Testing with Moisture Meter
All concrete sub-floors can also be tested using a Delmhorst moisture meter, Tramex Concrete Encounter or Wagner Concrete meter. (Check floor in several areas). Test at each outside wall and 1-5 times in center area depending on the size of room for residential, and at each outside wall and every 6’ in center area for commercial.
Tesing without Moisture Meter
Polyfilm : One test per 200 sqf. (minimum 2 tests per jobsite)
Completely tape down 2’x2’ polyfilm squares and leave them for 48 hours. Check for condensation under the plastic. Condensation indicates slab has moisture. Noticeable color changes indicates moisture.
Phenolphthalein : One test per 200 sqf. (minimum 2 tests per jobsite)
Chip small section of concrete off floor and apply 3% Phenolphthalein in alcohol solution (available at most druggists) in the area. Red color indicates moisture. ALWAYS chip concrete as this protects against the possibility that a concrete sealer was applied. Keep phenolphthalein out of direct sunlight. Average shelf life of Phenolphthalein in 6 months. If any of these tests indicate moisture is present in the slab, the calcium chloride test should be run.
Calcium Chloride Test : One test per 1,000 sqf. for 24 hours. See details for NWFA Moisture Testing Procedures.
If calcium chloride test resulted more than 3 lbs, or moisture is present, DO NOT install, find the source of moisture and correct it.
Tools & Materials:
Hammer, Power saw, Chalk line, Flooring nails, Tape measure, 15 lbs. asphalt felt, Flooring cleaner, Moisture meter.
* 15 lbs. asphalt felt is not considered a moisture barrier. Use of extra moisture barrier (6 mil polyethylene film minimum) may be required if necessary.
Recommended Nail : 3-1/4” wide products 5” wide products
: Model 200, 1-1/2”, 20 gage, 85 PSI, U1 PAD with 1 SHIM.
: Model 50P, 1-1/2”, 18 gage, 85 PSI, .200 PAD with 2 SHIMS.
Model 200, 1-1/2”, 20 gage, 85 PSI, U1 PAD with 1 SHIM.
The World's Best and Finest Hardwood Floors