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ASTM C209
Standard Test Methods for Cellulosic Fiber Insulating Board
Overview
ASTM C209 is a test method standard covering procedures for evaluating the physical, mechanical, and thermal properties of cellulosic fiber insulating board. These test methods describe the performance of insulating board used in building construction for applications such as roofing substrate, structural wall sheathing, and sound-deadening boards.
Key Test Methods
- Transverse, tensile, and compressive strength testing
- Water absorption and linear expansion evaluation
- Thermal resistance (R-value) measurement
- Flame spread index per ASTM E84
Water Resistance Testing
The water absorption test is critically important for exterior applications like wall sheathing. The standard's procedure involves submersion in liquid water, providing a more rigorous evaluation of moisture resistance compared to water vapor tests. Low water absorption is essential, as moisture can degrade thermal performance and lead to material deterioration and mold growth.
Building Applications
ASTM C209 provides the quality assurance framework behind cellulosic fiberboard performance data. The test results are used to verify compliance with ASTM C208 material specifications, which are referenced in building codes for insulation, fire safety, and structural applications like wall sheathing. This data allows specifiers to make informed decisions about material suitability for environments where incidental water exposure is possible.