ASTM C1280-99

Standard Specification for Application of Gypsum Sheathing

SCOPE
1.1 This specification covers the minimum requirements for, and methods of application of, gypsum sheathing for use as a substrate for exterior wall cladding.
1.2 Details of construction for a specific assembly to achieve the required fire resistance shall be obtained from reports of fire-resistance tests, engineering evaluations, or listings from recognized fire testing laboratories.
1.2.1 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the fire-rated construction.
1.3 Where sound control is required for a gypsum sheathing assembly, the details of construction shall be in accordance with the acoustical test report of an assembly that has met the required acoustical value(s).
1.3.1 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the sound-rated construction.
1.4 Where resistance to racking loads or shear is required for a gypsum sheathing assembly, the details of construction shall be in accordance with the racking or shear test report of an assembly that has met the required racking or shear value(s).
1.4.1 This specification shall govern where it is more stringent (size or thickness of framing and size and spacing of fasteners) than the racking or shear-tested construction.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units may be approximate.
1.6 The text of this standard references footnotes which provide explanatory material. These footnotes shall not be considered as requirements of the standard.  
1.7 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Dec-1999
• ICS: 91.060.10 - Walls. Partitions. Facades
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.03 - Specifications for the Application of Gypsum and Other Products in Assemblies

Relations

• Replaced By: ASTM C1280-04 - Standard Specification for Application of Gypsum Sheathing
• Effective Date: 01-May-2004
• Referred By: ASTM C1063-23 - Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster
• Effective Date: 10-Dec-1999
• Referred By: ASTM C1535-05(2023) - Standard Practice for Application of Exterior Insulation and Finish Systems Class PI
• Effective Date: 10-Dec-1999
• Referred By: ASTM C1397-13(2019) - Standard Practice for Application of Class PB Exterior Insulation and Finish Systems (EIFS) and EIFS with Drainage
• Effective Date: 10-Dec-1999
• Referred By: ASTM C1396/C1396M-17 - Standard Specification for Gypsum Board
• Effective Date: 10-Dec-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C 1280 – 99
Standard Specification for
Application of Gypsum Sheathing
This standard is issued under the fixed designation C 1280; 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 2. Referenced Documents
1.1 This specification covers the minimum requirements for 2.1 ASTM Standards:
and methods of application of gypsum sheathing for use as a C 11 Terminology Relating to Gypsum and Related Build-
substrate for exterior wall cladding. ing Materials and Systems
1.2 Details of construction for a specific assembly to C 79/C 79M Specification for Treated Core and Nontreated
achieve the required fire resistance shall be obtained from Core Gypsum Sheathing Board
reports of fire-resistance tests, engineering evaluations, or C 954 Specification for Steel Drill Screws for the Applica-
listings from recognized fire testing laboratories. tion of Gypsum Panel Products or Metal Plaster Bases to
1.2.1 This specification shall govern where it is more Steel Studs from 0.033 in. (0.84 mm) to 0.112 in. (2.84
stringent (size or thickness of framing and size and spacing of mm) in Thickness
fasteners) than the fire-rated construction. C 955 Specification for Load-Bearing (Transverse and
1.3 Where sound control is required for a gypsum sheathing Axial) Steel Studs, Runners (Tracks), and Bracing or
assembly, the details of construction shall be in accordance Bridging for Screw Application of Gypsum Panel Products
with the acoustical test report of an assembly that has met the and Metal Plaster Bases
required acoustical value(s). C 1002 Specification for Steel Drill Screws for the Appli-
1.3.1 This specification shall govern where it is more cation of Gypsum Panel Products or Metal Plaster Bases
stringent (size or thickness of framing and size and spacing of C 1007 Specification for the Installation of Load Bearing
fasteners) than the sound-rated construction. (Transverse and Axial) Steel Studs and Related Accesso-
1.4 Where resistance to racking loads or shear is required ries
for a gypsum sheathing assembly, the details of construction C 1063 Specification for Installation of Lathing and Furring
shall be in accordance with the racking or shear test report of to Receive Interior and Exterior Portland Cement-Based
an assembly that has met the required racking or shear value(s). Plaster
1.4.1 This specification shall govern where it is more 2.2 U.S. Department of Commerce Publication:
stringent (size or thickness of framing and size and spacing of PS20 American Softwood Lumber Standard
fasteners) than the racking or shear-tested construction.
3. Terminology
1.5 The values stated in inch-pound units are to be regarded
as the standard. The SI (metric) values given in parentheses are 3.1 Definitions: Definitions shall be in accordance with
Terminology C 11.
approximate and are provided for information purposes only.
1.6 The text of this standard references footnotes which 3.2 Definitions of Terms Specific to This Standard:
3.2.1 exterior cladding, n—a permanent material or system
provide explanatory material. These footnotes shall not be
considered as requirements of the standard. that impedes the transmission of environmental elements to the
sheathing.
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.2.2 fastener, n—nails, staples, or screws used for applica-
tion of the sheathing.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.2.3 framing member, n—studs, headers, bracing, and
blocking that serve to receive the sheathing.
bility of regulatory limitations prior to use.
3.2.4 horizontal application, n—a synonym for perpendicu-
lar application.
This specification is under the jurisdiction of ASTM Committee C-11 on
Gypsum and Related Building Materials and Systems and is the direct responsibility
of Subcommittee C11.03 on Specifications for Application of Gypsum and Other
Products in Assemblies. Annual Book of ASTM Standards, Vol 04.01.
Current edition approved Dec. 10, 1999. Published February 2000. Originally Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
published as C 1280 – 94. Last previous edition C 1280 - 98. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 1280
TABLE 1 Minimum Fastener Lengths
3.2.5 parallel application, n—gypsum sheathing applied
with the edges parallel to the framing members; a synonym for Framing Fastener Sheathing Thickness, in. Minimum Fastener Length, in.
Type Type (mm) (mm)
vertical application.
1 1
Wood nails ⁄2 (12.7) 1 ⁄2 (38)
3.2.6 perpendicular application, n—gypsum sheathing ap-
5 3
⁄8 (15.9) 1 ⁄4 (45)
plied with the edges at right angles to the framing members; a
1 1
screws ⁄2 (12.7) 1 ⁄4 (32)
5 1
synonym for horizontal application.
⁄8 (15.9) 1 ⁄4 (32)
1 1
staples ⁄2 (12.7) 1 ⁄2 (38)
3.2.7 require, v—to mandate by a force outside this speci-
5 3
⁄8 (15.9) 1 ⁄4 (45)
fication, such as a building code, project specification, contract,
Steel screws ⁄2 (12.7) 1 (25)
5 1
or purchase order.
⁄8 (15.9) 1 ⁄4 (32)
3.2.8 specified, adj—pertaining to a mandatory requirement
of this specification or a referenced requirement.
3.2.9 specify, v—to mandate by an obligation of this stan-
5.2.3 Staples—Staples shall be of galvanized steel, not less
dard or a referenced document.
than 16-gage, ⁄16-in. (11.1-mm) wide crown outside measure-
3.2.10 vertical application, n—synonym for parallel appli-
ment. Legs shall have divergent points.
cation.
5.3 Framing Members:
3.2.11 weather resistive barrier, n—a temporarily exposed
5.3.1 Wood Framing—Wood framing members shall con-
protective membrane that is intended to impede the penetration
form to PS20.
of environmental elements until the installation of a permanent
5.3.2 Steel Framing—Load-bearing steel framing shall
exterior cladding.
meet the requirements of Specification C 955.
4. Exposure After Installation
6. Substrate, Surface Preparation
4.1 Core-Treated Gypsum Sheathing Board—Core-treated
6.1 The maximum spacing for framing members for gyp-
gypsum sheathing board is a substrate that shall be covered by
sum sheathing shall be not more than 24 in. (610 mm) on
an exterior cladding or other weather-resistive barrier and is
center on walls.
not intended for long-term exposure. It shall not be exposed to
6.1.1 Wood framing shall be straight and true, attached
the elements for more than 30 days after it has been installed.
securely following accepted engineering practices and as
The core-treated gypsum sheathing shall be covered with a
required for the intended design. The surfaces to which
weather-resistive barrier within 30 days if the exposure time
abutting edges or ends of gypsum sheathing are to be attached
will be more than 30 days.
shall be not less than 1 ⁄2-in. (38-mm) wide. The bearing
NOTE 1—Some building codes require an additional weather-resistive surface shall be not less than ⁄4 in. (1
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