ASTM – The American Society for Testing and Methods – is a non-profit organization that has been in existence for more than 100 years. ASTM is a voluntary organization that anyone may join, and is not a regulatory agency. The value of ASTM has long been recognized, and it has become an extremely valuable source of architectural specifications and reference points for manufacturers, laboratories, consultants, and last but not least, litigators.
The resilient industry in particular is interested in and is part of the ASTM, specifically F06 Resilient Floor Coverings. There are many subcommittees within F06, including F-06.60 Slip Resistance, and F-06-40.03 Relative Humidity and Concrete, and others dealing with subjects like dimensions, resilient construction, and quality.
I would have you look at a few ASTMs that deal primarily with the prepping or testing of concrete slabs. Document D-4263-83, titled Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method, is intended to indicate the presence of capillary moisture in concrete. This method was primarily designed to test concrete prior to the installation of coatings, but has since found use in the resilient industry.
The document is also referenced in E1907-97 Standard Practices for Determining Moisture-Related acceptability of Concrete Floors to Receive Moisture-Sensitive Finishes. E1907-97 is under the jurisdiction of ASTM E-6 On Performance of Building Construction. There are eight procedures in E1907-97, commonly referred to as “tests,” used in the construction industry to determine if unacceptable moisture is present in or is being emitted from concrete slabs.
It is important to note at this time that these procedures, although called tests, are to be evaluated in conjunction with the judgment and experience of the tester.
The eight procedures listed in E1907-97 are:
- Polyethylene Sheet Test (see D4263-83 (93)) Mat Test Electrical Resistance Test (2 electorates probes) Electrical Impedance Test Qualitative Calcium Chloride Test Quantitative Calcium Chloride Test Primer or Adhesive Strip Test Hygrometer
In all cases where testing is performed, the test area should be at the same internal conditions as expected during normal service. A study is in progress to develop a standard test method for determining the relative humidity of a slab, as it has been well established that vapor transmission rates are closely related to the difference in air pressures in the test area.
Also, in the appendix of E1907-97 you will find X1, the Effects of Moisture, which deals with the adverse impacts and acceptable levels of moisture. X1.4 discusses possible sources of water intrusion, and X1.5 addresses drying time and vapor (air) pressure determination. In X18.104.22.168, the Resilient Floor Covering Institute warns that a concrete floor must be allowed to cure and dry a minimum of six weeks. The Portland Cement Association states that drying times vary, and that in most cases several months are required after moist curing.
ASTM F710-98, Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring, is another important document that should be examined. F710-98 is primarily concerned with floor preparation, and discusses treating surface cracks, depressions, control joints, and other non-moving joints or irregularities. It also covers expansion joints, isolation joints, and other moving joints.
F710-98 also includes moisture testing and refers to the calcium chloride test in ASTM F1869-98. It details the requirement for testing alkalinity, where readings of nine or greater have been known to affect both resilient flooring and adhesives. (Note: The presence of alkali indicates vapor/moisture through the slab. There may be residual alkaline salts on new concrete slabs that are easily removed with water.)
The latest document, ASTM F1869-98, is the Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor using Anhydrous Calcium Chloride.
There are two calcium chloride test methods, qualitative and quantitative. F1869-98 is a quantitative method, meaning that instead of being limited to visual results, the test actually measures the pounds of water being emitted over a specific time period.
The test determines the rate of moisture vapor emitted from below-grade, on-grade, and above-grade (suspended) concrete floors.
F1869-98 is a formalized rendition of the decades-old Rubber Manufacturer’s Association test kit. The changes adopted in F1869-98 tend to make the RMA test procedures obsolete. F1869-98 does not set an acceptable value in pounds. Rather, it refers the user to the floor manufacturer’s limitations.
Anyone interested in obtaining ASTM documents may write to: ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428.