What is an acceptable moisture level in concrete?

Video Link

3.5 to 4.5 % Moisture Content.

When using a Tramex Concrete Moisture Meter - CME5 and CMEX5 on clean new concrete 4.5% MC is considered "dry" in most conditions. In drier conditions, 4% MC is considered "dry". In Desert conditions generally, 3.5% is considered "dry". These numbers are %MC numbers on our Concrete Moisture Meters that are Calibrated specifically for concrete based on Gravimetric testing.


Our Concrete Moisture Meters read 3/4” deep into the concrete slab giving instant Quantitative results and when coupled with our New Concrete Moisture Probe (the Determinator) can read up to 4” deep in the concrete slab giving correlating %MC readings.


Finally correlating numbers from the surface to deep in the slab allows us the "see" the actual acceptable moisture level of a concrete slab instantly. No more waiting 24 hrs after drilling. The Tramex Concrete Moisture Meters are an essential part of thorough Concrete Moisture Testing and should be a part of every serious tester's Concrete Moisture Test Kit.


The Complete Concrete Moisture Test includes noting Ambient conditions, Temperature, Relative Humidity, and Dewpoint. Checking the Surface Temperature of the slab. Checking %MC in the top 3/4” of the slab with Tramex Concrete Moisture Meter. Checking %MC within the slab using the Tramex Concrete Moisture Probe and then in the same hole Checking in-situ RH% following ASTM F2170 guidelines. This will give you the clearest picture to make the most complete determination of acceptable moisture levels in concrete when applying Floor Coverings or Coatings.


Below is the transcript of the video interview with Robert Higgins - Tramex Talks

David: Hi Bob.

Bob: Hi David.

D: Thanks for joining us again on Tramex Talks.

B: Thank you for having me.

D: Today's question is: what is an acceptable moisture level in concrete?

B: What I found, if you use a Tramx meter, most of the time unless you're in the desert, about 4.5% it's fine. 1.5% lower it's fine, that's dry enough. Especially in Florida, 4.5% is real dry. If you getting into the desert areas probably closer to 3.5%.

D: And will that number generally change on older concrete?

B: Yeah, because older concrete gradually becomes dryer and dryer as it continues to develop cement, and the chemistry redistributes, but again this is where you want good concrete practices. If the concrete has not been cured properly, a lot of the problems that we see with newer concrete get worse with age.