How to Address Moisture Testing in Your Contracts
by Peter Collins - Sales Representative for Texas
As a flooring contractor, you’re not responsible for moisture in a concrete slab. However, you could be held responsible for any damage caused to the floor coating that you install, as well as any associated damages, if you did not test for the presence of moisture prior to the coating’s application in order to determine its suitability for coating or covering.
Consider the following five points:
- Improper floor preparation and moisture in concrete are the two leading causes of floor coating failures.
- It’s estimated that 90% of all commercial flooring litigation cases focus on water-related damages.
- Only 1.5% of a typical building budget is dedicated to waterproofing.
- High moisture or moisture vapor emissions contribute to mold and mildew, which affect health.
- Residual moisture in the slab from the original concrete pour can migrate toward the surface unless properly prevented.
Just because a concrete slab has been properly profiled and prepared doesn’t mean that it’s ready to be coated. Regardless of when a slab was poured, whether it’s on-grade or suspended or whether or not a moisture barrier was placed beneath it, a concrete slab may still contain an overly high amount of moisture. Testing for moisture prior to the coating or covering of a concrete slab is a standard industry practice and should always be addressed in a flooring contractor’s contract.
Testing immediately prior to a floor coating or covering installation will reveal whether or not the concrete slab is suitable for a particular flooring application. However, much like a medical test, moisture test readings taken at a particular point in time and which indicate the suitability for a floor coating or covering are not guarantees that moisture will not affect the flooring in the future. Tests are snapshots at the time they are done. All ASTMs relating to slab moisture testing stress that the tests are indicators of moisture level readings at the time of testing and are subject to change.
Following are the two most commonly accepted test methods used prior to a resinous floor coating installation and they should be a referred to in the floor coating contract:
- ASTM F1869 (Calcium Chloride Test)
- ASTM F2170 (RH Probe Test)
Moisture Testing Example Clause:
- Calcium chloride testing (following ASTM F1869 to determine the moisture vapor emission rate - MVER), in situ probe testing (following ASTM F2170 to determine the relative humidity - RH) or both are highly recommended before the installation of the floor coating.
- Moisture testing will be done prior to any floor coating installation and according to specific ASTM procedures. The results will be shared with Owner.
- Moisture testing will be done for all areas to be coated unless otherwise stated.
- Both MVER testing and RH testing give measurements at the time of testing only.
- Initial MVER testing will be done at a rate of $________ per dome and RH testing at a rate of $________ per probe.
- If testing indicates excessive levels of slab moisture content, Owner will be given moisture reduction or remediation options, including types, methods, effectiveness and costs.
- If Owner chooses to proceed with the floor coating installation without conducting one or both of the recommended moisture tests, Owner must confirm in writing their desire to proceed without testing.
- If moisture testing is declined by Owner, any and all moisture related floor coating failures will be the responsibility of the Owner. The floor coating Contractor, the Contractor’s personnel and any and all affiliates of the Contractor will not be held responsible for any moisture related floor coating failure.
For a more complete and full understanding of moisture in concrete slabs, including the dynamics and negative effects of moisture, how moisture relates to concrete floor coatings and coverings and efficient and effective moisture control and mitigation options, Arizona Polymer Flooring recommends that all floor coating professionals make the topic of moisture in concrete a continuing education priority. APF has published a helpful technical paper covering this topic that you can download here.
On a final note, ICRI (International Concrete Repair Institute) offers one of the most respected courses covering this topic. ICRI offers a two-day in-depth Concrete Slab Moisture Testing certification that outlines and makes clear the most current information regarding this subject.
Note: The above information is given for reference purposes only and is not intended as legal guidance. Arizona Polymer Flooring and its agents make no legal claims and are not responsible for any legal consequences regarding the above content. Further, Arizona Polymer Flooring is not authorized to give legal advice of any kind. All contractual and other legal considerations should be reviewed by a competent and legally licensed attorney for the U.S. state in question.