Concrete Moisture Test
A concrete moisture test is essential when you have a new concrete floor poured and are ready to install flooring. An important step to remember is to make sure that the new concrete floor has the proper moisture level. Certain adhesives used when installing floor coverings are sensitive to moisture, and will fail if too much moisture is present in the slab. Excess moisture can also delaminate wood flooring and cause distortion and discoloration of other types of floor covering.
Unreliable Concrete Moisture Test Options
There are many methods for performing a moisture test for concrete. Here is a brief description of some of the tests which are used frequently:
The methods listed above are not scientific and have a very high margin of error. There are two methods for moisture testing concrete which are reliable.
- Visual Appearance: Just as its name says, judging the moisture level by the appearance of the concrete surface.
- Concrete Age: The moisture level estimated based on the age of the concrete.
- Rubber Sheet/Plastic Mat: A sheet of plastic or mat is place on the concrete for a period of time after which it is examined for moisture.
Better Options for Performing a Moisture Test for Concrete
Calcium Chloride Test
The first is the ASTM F-1869 Calcium Chloride test. This is the only method which accurately tests the rate of vapor transmission within the concrete. The calcium chloride concrete moisture test measures vapor transmission by determining the amount of weight gained in a sample dish from a prepared area of the concrete surface in a certain amount of time.
Relative Humidity Test
The second test, ASTM F-2170, is concrete slab moisture test that measures the slab’s relative humidity. This concrete floor moisture test is performed when a hole is drilled in the concrete and a sensor is inserted into the hole to measure the slab’s relative humidity.
Both of the calcium chloride and relative humidity tests are needed to achieve an accurate reading of a concrete’s moisture level.
Steps to Perform an Effective Concrete Moisture Test
It is important to take some crucial steps to ensure the accuracy of these tests. First of all, it is necessary that the building be fully enclosed. Secondly the inside must be acclimated to the expected climate of its intended use (this includes the presence of an operational HVAC system). In addition the tests must be performed on several locations to achieve an accurate reading of the entire slab.
The validity of any moisture test is contingent of the installation of a vapor barrier directly beneath the concrete slab. Even if the moisture level is at a level suitable for the intended floor covering at the time of installation, water vapor still may migrate through the slab from the soil beneath. In order to prevent this it is necessary to install a vapor barrier directly beneath the concrete slab.
EcoFoil’s under concrete insulation is a perfect solution for preventing moisture from entering the slab because it is a Class I Vapor retarder with a permeability rating of less than .02 perms. This makes EcoFoil’s under concrete insulation a true vapor barrier. The presence of a true vapor barrier will not only protect your flooring it reduces problems with basement moisture that can lead to air quality issues which are harmful to the health of you and your family.
EcoFoil’s double bubble design makes it a much more durable barrier than standard polyethylene, which is easily punctured by foot traffic while on the job site. In addition to being an excellent vapor barrier, EcoFoil's under concrete insulation has an R rating of 3.8 and reflects up to 57% of radiant heat when installed under concrete. Not only will EcoFoil’s under concrete insulation make your home healthier but it will also make it more energy efficient.