Moisture permeating from concrete floor slabs affects the performance of flooring systems such as resilient, wood, textile floor coverings and resinous coatings. Manufacturers of such systems generally require humidity/moisture testing be performed before installation over concrete floor slabs. The measurement of relative humidity (RH) directly above the porous surfaces of a floor slab is one such method.

Excessive moisture in or emitting from floor slabs after installation can cause floor covering system failures such as delamination, bonding failure, deterioration of finish flooring and coatings, and microbial growth.

The surface RH Hood (relative humidity) test method is intended to quantify the relative humidity condition that exists at the surface of a floor slab to which a floor covering or coating shall be applied. Results indicate moisture content conditions at the time of the test, as moisture movement within the slab is dynamic. See A1.4 for reference to some methods of determining moisture/humidity levels in a concrete slab.

1.1 This test method covers the quantitative determination of percent relative humidity above the surface of concrete floor slabs for field or laboratory tests.

1.2 The values given in parentheses are for information only.

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. Some specific warnings are given in Section .