Theme: Dry Standard and Quality Documentation
2003 Article
by Ken Larsen
Part One of Eight
Meters are Guides… not Gods
I recently met a colleague from California, we'll call him Joe, who related his challenge with a law suit over a restoration project he worked on four years ago. The project itself was not all that complicated, but it had a tragic outcome: the homeowner died shortly after the completion of the restorative drying.
One of the insurers suspected that the cause of death may have been related to the activities performed during the restoration of the structure. (Of course, there were other important factors to consider - like the fact that the deceased weighed close to 400 lbs! Did this play a role in the homeowner's demise?)
The investigation begins…
Keep in mind that Joe worked this job in 2000/2001, when documentation practices were quite different than they are today. With only a few exceptions, the average professional water damage restorer of that era may have collected a few thermohygrometer readings in the flooded area(s), and a few non invasive meter readings in a structure.
At that time, many restorers felt that if their moisture sensor simply stopped 'beeping', the project was 'dry enough' and they would proudly express to the insured that the job was done. As they carried drying equipment out of the house, the restorer typically gave only verbal assurance to the homeowner that the project was returned to a 'dry standard,' or normal moisture condition.
Would this type of verbal assurance protect our Californian colleague, Joe? His client was now deceased! Who could back him up?
Would this type of verbal assurance protect our Californian colleague, Joe? His client was now deceased! Who could back him up?
One of the first things the insurers investigated was Joe's paperwork. Joe actually wrote down and submitted -- as part of the claim -- some of the psychrometric readings he'd gathered on the project, along with a few moisture content readings from his invasive meters. However, unfortunately Joe had not included conclusions or interpretations in his report. This real-life dispute continues in the courts today.
It is easy to understand how we, as restorers, may cringe as we hear this story and empathize with Joe. What is required from restorers today to protect us from such nightmarish experiences? Joe summed it up in a single sentence: "We needed a more thorough documentation that decisively concluded the structure's return to a safe, dry condition."
Dry Standard and Quality Documentation
What exactly is this 'safe, dry condition' - or 'dry standard,' to many of us - that Joe mentioned? Because it's widely considered to be the most critical element of quality documentation program on every restoration project, 'dry standard' will be a key theme in this article and throughout the remainder of this eight-part series.
Was your project truly restored to a pre-loss moisture condition? Was this reasonably documented to the satisfaction of all materially interested parties? We'll continue to come back to these essential on-the-job questions, as we delve into specific issues related to:
- Understanding meters and some of their limitations
- Drying difficult materials, and evaluating their moisture content
- Drying concrete - an increasing challenge for many restorers
- Determining dry standard. What is 'normal?'
- Communication and documentation
- What is a quality report?
- Should a third party be brought in to inspect your drying efforts?
- What does it take to be an 'expert' that would qualify to be this 'third party inspector'?
Moisture Sensors Have Limitations
Back in the 1970's and 1980's, moisture content evaluation on a water damage loss was, at worst -- evaluated with the technician's hand, and at best -- evaluated with an inexpensive moisture sensor that beeped when it was placed into a suspect material. Clearly, these beeping (and hand) sensors were incapable of detecting moisture levels low enough to reflect 'dry standard'. Regretfully, there are still individuals today who believe that such low-tech strategies will suffice in determining whether a structure has been restored to a dry standard. It certainly would be easy to contest these strategies in a court of law.
Today's formal industry training organizations stress the importance of using high quality, accurate moisture meters to qualify a structure's return to dry standard.
When those beeping moisture sensors were introduced into our industry, there was a painfully slow learning curve in their correct use. The way they work, a sensor simply sends a weak electrical current through two sharp pins. When the two pins are placed into a material that is damp, the circuit is complete and the sensor usually indicates this through sound and maybe even a flashing light. Unfortunately, any contaminant that would complete an electrical circuit would cause the sensor to beep. Urine is one of the most common causes of false positive indicators, as the hygroscopic urine salts would frequently contain enough moisture to start the sensor beeping. For years, this sensor was trusted for testing carpet, pad, the flooring below the carpet, timber… even sheetrock! Virtually everything was 'tested' with these sensors to see if they would start 'beeping,' and evidence of this was apparent with the two resulting holes in all the materials the sensor came in touch with! Frequently a greater devaluing of the material being tested was done with this tool than was the value of the information it provided!
On the other hand, wood sensors used in the restoration industry only begin to 'beep' when the wood being tested possesses moisture content greater than 17% - 19%. This is alarming because wood with 19% moisture content presents enough moisture at a normal room temperature to support several species of mold growth in organic materials adjacent to it. In fact, wood with only a 16% moisture content may present enough moisture to support mold growth!*
Keep in mind that according to the USDA Forest Products Laboratory, the average moisture content found in wood for most of the United States is 8%. Imagine all the projects that were incorrectly deemed to be 'dry standard' - when they in fact had been far from such a target!
Moisture Meters Have Limitations
As a result of this failure to return the structure to an accurate 'dry standard,' the resulting microbial growth was frequently blamed on the restorer. This accountability resulted in very expensive repairs, and great disappointment for all parties involved. In the 1980's and early 1990's, the restoration industry matured and began the use of meters that were able to quantify the moisture in materials. The use of these invasive and non-invasive, (pin type and non-pin type) meters was well received in our industry, but few restorers really studied the owner's manual that accompanied them.
Non-Invasive Moisture Meters
Imagine the value to the restorer as he considered a tool that was able to detect levels of moisture in materials without having to cause those annoying holes that come with the use of a moisture sensor. Why it was like magic! We didn't really know how it worked - but we trusted it with complete faith that what it displayed was 'truth'.
It wasn't until someone stepped forward and actually challenged some of the findings of those who used these meters, that it was realized there is some accountability that comes with the conclusions made by the restorer. Some who incorrectly used these meters left structures wet - and the resulting lawsuits made many restorer's sit up and take notice. Suddenly, the talk within the restoration community was such that these meters were being questioned. What were these meters actually showing the inspector? Many of those using a non invasive meter simply continued with their drying strategy with nothing more of a target than: Dry until the meter stops 'beeping.' Does this sound familiar?
To further complicate the process, there was a weak understanding of how to document what the meter displayed. Many non-invasive meters have an analogue display with two scales. Which scale is referred to on the restorer's paperwork? Did it really matter? How deep does the meter read into the material being tested?
The greatest of errors in the use of non-invasive type meters is the failure to realize that these meters do not accurately detect moisture through an air space. Density of materials skews the meter's readings. Some meters are even skewed by the presence of the inspector's hand. Conductive materials found in or behind the materials being tested may affect the values displayed on the meter. Some meters have more than one setting for use on materials other than wood. Are they in fact calibrated for quantifying the moisture content in these materials (like sheetrock or plaster / brick)? If they aren't actually calibrated for these materials - then how is the meter to be used on such surfaces? A restorer might arrive at an incorrect conclusion due to an inaccurate understanding of the meter's use.
A restorer's careless conclusion based on non-invasive meter measurements alone became easy targets in a court of law. Today's user of these tools needs to understand the meter's functions and limitations better in order to survive.
Invasive Meters
Because of the limitations with non-invasive meters, restorers took a closer look at pin type meters that were carefully calibrated to calculate the moisture content in wood by weight. Although they would put holes into the material that they were testing, restorers believed they would be more accurate in reflecting 'truth' in the evaluation of moisture content.
But careful examination of the owner's manuals showed their limitations as well!
Most of these meters were only calibrated for wood — a certain species of wood from the dozens that a restorer may encounter! Why, not only a certain species of wood, but also the temperature of the wood affected the displayed value. Corrections for the wood temperature - and the species of the wood -- are usually clearly outlined in these owner's manuals. But how many restorers actually go through the exercise of documenting these corrections?
For that matter, what is 'dry standard' — and how is it calculated?
If documentation can be a restorer's salvation — or a demonstration of incompetence… what dare a person put into the project file?
How are the many construction materials found in structures evaluated and dried?
These and other issues are addressed in future articles.
*based on the aW found at the surface of wood with an equilibrium moisture content of 16% at 70º F.
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