ASTM D1970/D1970M-21

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Designation: D1970/D1970M − 20 D1970/D1970M − 21
Standard Specification for
Self-Adhering Polymer Modified Bituminous Sheet Materials
Used as Steep Roofing Underlayment for Ice Dam
Protection
This standard is issued under the fixed designation D1970/D1970M; 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 specification covers polymer modified bituminous sheet materials intended for use as underlayment on roof eaves, or
valleys, or both, to prevent leakage of shingle, tile, or metal roofs from water back-up due to ice dams.
1.2 These underlayment sheets have a sticky adhesive layer which is exposed by removal of a protective sheet. The top surface
is suitable to work on during the application of the exposed roofing.
1.3 Table of Contents:
Section
Scope 1
Referenced Documents 2
Terminology 3
Workmanship, Finish, and Appearance 4
Physical Requirements 5
Sampling 6
Test Methods 7
Conditioning 7.1
Thickness 7.2
Maximum Load and Elongation at Break 7.3
Adhesion to Plywood 7.4
Thermal Stability 7.5
Flexibility at –29 °C [–20 °F] 7.6
Tear Resistance 7.7
Moisture Vapor Permeability 7.8
Capability to Seal Around Nail 7.9
(Head of Water Test)
Waterproof Integrity of Side Lap Seam 7.10
(Head of Water Test)
Inspection 8
Rejection and Rehearing 9
Packaging and Package Marking 10
Keywords 11
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
This specification is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.02 on Steep
Roofing Products and Assemblies.
Current edition approved July 15, 2020May 1, 2021. Published July 2020June 2021. Originally approved in 1990. Last previous edition approved in 20192020 as
D1970/D1970M – 19.D1970/D1970M – 20. DOI: 10.1520/D1970_D1970M-20.10.1520/D1970_D1970M-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1970/D1970M − 21
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 nonconformance with the standard.
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.
2. Referenced Documents
2.1 ASTM Standards:
D228/D228M Test Methods for Sampling, Testing, and Analysis of Asphalt Roll Roofing, Cap Sheets, and Shingles Used in
Roofing and Waterproofing
D903 Test Method for Peel or Stripping Strength of Adhesive Bonds
D1079 Terminology Relating to Roofing and Waterproofing
D1204 Test Method for Linear Dimensional Changes of Nonrigid Thermoplastic Sheeting or Film at Elevated Temperature
D2523/D2523M Practice for Testing Load-Strain Properties of Roofing Membranes
D4073/D4073M Test Method for Tensile-Tear Strength of Bituminous Roofing Membranes
D5147/D5147M Test Methods for Sampling and Testing Modified Bituminous Sheet Material
D7349/D7349M Test Method for Determining the Capability of Roofing and Waterproofing Materials to Seal Around Fasteners
E96/E96M Test Methods for Water Vapor Transmission of Materials
3. Terminology
3.1 Definitions—For definitions of terms used in this specification, refer to Terminology D1079.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 lot—for the purpose of sampling, a lot shall consist of all material manufactured in one production run (not to exceed 24
h) using the same source of raw materials.
4. Workmanship, Finish, and Appearance
4.1 The underlayment sheet shall be supplied in roll form.
4.2 The underlayment sheet shall be substantially uniform in thickness and appearance. It shall be free of visible defects such as
holes, ragged or untrue edges, breaks, cracks, tears, protuberances, and indentations, except for those perforations or protuberances
which are intentional.
4.3 The surface of the underlayment sheet shall be designed to provide traction and slip resistance to the applicator.
NOTE 1—The intent of 4.3 is to recognize that surface slipperiness is important when working on a roof and, while no test method is specified in this
standard, several methods for assessing the relative slipperiness of surfaces are available. It is the further intent of this paragraph to ensure that, whatever
method is used, the friction coefficient or resistance to slipping of the surface of these products should be at least as great as asphalt-saturated felt shingle
underlayment tested under the same conditions of temperature and wetness as agreed between purchaser and seller.
4.4 Sheet sections shall be suitable for joining by the manufacturer’s recommended procedure. The entire lower surface of the
underlayment sheet shall be capable of being fully adhered to the roof deck.
5. Physical Requirements
5.1 The underlayment sheet shall conform to the physical requirements prescribed in Table 1.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
D1970/D1970M − 21
TABLE 1 Physical Requirements of Self-Adhering Polymer
Modified Bituminous Sheet Materials Used as Steep Roofing
Underlayment for Ice Dam Protection
Property SI Inch-Pound
Thickness, min 1.0 mm 40 mils
Maximum load, min
Longitudinal 4.4 kN/m 25 lbf/in.
Transverse 4.4 kN/m 25 lbf/in.
Elongation at break, min of modified 10 %
bitumen portion
Adhesion to plywood, min at 40 °F 0.92 kgf/30.5 cm 2.0 lbf/ft width
Adhesion to plywood, min at 75 °F 5.44 kgf/30.5 cm 12.0 lbf/ft width
Thermal stability, max 3 mm 0.1 in.
Flexibility at –29 °C [–20 °F] pass
Tear resistance
Longitudinal, min 89 N 20 lbf
Transverse, min 89 N 20 lbf
Moisture vapor permeance, max 5.7 ng/Pa.S.M. 0.1 U.S. Perms
Sealability around nail pass
Waterproof integrity of lap seam pass
5.2 The underlayment sheet shall not crack nor be so sticky as to cause tearing or other damage upon being unrolled at material
temperatures between 4.4 and 60 °C [40 and 140 °F].
6. Sampling
6.1 From each lot of underlayment sheet, select sample rolls in accordance with Test Methods D228/D228M.
6.2 The rolls so selected shall constitute the representative sample used for all subsequent observations and tests pertaining to the
lot of material being examined.
7. Test Methods
7.1 Conditioning:
7.1.1 Unless otherwise specified, condition test specimens for at least 4 h at 23 6 2 °C [73.4 6 3.6 °F] and 50 6 5 % relative
humidity prior to testing.
7.2 Thickness:
7.2.1 Measure the thickness of the roofing underlayment in accordance with Test Methods D5147/D5147M.
7.2.2 Report the number of measurements, the average, and standard deviation across the sheet.
7.3 Maximum Load and Elongation at Break:
7.3.1 This test method covers the determination of the maximum load and elongation at break of the underlayment sheets, as set
forth in Practice the Load Strain Properties section of Test Methods D2523/D2523MD5147/D5147M, except as noted below.
7.3.2 Specimens—Prepare five specimens from each sample roll in both the longitudinal and transverse directions. Specimens shall
be 25 mm [1 in.] 6 5 % wide by a minimum of 150 mm [6 in.] 6 5 % long. For materials with high elongation, it is permitted
to reduce the length of the sample may be reduced specimen to 100 mm [4 in.] 6 5 % if necessary to avoid limitations imposed
by dimensions of the test machine.
7.3.3 Procedure—Perform the following procedure.
7.3.3.1 Condition each specimen at least 2 h at 23 6 2 °C [73.4 6 3.6 °F].
D1970/D1970M − 21
7.3.3.2 Use a constant rate of elongation (CRE) tension testing machine, preferably with automatic load and strain recording
equipment and clamps that permit a uniform clamping pressure on the specimen without slipping. The initial clamp separation shall
be a minimum of 75 mm [3 in.] 6 5 % for sheets having an ultimate elongation of 75 % or less at 23.9 °C [75 °F] and 50 mm
[2 in.] 6 5 % for sheets having an ultimate elongation greater than 75 % at 23.9 °C [75 °F].
7.3.3.3 Maintain a rate of separation of 50 mm [2 in.] 6 3 % per min.
7.3.3.3 Record the percent elongation of each specimen at the visual break of the modified bitumen portion using an extensiometer,
or mark the extension at visual break of the modified bitumen portion from the chart of the stress versus time (knowing the speed
of the chart drive and the jaw separation rate).
7.3.3.4 Record the maximum load attained by each specimen.
7.3.4 Calculation—Determine the percent elongation at break of the modified bitumen portion obtained from the extensiometer
in accordance with the manufacturer’s instructions, or read directly. Calculate the percent elongation from the chart as follows:
a
%Elongation 5 3100 % (1)
b
where:
a = extension at modified bitumen break (extension at break on chart × jaw separation rate divided by chart speed), and
b = initial jaw separation.
7.3.4.1 Determine the average percent elongation at break of the modified bitumen portion in each direction.
7.3.4.2 Calculate the average maximum load in each direction.
7.3.5 Report—For each set of five specimens in each direction report the individual measurements, the average and standard
deviation for the size of specimen (initial length between jaws), maximum load in kN/m [lbf/in.], percent elongation at modified
bitumen break, and method of determining elongation.
7.4 Adhesion to Plywood:
7.4.1 This test method covers the determination of the adhesive properties of the underlayment sheets to plywood, as set forth in
Test Method D903 except as noted below.
7.4.2 Specimen Preparation—Prepare test specimens as described.
7.4.2.1 The test specimen shall consist of one piece of underlayment sheet, 75 6 2 by 200 6 2 mm [3 6 0.125 by 8 6 0.125
in.], bonded for 15 in. (75 by 125 mm) [3 by 5 in.] to one piece of 6 mm [ ⁄4 in.] minimum thick plywood, APA Grade, Exposure
1, 75 by 150 mm [3 by 6 in.]. The plywood must not be reused for testing.
7.4.2.2 Roll test specimen three times back and forth with a roller which has a mass of 11.8 kg [26 lb] 6 0.5 %, diameter of 125
mm [5 in.] 6 5 %, and width of 125 mm [5 in.] 6 5 % (2 to 3 s per cycle).
7.4.2.3 At least five specimens shall be tested for each test temperature.
7.4.2.4 It is recommended that specimens be assembled individually. Cutting specimens to size after assembly may influence the
test results.
7.4.3 Conditioning—The test shall be performed at 23 6 2 °C [73.4 6 3.6 °F] and 4 6 2 °C [39.2 6 3.6 °F]. Materials used to
construct test specimens and the roller must be conditioned at the test temperature for at least 4 h prior to assembly. Similarly, test
specimens must be conditioned at the test temperatures for at least 1 h prior to testing.
NOTE 2—Adhesion to other potential wood deck materials may be determined by this test method, but it has been observed that substrates such as
APA-approved nonveneer sheets typically give greater adhesion values than the minimum specified in this standard for plywood.
D1970/D1970M − 21
7.4.4 Apparatus—Perform the test in a constant rate of extension type tester. The rate of travel of the power-actuated grip shall
be 50 mm [2 in.]/min 6 3 %. This rate which provides a laminate separation rate of 25 mm [1 in.]/min 6 3 % shall be uniform
throughout the test.
7.4.5 Procedure—Perform the following procedure.
7.4.5.1 Conduct the test after the test specimens have been conditioned at the test temperature (in the environmental chamber) for
15 min.
7.4.5.2 Separate the free end of the underlayment sheet from the plywood for a distance of about 50 mm [2 in.] leaving about 75
mm [3 in.] of bonded length. Place the specimen in the testing machine by clamping the free end of the plywood in one grip,
turning back the free end of the sheet, and clamping it in the other grip. Maintain the specimen in the approximate plane of the
clamps during the test. Peel at least three quarters of the bonded area, even though a peel or stripping value may be indicated before
this point.
7.4.6 Calculation—Determine the peel strength on the chart as the average load line that will visually accommodate the recorded
curve. Record the load so indicated, corrected for tare.
7.4.7 Reporting—For each series of tests, report the number of measurements, the average, and the standard deviation of all the
test values in kg/30.5 cm width [lb/ft of width].
7.5 Thermal Stability:
7.5.1 This test method determines the thermal stability of the underlayment sheets as set forth in Test Method D1204, except as
noted below.
7.5.2 Specimens—Prepare test specimens as described.
7.5.2.1 The test specimen shall consist of one piece of underlayment sheet, 100 6 2 by 100 6 2 mm [4 6 0.125 by 4 6 0.125
in.], centered and bonded (as described in 7.4.2.2) to one piece of 6 mm [ ⁄4 in.] minimum thick plywood, (APA Grade, Exposure
1) 150 6 2 by 200 6 2 mm [6 6 0.125 by 8 6 0.125 in.].
7.5.2.2 At least five specimens shall be tested for each sample roll.
7.5.3 Procedure—Perform the following procedure.
7.5.3.1 Set specimens at a 45° angle in a hot air circulating oven maintained at 70 6 2 °C [158 6 4 °F] for 14 days.
7.5.3.2 At the end of the oven-exposure period, allow specimens to equilibrate to 23.9 6 1.1 °C [75 6 2 °F] and 50 6 5 % relative
humidity for at least 4 h.
7.5.3.3 From the lower edge of the sheet measure to the nearest 2.5 mm [0.1 in.] the furthest point of modified bitumen flow.
Estimate the average flow across the entire lower edge of the sample.
7.5.4 Report—Report the individual specimen values, the average, and the standard deviation.
7.6 Flexibility at –29 °C [–20 °F]:
7.6.1 Scope—This test method is a qualitative procedure performed in a laboratory that determines the low temperature flexibility
of the underlayment sheets. For the sheet material to be given a pass rating in this test, the material must demonstrate either no
visible signs of cracking after bending at the test temperature through an angle of 180 6 5° around a 25 mm [1 in.] 6 5 % diameter
mandrel in 2 6 1 s, or cracking is visible in one or more specimens that have been bent over the
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