ASTM C79/C79M-00

Standard Specification for Treated Core and Nontreated Core Gypsum Sheathing Board

SCOPE
1.1 This specification covers treated core and nontreated core gypsum sheathing, which is designed to be used as a sheathing on buildings.
Note 1--Specification C1280 contains application procedures for gypsum sheathing board.
1.2 The values stated in either inch-pound or SI (metric) units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system shall be used independently of the other. Values from the two systems shall not be combined.

General Information

• Status: Historical
• Publication Date: 09-May-2001
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.01 - Specifications and Test Methods for Gypsum Products

Relations

• Replaced By: ASTM C79/C79M-01 - Standard Specification for Treated Core and Nontreated Core Gypsum Sheathing Board
• Effective Date: 10-May-2001
• Referred By: ASTM C1535-05(2023) - Standard Practice for Application of Exterior Insulation and Finish Systems Class PI
• Effective Date: 10-May-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 79/C 79M – 00
Standard Specification for
Treated Core and Nontreated Core Gypsum Sheathing
1
Board
This standard is issued under the fixed designation C 79/C 79M; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope * quired to have a water-resistant material incorporated in the
core.
1.1 This specification covers treated core and nontreated
4.2 Gypsum Sheathing, Type X (Special Fire-Resistant),
core gypsum sheathing, which is designed to be used as a
designates gypsum sheathing complying with this specification
sheathing on buildings.
5
that provides not less than 1-h fire-resistance for boards ⁄8 in.
1.2 The values stated in either inch-pound or SI (metric)
3 1
[15.9 mm] thick or ⁄4-h fire-resistance for boards ⁄2 in. [12.7
units are to be regarded separately as the standard. Within the
mm] thick, applied parallel with and on each side of load
text, the SI units are shown in brackets. The values stated in
bearing 2 by 4 wood studs spaced 16 in. [406 mm] on centers
each system shall be used independently of the other. Values
7
with 6d coated nails, 1 ⁄8in. [48 mm] long, 0.0915-in. [2.3-mm]
from the two systems shall not be combined.
1
diameter shank, ⁄4-in. [6.4-mm] diameter heads, spaced 7 in.
2. Referenced Documents
[178 mm] on center with gypsum sheathing joints staggered 16
in. [406 mm] on each side of the partition and tested in
2.1 ASTM Standards:
accordance with Test Methods E 119.
C 11 Terminology Relating to Gypsum and Related Build-
2
ing Materials and Systems
NOTE 1—Consult producers for independent test data on assembly
C 473 Test Methods for Physical Testing of Gypsum Board
details and fire resistance classifications for other types of construction.
2
See official fire test reports for assembly particulars, materials, and
Products and Gypsum Lath
classifications.
C 645 Specification for Nonstructural Steel Framing Mem-
2
bers
5. Physical Properties
C 1264/C1264M Specification for Sampling, Inspection,
5.1 Specimens shall be taken from the samples obtained in
Rejection, Certification, Packaging, Marking, Shipping,
2
accordance with 8.1.
Handling, and Storage of Gypsum Board
5.1.1 Specimens shall be tested in accordance with Test
E 119 Test Methods for Fire Tests of Building Construction
3
Methods C 473.
and Materials
5.1.2 Flexural Strength—The specimens shall be tested face
3. Terminology up and face down. The average breaking load shall be not less
than the following:
3.1 Definitions used in this specification shall be in accor-
Method A Method A Method B Method B
dance with Terminology C 11.
Bearing Edges Bearing Edges Bearing Edges Bearing Edges
Perp to Panel Par to Panel Perp to Panel Par to Panel
4. Materials and Manufacture
Thickness Length Length Length Length
in. [mm] lbf [N] lbf [N] lbf [N] lbf [N]
4.1 Gypsum sheathing shall consist of a noncombustible
core, essentially gypsum, surfaced on both the face and the
3
⁄8 [9.5] 80 [356] 30 [133] 77 [343] 26 [116]
back with water-repellent paper bonded to the core. 4
⁄10 [10.2] 88 [391] 32 [142] 85 [378] 28 [125]
1
⁄2 [12.7] 110 [489] 40 [178] 107 [476] 36 [160]
4.1.1 Treated core gypsum sheathing shall have a water-
5
⁄8 [15.9] 150 [667] 50 [222] 147 [654] 46 [205]
resistant material incorporated into the core.
4.1.2 Nontreated core gypsum sheathing shall not be re- 5.1.3 Humidified Deflection—The specimens shall have an
average deflection of not more than the following:
Thickness Deflection
1
This specification is under the jurisdiction of ASTM Committee C11 on
in. [mm] eighths of an inch [mm]
Gypsum and Related Building Materials and Systems and is the direct responsibility
of Subcommittee C11.01 on Specifications and Test Methods for Gypsum Products. 3
⁄8 [9.5] 15 [48]
Current edition approved July 10, 2000. Published September 2000. Originally 4
⁄10 [10.2] 12 [38]
1
published as C 79 – 30 T. Last previous edition C 79/C 79M – 97.
⁄2 [12.7] 10 [32]
2
5
Annual Book of ASTM Standards, Vol 04.01.
⁄8 [15.9] 5 [16]
3
Annual Book of ASTM Standards, Vol 04.07.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
C 79/C 79M
1
5.1.4 Core, End, and Edge Hardness—The specimens shall permissible local variations of 6 ⁄16 in. [61.6 mm] from the
have an average hardness of not less than 15 lbf [67 N] when nominal thickness.
tested by Method A and 11 lbf [49 N] when tested by Method 6.2.2 Width—The
...