ASTM C842-05(R2021) pdf free download

ASTM C842-05(R2021) pdf free download.Standard Specification for Application of Interior Gypsum Plaster
1. Scope
1.1 This specification covers the minimum requirements for full-thickness (in accordance with Table 1) interior gypsum plastering on gypsum, metal, masonry, or monolithic concrete bases designed or prepared to receive gypsum plaster. 1.1.1 Gypsum plaster applied to the interior side of exterior walls ofmasonry or concrete shall be isolated from the exterior wall. 1.2 Gypsum plasters shall not be used in exterior locations or interior “wet” areas. N OTE 1—To secure desirable results, this specification should be coordinated with the provisions of Specification C841. General informa- tion concerning full thickness gypsum plastering is contained in AnnexA2 – Annex A4. 1.3 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. 1.4 Details of construction to achieve required sound con- trol shall be obtained from reports of tests conducted at recognized sound testing laboratories in accordance with the applicable sound tests of Test Methods E90, C423, or E492. 1.5 The values stated in inch-pound units are to be regarded as the standard. The SI (metric) values given in parentheses are approximate and are provided for information purposes only. 1.6 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 1.7 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
5. Protection of Materials
5.1 Plasters and other cementitious materials shall be kept dry until used; they shall be stored off the ground, under cover, and away from walls with condensation and other damp surfaces. Metal products shall be protected, while stored, against rusting.
6. Environmental Conditions
6.1 Temperatures—Where the ambient outdoor temperature at the building site is less than 55 °F (13 °C), a temperature of not less than 55 °F (13 °C) and not more than 80 °F (27 °C) shall be maintained continuously inside the building for a period of not less than one week prior to the application of plaster (Note 2). Temporary heat shall be evenly distributed, using deflective or protective screens to prevent concentrated or uneven heat or cold on the plaster, and maintained until the permanent HVAC system is activated. N OTE 2—The requirement should minimize the possibility of plaster cracking due to structural movements caused by thermal changes from outdoor temperature extremes during construction. 6.2 Ventilation—Sufficient ventilation shall be provided to remove excess water given offthrough the drying process. (See Appendix X2 for provisions for ventilating underside of roofs and glazed buildings with and without operable windows.)
7. Materials
7.1 Gypsum Plasters—The following plasters shall conform to Specification C28/C28M: 7.1.1 Ready mixed. 7.1.2 Neat. 7.1.3 Wood-fibered. 7.1.4 Gauging for finish coat. 7.2 Gypsum Casting and Molding Plasters—Specification C5, C59/C59M. 7.3 Gypsum Keene’s Cement—Specification C61/C61M. 7.4 Lime: 7.4.1 Finishing Hydrated Lime—Specification C206, Type S. 7.4.2 Quicklime for Structural Purposes—Specification C5. 7.4.3 Lime Putty for Structural Purposes—Specification C1489. 7.5 Lime Putty—Lime putty exceeding 8 weight % of unhydrated magnesium oxide shall not be used for finish coat plaster. 7.6 Aggregates: 7.6.1 Aggregates for Base Coat Plaster—Specification C35.