Moisture test for concrete

 

The presence of moisture in concrete may impair the product’s adherence. It is therefore necessary to test the moisture content in concrete before applying any product.

The presence of moisture in concrete may impair the product’s adherence. It is therefore necessary to test the moisture content in concrete before applying any product.

Checklist

  • Masking tape and plastic films
  • Electronic instrument (optional)

Testing moisture content in concrete:

  1. Let concrete dry for 72 hours after cleaning before running a moisture test.
  2. Before testing moisture content, make sure that the concrete temperature is higher than 15 °C (60 °F). Low temperatures slow down the humidity migration and tamper results.
  3. Test the surface moisture content on 4 or 5 areas. You may use an electronic instrument or fasten plastic films (polyethylene) with a masking tape on surface areas to be tested. Leave the plastic films on for 24 hours if the temperature exceeds 20 °C, and 3 days if the temperature ranges between 5 °C and 20 °C. The test cannot be run if the temperature is lower than 5 °C. After the required time, check for any sign of moisture (droplets under the plastic films).
  4. If there are no indications of moisture, apply the product of your choice. If moisture is present, build a raised floor with a moisture barrier.