09-02-2009, 08:14 PM
I'm investigating a surface moisture problem on finished concrete floor. Here are the details.....this is a perimeter room section of a larger building and this room has had an addition in the past year. The floor is about 6 inch concrete covered with a commercial grade vinyl floor tile. The building manager says that when they come in the morning the floor is wet and this started about six weeks ago. I have ruled out a plumbing or visible roof leak and the HVAC technician says the A/C is working fine. Relative humidity (air) with the A/C running is about 50% . Rain in the time period has been above normal but drainage appears good. The manager also says the problem started after the floors were freshly stripped and waxed. Right now I'm thinking surface condensation or moisture rising from the concrete added during the addition. I've not performed a probing for concrete RH yet. Expert advice appreciated.