How can you test for moisture in a concrete subfloor?

Using a moisture meter is a reliable and accurate method for testing moisture levels in a concrete subfloor. This device measures the moisture content within the material, providing quantitative data that helps determine whether the concrete is adequately dry for the installation of floor coverings. Moisture meters typically use two main methods: capacitance and resistance, allowing installers to assess moisture levels without damaging the substrate.

While other methods mentioned can provide some insights, they do not offer the same level of accuracy. A visual inspection may reveal issues such as stains or efflorescence, but it cannot accurately measure moisture content. The simple water test method involves placing a plastic sheet on the concrete and checking for condensation after a period, which can indicate moisture presence but lacks precision. Examining the surface for cracks may suggest potential moisture problems but does not directly measure moisture levels. Therefore, utilizing a moisture meter is essential for ensuring the appropriateness of the subfloor conditions prior to installation.