ASTM D4897-98
(Specification)Standard Specification for Asphalt-Coated Glass-Fiber Venting Base Sheet Used in Roofing
Standard Specification for Asphalt-Coated Glass-Fiber Venting Base Sheet Used in Roofing
SCOPE
1.1 This specification covers asphalt impregnated and coated glass fiber base sheet with fine mineral surfacing on the top side and coarse mineral granules on the bottom side for use as the first ply of a roofing membrane. These base sheets provide for the lateral release of pressure in roofing systems because they are not solidly attached and the coarse granular surface provides an open, porous channel in the horizontal plane beneath the membrane. The base sheets may be with or without perforations or embossings.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
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NOTICE: This standard has either been superseded and replaced by a new version or
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Designation: D 4897 – 98
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Asphalt-Coated Glass-Fiber Venting Base Sheet Used in
1
Roofing
This standard is issued under the fixed designation D 4897; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope distributed glass fibers, with or without the addition of rein-
forcing strands, or glass yarns, which are bonded with a
1.1 This specification covers asphalt impregnated and
water-resistant resinous binder.
coated glass fiber base sheet with mineral surfacing on the top
5.2 In the process of manufacture the glass mat is impreg-
side and coarse mineral granules on the bottom side for use as
nated and coated on both sides with a hot asphaltic coating with
the first ply of a roofing membrane. These base sheets provide
or without a mineral stabilizer and surfaced on the bottom side
for the lateral release of pressure in roofing systems because
with coarse mineral granules embedded in an asphaltic coating.
they are not solidly attached and the coarse granular surface
The top side shall be surfaced with fine mineral surfacing.
provides an open, porous channel in the horizontal plane
5.3 The product shall be permitted to be embossed or
beneath the membrane. The base sheets shall be permitted to be
unembossed on the bottom side. The product shall be permitted
with or without perforations or embossings.
to contain holes designated for attachment with mopping
1.2 The values stated in inch-pound units are to be regarded
asphalt.
as the standard. The values given in parentheses are for
information only.
6. Physical Requirements, Dimensions, and Masses
2. Referenced Documents 6.1 The material at the point of manufacture shall conform
to the physical requirements in Table 1 and the dimensions and
2.1 ASTM Standards:
masses in Table 2.
D 146 Test Methods for Sampling and Testing Bitumen-
6.2 The finished product shall not crack nor be so sticky as
Saturated Felts and Woven Fabrics Used in Roofing and
2
to cause tearing or other damage upon being unrolled at
Waterproofing
temperatures between 50 and 140°F (10 and 60°C).
D 228 Test Methods for Asphalt Roll Roofing, Cap Sheets,
2
6.3 Pliability at 77 6 2°F (25 6 1°C)—At least eight out
and Shingles
of ten strips shall not crack when tested in accordance with Test
D 1079 Terminology Relating to Roofing, Waterproofing,
2
Methods D 228 except, for convenience, that the strips shall be
and Bituminous Materials
conditioned in ambient conditions at 77 6 2°F (25 6 1°C) for
3
3. Terminology at least 30 min prior to testing over a ⁄4-in. (19-mm) radius.
6.4 Loss and Behavior on Heating—There shall be no
3.1 Definitions—For definitions of terms used in this speci-
flowing, sagging, or blistering of the asphalt coating when
fication, refer to Terminology D 1079.
tested in accordance with Test Methods D 228.
4. Classification
7. Workmanship, Finish, and Appearance
4.1 Type I—Standard Asphalt-Coated Glass-Fiber Venting
7.1 The glass mat shall be impregnated and shall show no
Base Sheet
white spots at any point.
4.2 Type II—Heavy-Duty Asphalt-Coated Glass-Fiber Vent-
7.2 The coating shall be applied to each side to the edges of
ing Base Sheet
the sheet. The coating must be smooth.
5. Materials and Manufacture
7.3 The top side shall be surfaced with mineral surfacing to
prevent the roofing from sticking in the package.
5.1 The mat shall be a thin porous sheet of uniformly
7.4 The bottom side shall be surfaced with coarse mineral
matter, at least 90 % retained on a 212-μm (No. 70) sieve,
1
embedded in the asphalt coating.
This specification is under the jurisdicton of ASTM Committee D-8 on
Roofing, Waterproofing, and Bituminous Materials and is the direct responsibility of
7.5 The finished material shall be free of visible external
Subcommittee D08.04 on Felts and Fabrics for Bituminous Roofing and Water-
defects, such as holes, ragged or untrue edges, breaks, cracks,
proofing.
tears, protuberances, and indentations, except for intentionally
Current edition approved Jan. 10, 1998. Published September 1998. Originally
published as D 4897 – 89. Last previous edition D 4897 – 97a.
provided holes or embossing.
2
Annual Book of ASTM Standards, Vol 04.04.
1
---------------------- Page: 1 ----------------------
D 4897
TABLE 1 Physical Requirements
requirements as stated in this specification constitutes grounds
Type I Type II
for rejection.
Breaking strength, min, at 77 6 2°F (25 6 1°C) 22 (3.9) 44 (7.7)
10.2 Rejection Redress
...
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