Moisture Testing of Concrete and Scientific Proof

I was recently hired by a large flooring company being sued for alleged "installation failures", among other things.

When I was engaged, the opposition had several impressive-looking and intricately described methods used to "prove" the installation was defective.

The report itself was nearly an inch thick, intimidating to look at and for those who don't understand chemistry, concrete, physics and the laws of thermodynamics, it could easily persuade someone to pay up the hundreds of thousands sought by the building owner.

After reviewing this ponderous report, I picked out three areas of the report where those conducting the testing, undermined their own claims by mis-citing what constitutes "moisture content" in concrete and WHY the flooring failed. NOTE: There were so many irritating and incorrect methods and "conclusions" within that report, I had to sit down and write out the notes, then force myself to concentrate on the path of least resistance when it came to explanation and proof.

Their methodology included RH (Relative Humidity) Probes and claimed the "precisely measured" values indicated excess moisture in the concrete.

1. The "precise measurements" were well outside the listed and stated capacity of the RH Sensors, which are accurate ONLY between 10%-90%. The claimed humidity readings were between 93-97%. Note: The sensor manufacturers and subsequent field tests ALL conclude that ANY RH reading greater than 90% is imprecise/unreliable, this is NOT "my opinion", it is the stated capacity listed by the manufacturer and proven in field studies. The opinion lies with the over-enthusiastic salesperson who convinces those using and relying upon these devices the measurements are accurate above 90% and even encourage this misinformation!

2. Humidity is water in its gaseous form and is ONLY measurable in an open space.

3. Moisture volume of humidity in the conditions of the tested environment constitutes upwards of 0.07 lbs. water per cubic feet of airspace.

Humidity measures where the concrete isn't; since absorbed, adsorbed and liquid water are NOT measurable with a humidity measurement.

This alone undermines the claim of "concrete moisture content". The moisture content of concrete is actually any moisture in the absorbed, adsorbed and liquid form. Note: The difference between including the water in vapor form within concrete has virtually no bearing on the total percentage of concrete moisture content!

Humidity measurements in and of themselves are dependent upon knowing the volume of airspace being measured...since airspace within concrete is unknowable, the volume of moisture even isolated to airspace, cannot be calculated or even reasonably estimated.

Even if known, it takes very little moisture to create high humidity...in a cubic meter of space at 75oF, it would take slightly more than 264 gallons of LIQUID water to fill that space...enough for 10-11 showers.

Contrast THAT when reaching a humidity of 100%, would take less than two ounces of water.

The "trick" used in the report, which may have been borrowed from the "Climate Change Handbook" was to focus strictly on the humidity percentage. Similarly where CO2 constitutes less than 0.05% of the atmosphere, humidity makes up a minuscule portion of the actual moisture content of the concrete. Note: In past articles, I have shown solubility curves of saline solutions. If one were to isolate the solubility curve of sodium chloride and place it next to a solubility curve of sodium hydroxide, if you weren't paying close attention to the scale, they could appear as very similar in solubility. However, if you place the solubility curve of sodium chloride compared with sodium hydroxide using the sodium hydroxide solubility scale, the sodium chloride "curve" would appear to be a nearly flat line.

I cannot emphasize enough....ALWAYS get the context of ANY study, find who funded the study and who benefits.

I was informed the opposition report cost $10,000.00 and was in my opinion, a waste of paper.

Even when this test report was proven wrong, there was stiff resistance in recognizing there was no viable claim, not wanting to admit that for all the expenses, the owner wasted their money. NOTE: for obvious reasons, I can't give any details, but if I were advising that owner, I would tell them to sue the testing agency. Too many are not being held accountable for expertise they do not possess.

Here's the rub..the approach used by the testing agency WAS scientific and without the misinterpretation of the data, could have provided some value, BUT...the problem was the science was misrepresented, misapplied, misdiagnosed and rife with errant conclusions.

Science-based anything that is misapplied will ALWAYS be misleading, even if conducted with a technically correct methodology!

A bullseye is of no value if you aim at the wrong target!

Worse, MANY experts do not understand what the target actually is!

If the industry would listen and then learn what the issue truly are, the billions in yearly claims would virtually cease.

To put it another way, it has been estimated that these claims (directly and indirectly) may reduce profitability by 4-10% (depending upon the floor covering type).

Imagine if that 4-10% were re-added to profits...

It bears repeating, I would readily exchange my consulting fees for a percentage of the savings in a single year for any of the flooring manufacturers.

This can stop...but only if each installer, inspector and manufacturer is willing to accept what is being done, isn't working and what CAN be done, is proven to be work.