured sample roll so that no specimen edge is nearer than 75 mm
using TAPPI T-410.
[3 in.] to the original sample edge.
6. Performance Requirements 8.3 Unless otherwise stated, all specimens to be tested shall
be conditioned for a minimum period of 40 h at 23 °C 62°C
6.1 All products seeking compliance with this specification
[73.4 °F 6 4 °F] and 50 % 6 5 % relative humidity (RH).
shallconformtotheminimumperformancerequirementslisted
in Table 1. Sampling and specimen size shall be in accordance
9. Marking and Labeling
with the referenced test methods. If not otherwise specified in
the referenced test method, a minimum of five specimens shall
9.1 The finished product shall be marked or labeled with
be tested and all specimens shall meet the minimum perfor-
product identification.
mance requirements.
9.2 Installation instructions shall be provided and shall
NOTE 3—The laboratory accelerated-ultraviolet (UV)/condensation ex-
include as a minimum the maximum weather exposure time
posure procedure specified in A1.2 is not intended to represent a specific
service exposure. It is a method of comparing the stability of materials allowed before cladding shall be installed, type of mechanical
under consistent laboratory exposure conditions.
fastener and minimum fastener spacing to attach the WRB to
the underlying structure, and lapping and taping requirements.
7. Other Requirements
This information shall be recorded and reported in any appli-
7.1 The material shall not adhere to itself to an extent that
cable test report or product rating.
will cause tearing or other damage on unrolling.
10. Keywords
8. Sampling
8.1 The product to be tested for conformance to this 10.1 building felt; building paper; building wrap; house-
wrap; sheathing membrane; water-resistive barrier; weather-
specification shall be taken directly from a randomly selected
roll which is representative of commercial product. resistive barrier
ANNEX
(Mandatory Information)
A1. TEST METHODS AND PRACTICES
A1.1 Water Resistance Ponding Test A1.1.4 Report:
A1.1.4.1 The report shall include the following:
A1.1.1 Scope—Thisisatestmethodintendedforevaluating
(1) The material and the side tested.
the water resistance of a Type I water-resistive barrier.
(2) The material sampling procedure used.
A1.1.2 Significance and Use—This method is for use with
(3) Pass/fail test results for each specimen tested.
water-resistive barriers. (4) Any modification to the method.
A1.1.5 Precision and Bias—No information is presented
A1.1.3 Procedure:
about either the precision or bias of this test method for
A1.1.3.1 Five specimens will be chosen at random from the
evaluating water resistance since the test result is nonquanti-
material supplied.
tative.
A1.1.3.2 A ring shall be constructed with a sample of the
membrane fastened between two 200 mm [8 in.] diameter
A1.2 Accelerated Aging (UV Exposure and Cyclic Drying/
aluminum rings using a rubber-type gasket. The membrane
Wetting)
shall be placed between the rings and cupped to permit a depth
A1.2.1 Scope—Thispracticeisusedtoconditionsamplesof
of 25 mm [1 in.] of water to be exposed to
2 2
water-resistive barriers to evaluate degradation of performance
16 000 mm [25 in. ] of its surface.
due to accelerated aging (UV exposure and dry/wet cycling).
A1.1.3.3 Distilled water shall be poured into the cylinder to
A1.2.2 Significance and Use—This practice is not intended
a depth of 25 mm [1 in.].
torepresentaserviceexposure.Itisamethodofcomparingthe
A1.1.3.4 The ring shall be raised by 250 mm [9.8 in.] above
stability of materials under consistent laboratory exposure
a sheet of plain kraft paper placed underneath the membrane to
conditions.
aid in monitoring any passage of water.
A1.2.3 Procedure:
A1.1.3.5 The membrane shall be maintained at constant
conditions of temperature (23 °C 6 2 °C [73.4 °F 6 4 °F]) and A1.2.3.1 Three samples shall be conditioned at 23 °C 6
RH (50 % 6 5 %) and be inspected at frequent intervals over 2 °C [73 °F 6 4 °F] and 50 % 6 5 % RH for a minimum of
a period of 2 h for water passage through the barrier material. 40 h. One sample shall be used for preparing unexposed
E2556/E2556M − 10 (2022)
specimens as a control. Two samples shall be exposed to UV A1.3.2 Significance and Use—This method is for use with
radiation,followedbyexposuretodryingandwettingcyclesin water-resistive barriers
accordance with A1.2.3.2 of this specification.
A1.3.3 Procedure:
A1.2.3.2 TwosamplesshallbeexposedtofluorescentUVA-
A1.3.3.1 Five specimens will be chosen at random from the
340 lamps in a fluorescent UV condensation apparatus oper-
material supplied.
ated in accordance with Practice G154, Cycle 1. The samples
shall be exposed for a duration of 2 weeks (336 h). UV
A1.3.3.2 Each specimen is bent 180° 6 5° over a 1.6 mm
radiation exposure shall be directed on the sample surfaces that
[ ⁄16 in.] mandrel in 2 s 61s.
will be exposed to sunlight in normal applications.
A1.3.3.3 The specimen and mandrel shall be maintained at
A1.2.3.3 Three specimens shall be cut from each of the
constant conditions of temperature (0 °C 6 2 °C [32 °F 6
samples that have been exposed to UV radiation and subjected
4 °F]) during the test procedure.
to further accelerated aging consisting of 25 cycles of drying
and soaking as follows: A1.3.4 Report:
(1) Oven drying at 49 °C [120 °F] for 3 h, with all surfaces
A1.3.4.1 The report shall include the following:
exposed.
(1) The material tested.
(2) Immersion in room-temperature (23 °C 6 2 °C [73 °F
(2) The material sampling procedure used.
6 4 °F]) water for 3 h, with all surfaces submerged.
(3) Observations of any visual cracking.
(3) After removal from the water, specimens shall be
(4) Any modification to the method.
blotted dry, then air-dried for 18 h at a 23.8 °C 6 2.8 °C [75 °F
6 5 °F] room temperature, with all surfaces exposed. A1.3.5 Precision and Bias—No information is presented
about either the precision or bias of this test method for
A1.3 Pliability
evaluating pliability since the test result is non-quantitative.
A1.3.1 Scope—This is the test method intended for evalu-
ating the pliability of a water-resistive barrier
APPENDIXES
(Nonmandatory Information)
X1. EXPLANATORY INFORMATION ON MECHANICAL AND PHYSICAL TEST METHODS
INTRODUCTION TENSILE STRENGTH
X1.1 There are a number of attributes of WRBs that should
X1.2 Although tensile strength does not directly measure
beconsideredintheirselection.Theseincludewaterresistance,
field performance of a WRB, it may indicate durability of
water vapor permeance, air resistance, durability compatibil-
materialsthataresubjectedtorepetitivestrainingandstressing.
itywithothermaterials,cost,installationchallenges,andmore.
The test methods used to test different materials differ primar-
TherearethreedifferentbasematerialsthatmakeupTypeIand
ily in the initial grip separation and the rate of strain of the test.
II water-resistive barriers. These base materials are felt, paper,
Test Method D828, the test method used for paper and
and polymeric materials. Within North America, each base
felt-based materials, prescribes an initial grip separation of
material has been historically evaluated using test methods that
180 mm [7 in.], and a separation (strain) rate of 25 mm/min
each respective base material industry recognized as most
[1 in.⁄min]. Test Method D882, used for polymeric materials,
applicable or appropriate for material characterization. These
prescribesaninitialgripseparation,andrateofstrainwhichare
test methods, while providing distinction with a given base
dependent on the percent elongation at break of the material.
material, are not always transferable between base material
RESISTANCE TO LIQUID WATER
types. Because the goal of a single set of test methods that can
be used to accurately evaluate the comparable critical perfor-
X1.3 The most fundamental property of a WRB is its
mance properties of allWRBs is not attainable at this time, this
resistance to the passage of liquid water, typically originating
specification is envisioned as a first step towards that goal.
as precipitation. Test methods commonly used for water
Appendix X1 describes additional information about the test
resistance were developed by the paper and textile industries
methods prescribed in this specification and their specificity to
for applications in such things as packaging and tarpaulins and
material composition.
bear limited resemblance to the function that WRBs play in
building-wall assemblies.
For more information, see Guide E2136. X1.3.1 Test methods and code requirements.
E2556/E2556M − 10 (2022)
X1.3.1.1 Water resistance of WRBs is commonly measured materialspecimen.Manufacturersofthesetypesofmembranes
in the United States by three test methods that are referenced, use a water column test. This involves sealing a sample of
directly or indirectly, in building codes. The three methods are
membrane to the base of a hollow column. Water is then
AATCC Test Method 127 (“hydrostatic pressure test”), some
poured into the column and the height of water over time is
variation of Test Method D779 – Water Resistance of Paper,
measured until water is observed on the dry side of the
Paperboard, and Other Sheet Materials by the Dry Indicator
membrane. The pressure at penetration is recorded.
Method (“boat test”), or the water resistance ponding test
Alternatively, the test can be run by maintaining a specific
developed by the Canadian Construction Materials Center
pressure of water above a sample and measuring the time for
(CCMC). WRBs evaluated by the CCMC water resistance
three drops of water to penetrate. ICC-ES Acceptance Criteria
ponding test are subjected to water for2hata depth of 25 mm
AC38 recognizes polymer-based WRBs that withstand a hy-
[1 in.].
drostatic pressure of 55 cm [22 in.] for5has equivalent to
X1.3.1.2 Codes used in the United States typically allow
having a 60 min rating by Test Method D779. Non-perforated
#15 asphalt saturated felt, conforming to Specification D226/
polymeric membranes generally perform better than building
D226M, prescriptively or Grade D asphalt treated kraft paper
papers in this test because of the small pores in the membrane
(10 min water resistance) under some variation of Test Method
and the better water-saturated strength of the membrane. Other
D779. Specification D226/D226M covers felts both with and
housewrap products, such as perforated polyolefin membranes,
without perforations, but only the non-perforated type is
usually fall somewhere between sheathing papers and non-
referenced in the IBC for use as a WRB. Other materials,
perforated polymeric membranes in terms of vapor permeabil-
including polymeric housewraps, are qualified by testing and
ity and resistance to liquid water (1). The properties of these
reporting under ICC-ES Acceptance Criteria AC38.
products will vary with the size and number of holes that are
X1.3.1.3 Felt and paper-based materials are tested for water
perforated though the base sheet. Resistance to liquid water of
resistance within this specification by Test Method D779 “the
perforated products will usually decrease as the vapor per-
boat test.” This test is performed by measuring the amount of
meance increases.
time it takes for water to diffuse through the material and affect
(2) The water resistance ponding test is described in
an indicator dye when the opposite side is in full contact with
CCMC Technical Guide for Sheathing, Membrane, Breather-
water. The 1997 UBC Standard 14-1, Kraft Waterproof Build-
Type, Masterformat Section 07102 (Technical Update July 7,
ing Paper, is based on Federal Specification UU-B-790a
1993), Section 6.4.5, in which a cylindrical bowl of the sample
(February 5, 1968). UBC Standard 14-1 does not describe the
material is filled with 25 mm [1 in.] of water and observed for
test protocol but simply states in a footnote “approved test
2 h. To pass the test, no seepage can be observed below the
methods shall be used.” The “boat test” from UU-B-790a was
sample. The Guide states that it is applicable to Breather-Type
incorporated into Test Method D779 and is referenced in
Sheathing Membranes, which are “polyethylene-based or
ICC-ESAcceptance CriteriaAC38 as one of the alternate tests
polypropylene-based, woven or non-woven.”
applicable to polymer-based water-resistive barriers. This test
(3) TheTestMethodD779waterresistancetestisalsoused
method is sensitive for both vapor and liquid-transfer through
to evaluate polymeric water resistive barriers as described in
thesample.AsstatedinSection4.1ofTestMethodD779,“The
X1.3.1.3.”
dry indicator used in this test method is so strongly hygro-
scopic it will change color in a moderate- to high-humidity
X1.3.2 Typical Test Results—Unexposed material: In a type
atmosphere without contacting liquid water. It will also change
of test where pressure is not a factor, asphalt-saturated felt
in contact with liquid water. This test method, therefore,
typically and significantly outperforms asphalt-saturated kraft
measures the combined effect of vapor and liquid transmission.
paper. With high pressures, asphalt-saturated kraft paper typi-
Fortesttimesuptoapproximately30s,liquidtransudationrate
cally slightly outperforms asphalt-saturated felt. This may be
is dominant and this test method can be considered to measure
because kraft paper has a tighter matrix than felt, thus
this property. As test times exceed 30 s, the influence of
performing better under pressure. Felt, however, has more
vapor-transmission rate increases and this test method cannot
asphalt, thus resisting migration of water longer under low
be regarded as a valid measure of liquid.”
pressure. It is well accepted that unperforated polymer WRBs
X1.3.1.4 Polymer-based materials are tested for water resis-
perform well under higher pressure compared to cellulose-
tance within this specification by three different tests; AATCC
based WRBs. However, the pressure at which even the least
Test Method 127 the “hydrostatic pressure test, the “water
water-resistant WRB failed a hydrostatic test 6000 Pa [0.87
resistance ponding test” and Test Method D779.
lbf/in. ] is equivalent to the force of a 320 kph [200 mph] wind
(1) The“hydrostaticpressuretest,”“watercolumntest,”or,
(2). Most low-rise residential windows are designed to with-
technically, AATCC Test Method 127, is listed in ICC-ES
stand a water-penetration pressure equivalent to a wind speed
Acceptance Criteria AC38 as an alternate test for polymer-
of 50 kph to 80 kph [30 mph to 50 mph].An 80 kph [50 mph]
based materials. This test measures the hydrostatic pressure
wind speed is equivalent to approximately 300 Pa [0.04
head at which three drops of water can be forced through a
lbf/in. ]. Relatively high performance of polymeric WRBs
The CGSB offers a Certification Program for Breather Type Sheathing
Membrane based on standard CGSB CAN2-51.32.M77—Sheathing, Membrane,
Breather Type. For information, contact the Conformity Assessment Officer at The boldface numbers in parentheses refer to a list of references at the end of
CGSB’s Certification Services - Products and Services. this standard.
E2556/E2556M − 10 (2022)
under high hydrostatic pressures may be impressive but not X1.4.1.3 To add even more confusion, Test Methods E96/
necessarily indicative of a property required to fulfill their E96Mincludestwobasicmethods(dessicantmethodandwater
intended function.
method)andtwovariationsincludeserviceconditionswithone
side wetted and service conditions with low humidity on one
X1.3.3 Resistance to Liquid Water: Aged Material—There
side and high humidity on the other. In accordance with Test
is no test information in the literature about comparative water
Methods E96/E96M: “Agreement should not be expected
resistance of WRBs after prolonged exposure to water, UV
light or to wet/dry cycling. Under ICC-ESAcceptance Criteria between results obtained by different methods.”
AC38, weathering by UVlight exposure and wet/dry cycling is
X1.4.1.4 Although WVT, is not the typical measure of
required of polymeric WRBs if they are tested for water
vapor permeance, both ICC-ESAcceptance CriteriaAC38 and
resistance using AATCC Test Method 127, Section 6.4.5 of
UBC Standard 14-1 require a minimum average WVT of
CCMC 07102 or Test Method D779. Current codes do not
“35 g⁄(m • 24h)” measured by Test Methods E96/E96M
require paper or felt based products to be evaluated after UV
Desiccant Method. The National Building Code of Canada
exposure or accelerated aging. Polymeric WRB manufacturers 2
requires permeance of >170 ng/Pa•s•m (3 perms). Witho
...