Concrete Moisture & Alkalinity Testing Instructions:
Survey Job Site Conditions
Verify that the building’s environmental controls are operational. The building temperature and humidity should be representative of what it would be during normal use. The temperature should be between 65° F to 85° F or 18° C to 25° C and the relative humidity between 40% and 60% for a minimum of 48 hours prior to conducting tests.
On the first-day preparation will take place. On the following day, the tests should be set and then later retrieved in 60 to 72 hours. The tests need to remain undisturbed for a minimum of 60 hours and a maximum of 72 hours.
Test Location & Frequency
Place tests throughout the area with some in the middle of the building, at the perimeter, over cracks and joints and especially in area of potential moisture. The tests should be performed at a rate of three tests for the first 1,000 square feet and one additional test for every 1,000 square feet.
Test Site Preparation
Remove foreign substances such as adhesives, curing compounds, sealers and floor covering materials. Before removing foreign substances and/or preparing the test site to verify that the existing materials do not contain asbestos and/or lead. Prepare a 20” x 20” test site by mechanical means (diamond cup wheel on grinder if possible) and leave exposed a minimum of 24 hours prior to setting the tests.
Weigh Calcium Chloride Container
Remove calcium chloride from the packing and weigh with a gram scale capable of measuring 0.1 grams. Do not remove the tape prior to weighing. To assure more accurate results always weigh tests on-site and just prior to setting. Record the weight and time on the dish label. Remove tape from calcium chloride container and adhere to the outside of the dome to check for leaks.
Placing Dome Cover
Remove the dish lid and place underneath the bottom piece. Be careful not to spill any calcium chloride. Place open calcium chloride container on the center of the test site, remove gasket cover and adhere dome to the concrete surface. Press firmly on the flange until the gasket reaches the outer part of the flange. Press on the center of the dome to check for leaks.
Retrieving Calcium Chloride Container
Cut the dome top with a box knife in a u-shape large enough to remove the calcium chloride container without spilling and calcium chloride. Replace dish lid cover, re-adhere tape, and re-weigh. Record the weight and time on the dish label.
Perform Alkalinity Tests (a pH of 7 is neutral )
Perform one alkalinity test for every calcium chloride test. Place a quarter-sized amount of the pre-packaged test solution on the concrete surface. Let the solution stand for sixty seconds and then place pH paper into water and let stand for five seconds. Remove pH paper and immediately compare it to the color chart. The chart is included in the kit. Record pH test results on the corresponding calcium chloride dish. High pH refers to High alkaline soil salts penetrating through the slab. Check with the manufacturers specifications if you are treating or coating the concrete that it is compatible with a high pH above 9.