ASTM D6878/D6878M-21

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Designation: D6878/D6878M − 19 D6878/D6878M − 21
Standard Specification for
Thermoplastic Polyolefin Based Polyolefin-Based Sheet
Roofing
This standard is issued under the fixed designation D6878/D6878M; 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 flexible sheet made from thermoplastic polyolefin (TPO) as the principal polymer, intended for use
in single-ply roofing membranes exposed to the weather. The sheet shall contain reinforcing fabrics or scrims.
1.2 The tests and property limits used to characterize the sheet are values intended to ensure minimum quality for the intended
purpose. In-place roof system design criteria, such as fire resistance, field seaming strength, material compatibility, and uplift
resistance, among others, are factors which should be considered but are beyond the scope of this specification.
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-conformancenonconformance with the standard.
1.4 This standard may involve hazardous materials, operations, and equipment. 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 requirements 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.
2. Referenced Documents
2.1 ASTM Standards:
D471 Test Method for Rubber Property—Effect of Liquids
D573 Test Method for Rubber—Deterioration in an Air Oven
D751 Test Methods for Coated Fabrics
D1149 Test Methods for Rubber Deterioration—Cracking in an Ozone Controlled Environment
D1204 Test Method for Linear Dimensional Changes of Nonrigid Thermoplastic Sheeting or Film at Elevated Temperature
D2137 Test Methods for Rubber Property—Brittleness Point of Flexible Polymers and Coated Fabrics
D5538 Practice for Thermoplastic Elastomers—Terminology and Abbreviations
D7635/D7635M Test Method for Measurement of Thickness of Coatings Over Fabric Reinforcement
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
This specification is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.18 on
Nonbituminous Organic Roof Coverings.
Current edition approved July 15, 2019Nov. 1, 2021. Published August 2019November 2021. Originally approved in 2003. Last previous edition approved in 20172019
as D6878/D6878M – 17.D6878/D6878M – 19. DOI: 10.1520/D6878_D6878M-19.10.1520/D6878_D6878M-21.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6878/D6878M − 21
G155 Practice for Operating Xenon Arc Lamp Apparatus for Exposure of Materials
3. Materials and Manufacture
3.1 The sheet shall be formulated from ethylene and higher alpha-olefin polymers, copolymers, and mixtures thereof, in amounts
greater than 50 %,50 % by weight of the total polymer content, suitably compounded to satisfy the physical requirements in the
specification (see Practice D5538).
3.2 The sheet shall be capable of being heat welded, fused, or adhesively bonded to itself for making watertight field splices and
repairs, and the supplier or fabricator shall recommend suitable methods and materials.
3.3 Sheet shall be reinforced with fabric or scrim.
4. Physical Properties and Tolerances
4.1 Each sheet specimen shall meet or exceed the physical requirements prescribed in Table 1.
4.2 The tolerance for time conditions (aging, weathering, and so forth) is 615 min or 61 % of the period, whichever is greater,
unless otherwise specified.
4.3 The tolerance for temperature conditions (aging, weathering, and so forth) is 62°C [64°F]62 °C [64 °F] of the specified
temperature, unless otherwise specified.
5. Dimensions and Permissible Variations
5.1 The width and length of the sheet shall be agreed upon between the purchaser and the supplier.
5.1.1 The width and length tolerance shall be +3 %, −0 %.
5.1.2 The thickness tolerance shall be +15 %, –10 % of thickness agreed upon by the purchaser and supplier, but in no case shall
it be less than the minimum in Table 1.
5.1.3 The thickness of coating over scrim (reinforcing fabric) of the weathering side shall be at least 30 % of the overall thickness
as agreed upon by the purchaser and supplier, but in no case shall it be less than the minimum in Table 1. The table below can
be used as a reference for commonly used thicknesses.
TABLE 1 Physical Requirements for TPO Sheet
Thickness, min, mm [in.]
Sheet-overall 1.0 [0.039]
Coating over fabric or scrim, weathering side only 0.38 [0.015]
Breaking strength, min, N [lbf] 976 [220]
Elongation at reinforcement break, min, % 15
Tearing strength, min, N [lbf] 245 [55]
Brittleness point, max, °C [°F] -40 [-40]
Brittleness point, max, °C [°F] –40 [–40]
Ozone resistance, no cracks Pass
Properties after heat aging:
Weight change (mass), max % ±1.5
Inspect at 7× magnification for cracks when bent Pass
over a 3 in. diameter mandrel
Linear dimensional change, max, % ±1
A
Water absorption, max, mass % ±3.0
Factory seam strength, min, N [lbf] 290 [66]
Weather resistance:
Visual inspection Pass
A
Test performed on top coating material only. (Use Test Method D471, Procedure
for Change in Mass.)
D6878/D6878M − 21
Overall Thickness, mm [in.] Thickness of Coating Over Scrim, min, mm [in.]
1.1 [0.045] 0.38 [0.015]
1.5 [0.060] 0.48 [0.018]
2.0 [0.080] 0.60 [0.024]
6. Workmanship, Finish, and Appearance
6.1 The sheet, including factory seams, if present, shall be watertight and free of pinholes, particles of foreign matter, protruding
fibers or reinforcement, undispersed raw material, nicks and cuts, voids, thin areas, delaminations, or other manufacturing defects
that might adversely affect serviceability.
6.2 Edges of the sheets shall be capable of being seamed to one another without fishmouthing.
7. Test Methods
7.1 Dimensions—Test Methods D751, after permitting the sheet to relax at 23°C [73°F]23 °C [73 °F] for 1 h.
7.2 Thickness, Sheet Overall—Refer to Test Methods D751.
7.3 Thickness of Coating Over Scrim (Reinforcing Fabric)—Test Method D7635/D7635M. Follow preparation procedures as
specified in Test Method D7635/D7635M. The thickness measurements shall be conducted as described in the test method on the
coating on the side intended to be exposed to the weather.
7.4 Breaking Strength—Test Methods D751, Grab Method.
7.5 Elongation at Break—Test Methods D751, Grab Method.
7.6 Tearing Strength—Test Methods D751, 2 in./min jaw speed [8 by 8 in. sample size].
7.7 Brittleness Point—Te
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