ASTM International

Standard Test Method for Water Retention of Rigid Thermal Insulations Following Partial Immersion
 N C1134

Annotation

This test method determines the amount of water retained (including surface water) by rigid block and board thermal insulations used in building construction applications after these materials have been partially immersed in liquid water for prescribed time intervals under isothermal conditions. This test method is intended to be used for the characterization of materials in the laboratory. It is not intended to simulate any particular environmental condition that may be encountered in building construction applications.

This test method does not address all the possible mechanisms of water intake and retention and related phenomena for rigid thermal insulations. It relates only to those conditions outlined in 1.1. Determination of moisture accumulation in thermal insulations due to complete immersion, water vapor transmission, internal condensation, freeze-thaw cycling, or a combination of these effects requires different test procedures.

Each partial immersion interval is followed by a brief free-drainage period. This test method does not address or attempt to quantify the drainage characteristics of materials. Therefore, results for materials with different internal structure and porosity, such as cellular materials and fibrous materials, may not be directly comparable. Also, test results for specimens of different thickness may not be directly comparable because of porosity effects. The surface characteristics of a material also affect drainage. Specimens with rough surfaces may retain more surface water than specimens with smooth surfaces, and surface treatment during specimen preparation may affect water intake and retention. Therefore, results for materials with different surface characteristics may not be directly comparable.

For most materials the size of the test specimens is small compared with the size of the products actually installed in the field. If the surface-to-volume ratios for the test specimens and the corresponding products are different, the test results may be misleading.