The American Society for Testing and Materials (ASTM) has created a list of standards for how flooring contractors must perform calcium chloride tests. This standard is designed to ensure that the most accurate results are gathered and that flooring contractors know what to do to minimize the moisture from concrete flooring.
When floor covers over a concrete sub floor fail, a major cause of that is moisture that passes through the concrete. Without anticipating the type of moisture that they have to deal with, flooring installers may mistakenly make preparations for a floor covering that is doomed to fail. The ASTM 1869 kit is the most current as of 2017 and it helps flooring experts test for concrete dryness.
The ASTM 1869 procedures are as follows:
- Remove a 20”x 20” area of old floor (such as the floor covering, coating, bond-breaker, curing compound, etc.)
- Prep or condition the area at least 48 hours before conducting the test.
- Let out gas for 24 hours.
- Acclimate for 24 hours.
- Weight CaCl crystals before installing while on site.
- Install three test kits for the first 1000 square feet, and one test for every 1000 square feet after that.
- Calculate the moisture emission rate in terms of lbs/1000 sq. ft./24 hours.
A variation in the ASTM E-1907-97 uses the same kits but they need to be placed every 500 sq. ft. and out-gas and acclimate for 48 hours. In this scenario, there is no specified floor area to be removed before that test.
When flooring installers and contractors learn what it takes to get the right readings on concrete floors by performing calcium chloride tests, they are well on their way to doing a fine job of installing floor coverings and pleasing the client.