The ASTM F1869 standard provides the guidelines for conducting the calcium chloride moisture test, used in measuring the moisture vapor emission rate (MVER) for concrete subfloors.
This test can be done using the calcium chloride moisture test kit which is readily available for about $20. You can purchase the kit on Amazon, or other retail stores near you.
This test is important to ensure you understand the level of moisture in subfloors, before installation of your flooring.
Calcium Chloride Moisture Test: Step-By-Step Guide
Here is a step-by-step simplified guide on how to perform this test:
1.Gather the necessary equipment and materials:
- Calcium chloride test kit: This typically includes a plastic dish, a pre-weighed amount of calcium chloride pellets, and a sealing lid.
- Moisture vapor barrier: A non-reactive plastic sheet used to cover the test area.
- Tape: To secure the moisture vapor barrier to the concrete surface.
- Vacuum cleaner or broom: To clean the test area before beginning.
2.Prepare the test area:
- Remove any surface contaminants, debris, or loose materials from the concrete surface using a vacuum cleaner or broom.
- Ensure that the concrete surface is free from any coatings, adhesives, or curing compounds that may interfere with the test results.
3.Weigh the calcium chloride dish:
- Before opening the test kit, weigh the plastic dish containing the calcium chloride pellets to determine its initial weight.
- Record this weight as “Wi.”
4.Place the calcium chloride dish on the test area:
- Choose a representative location on the concrete surface where the test will be performed.
- Remove the lid from the calcium chloride dish and place it upside down on the concrete.
- Press down on the dish to ensure good contact with the concrete surface.
- Use tape to seal the dish tightly to the concrete, preventing any air gaps.
5.Cover the test area:
- Carefully place the moisture vapor barrier over the dish and tape it securely to the concrete surface, creating an airtight seal.
- Make sure the edges of the barrier are securely attached to the concrete to prevent any moisture ingress.
Related Posts:
6.Allow the test to run:
- Leave the calcium chloride dish undisturbed on the concrete surface for a specified duration, typically 60 to 72 hours as recommended by the manufacturer or as required by the project specifications.
- During this time, ensure that the test area is not subjected to excessive foot traffic, spills, or other disturbances that may affect the test results.
7.Collect the calcium chloride dish:
- After the specified test duration, carefully remove the moisture vapor barrier and the calcium chloride dish from the concrete surface.
- Be cautious not to spill or lose any calcium chloride pellets from the dish.
8Weigh the calcium chloride dish again:
- Immediately after removing the dish from the concrete, weigh it to determine its final weight.
- Record this weight as “Wf.”
9.Calculate the moisture vapor emission rate (MVER):
Use the following formula to calculate the MVER in pounds of moisture emitted per 1,000 square feet over a 24-hour period: MVER = (Wf – Wi) x K / A Where:
- (Wf – Wi) is the weight gain of the dish during the test, in grams.
- K is the conversion factor specified by the manufacturer to convert grams to pounds.
- A is the exposed area of the dish in square feet.
10.Interpret the test results:
- Compare the calculated MVER value with the project specifications or the requirements specified by relevant industry standards to determine if the moisture level is within acceptable limits.
NB: It is important that you carefully read and follow specific instructions provided by the manufacturer of the test kit that you have bought.
While this guide may apply to majority of the moisture test kits, slight variations between manufacturers could occur.
References
