SPC Flooring Moisture Test Before Installation Guide 2025
Moisture in concrete subfloors is a hidden problem that can cause serious damage to SPC flooring. Testing before installation is essential. This guide explains how to test and what to do with the results.
Why Moisture Testing Matters
Concrete subfloors release moisture vapor over time. This is a natural process as concrete cures. If SPC flooring is installed over concrete with high moisture the moisture can get trapped under the floor. This can cause mold growth on the subfloor and white deposits on the locking edges of the planks. The flooring itself may not be damaged but the subfloor can develop problems that require removing the floor.
When to Test
Test concrete moisture before every basement installation. Test when installing over new concrete less than 6 months old. Test if there is any history of moisture problems in the building. Test if the concrete is in contact with the ground.
How to Test
Use a concrete moisture meter for a quick reading. Place the meter on the concrete surface and record the reading. A reading below 95 percent RH is acceptable. For accurate results use the calcium chloride test method. This involves sealing a test kit to the concrete surface for 60 to 72 hours. Follow the kit instructions for accurate results. Test in multiple locations especially near exterior walls.
What to Do If Moisture Is Too High
Wait for the concrete to cure longer if it is new. Install a vapor barrier underlayment over the concrete. Use 6 mil polyethylene sheeting as a vapor barrier. Tape the seams of the vapor barrier. Seal the edges where the barrier meets the walls.
Vapor Barrier Types
PE film vapor barrier is the most common and affordable option. Combination underlayment with built in vapor barrier is convenient. Rubber underlayment provides both moisture protection and sound reduction.
About PROLEADER
PROLEADER recommends moisture testing before all concrete subfloor installations. Contact us for underlayment recommendations.
