Rationale

ASTM F1869 Suggested Revisions The following changes to the ASTM F1869 test method are being suggested to improve the value of the data the test procedure provides. Moisture Vapor Emission Rate (MVER) Testing has fallen out of favor over the past decade due to the inability of the current procedure to predict or establish the actual MVER rate that the floor covering is, or will be exposed to once the slab is covered. Concrete floor slabs on a vapor retarder, or metal decking dry from the top down which means that the MVER test procedure is being performed on the driest portion of the slab. Once the surface of a concrete floor slab is covered by a non-breathable floor covering or coating, moisture that is present deeper within the concrete will rise and increase the presence of moisture in the drier surface region of the slab. This migration of moisture to the surface region of the slab can result in a higher MVER being measured than when a new slab is tested in bare state, or when an area of existing flooring is removed, the surface ground, and allowed 24 hours to vent before the test kit is installed. Currently the F1869 Test Method calls for the size of the prepared test area to be 20" x 20". However, tests conducted jointly by Concrete Constructives and Simpson, Gumpertz, & Heger found no significant difference in the MVER rate between 12" x12", 16" x 16" and 20"x 20" prepared areas on a new, bare concrete floor slab. For practicality, requiring that a 16" x 16” area be the size of the vacuum ground surface allows for a single 18" x 18" flooring product to be removed to perform the test.