Look at the wall surface carefully.
How to test for moisture in concrete walls.
Testing with either method will tell you how precisely how much moisture is present making it possible to choose a surface flooring that is appropriate.
9 and or plastic sheet tests astm d4263 test method for indicating moisture in concrete by the plastic sheet method.
Tape a 12 inch by 12 inch piece of plastic wrap onto a part of the basement wall.
A definitive test that measures the amount of moisture released from the concrete requires a calcium chloride kit or a relative humidity meter.
One way to check is to use a moisture meter that is optimized for building inspection work like the bd 2100.
In 2016 the society for protective coatings sspc expects to publish a new guidance document field methods for the determination of moisture in concrete and masonry walls and ceilings that will describe the types of instruments used for determining moisture content.
The sheet is left in place for 72 hours then a dewpoint hygrometer is used to test the level of moisture that is in the air under the sheet.
Determinations need to be made using instruments fig.
Then use the meter to test the rest of the concrete if a reading is significantly higher than the sample you tested then that section of concrete is probably wet and needs more exhaustive testing per the astm f 2170 standard.
It is vitally important to test your concrete slab s moisture before installing flooring over it.
The easiest way to test for moisture in concrete is to duct tape a 2 foot square piece of plastic right to the concrete floor.
Seal the edges of the plastic wrap with tape.
Check the plastic for the next several days noting when moisture.
The plastic sheet method was developed by astm international and involves taping a plastic sheet to the surface of the concrete to create a vapor proof seal around the plastic.
Only tape the edges but make sure they are sealed really good to the concrete.
Check for surface discoloration such as yellowing material.
Reference scale moisture meters can provide a quick and reliable wet dry indication for concrete.
Rh probes are embedded into the slab or inserted through small drilled holes.
Visual inspections are not adequate.
Consider using pinless moisture meters.
This method indicates the moisture condition throughout the slab.
Simply test a bit of concrete you know to be dry with the meter and make a note of the reading given.
This particular moisture meter is ideal for checking the moisture content of walls because it has reading scales for both drywall and wood that allow for precise quantitative moisture measurements in these materials.