ASTM C318/C318M-13 (R2018) PDF Download

ASTM C318/C318M-13 (R2018) is a standard specification that outlines the minimum requirements for gypsum formboard. This formboard is specifically designed to be used as a permanent form for poured-in-place reinforced gypsum concrete roof decks. The formboard consists of a noncombustible core, which is predominantly made of gypsum, either organic or mineral, and can be either synthetic or natural in nature.

To ensure that the formboard meets the specified standards, various tests are conducted. These tests include flexural strength to measure the board's resistance to bending, humidified deflection to evaluate its response to moisture, core, end, and edge hardness to assess its durability, and resistance to fungi to ensure it can withstand fungal growth. Additionally, the formboard is examined for its thickness, width, length, end squareness, and edges and ends to guarantee its dimensional accuracy.

The standard emphasizes that the surfaces of the gypsum formboard must be true and free from imperfections that could render it unsuitable for use, whether with or without decoration. The presence of explanatory notes in the standard's text is highlighted, clarifying that these notes are not considered mandatory requirements for compliance with the standard.