Instructor Ed Jones has over 30 years of experience in theindustry, has the title of MasterWater Restorer, is an Institute ofInspection Cleaning andRestoration Certification (IICRC)-approved instructor, and hasserved on the S500-2021consensus body committee todevelop the most recent standard.
Years ago, when we first started Codeblue, now known as Accuserve, I realized that most vendor programs and insurance carriers were not asking for drying logs on water damage claims to prove materials were dried out properly.
Because of this, we started asking restorers to provide psychrometric and moisture content readings when drying structures and contents.
Here we are more than 20 years later, and everyone asks for drying logs. However, I am pretty sure that most adjusters, vendor programs, and even restorers are not really examining the readings and understanding what they are telling us.
This becomes a big deal when allegations arise involving incomplete drying or causing mold, or when an adjuster is trying to validate the length of drying time.
To help address this issue, I developed a guide explaining what I look for when examining drying logs.
This includes a moisture map showing where moisture content readings were taken and how those locations correlate with drying logs and labeled photographs.
Below are my 10 recommendations for "reading the readings" in water mitigation.
The first thing I look at is the psychrometric readings showing the atmospheric conditions inside the structure compared to outside.
This helps determine whether outdoor conditions are favorable or unfavorable for drying.
It also provides insight into how humid and hot the structure is during the mitigation process.
Outdoor conditions that are unfavorable, particularly when the humidity ratio exceeds 70–80 grains per pound (GPP), can slow down indoor drying if the restorer has not established tight containment.
Understanding these conditions is an important first step in determining whether the drying environment is being properly controlled.
Next, I check whether drying chambers were established properly.
The restorer should always establish containment, regardless of the category of water, to separate affected areas from unaffected areas.
Proper containment serves two important purposes:
By focusing the drying process within a contained space, restorers can better control environmental conditions and improve drying efficiency.
Always ask for photographs of all containment areas.
These photos help demonstrate whether the drying chambers were properly established.
Next, I examine the psychrometric readings inside affected areas to identify potential issues with temperature and humidity.
We want to establish the initial conditions on the first day so we can evaluate whether the restorer provided a suitable environment for drying.
We also want to see that the drying conditions improved appropriately each day.
My general rule of thumb is that affected areas should reach:
These are targets, and getting close is a good indication of progress.
However, if these conditions are not reached, the restorer should be asked for an explanation.
Potential issues include:
These measurements help determine whether the restorer is taking steps to enhance drying, minimize drying time, and restore as many materials in place as possible.
Extra days of drying are not warranted if good drying conditions were not provided.
Another important measurement is the grain depression between the affected area's air and the dehumidifier exhaust.
This can help determine whether the dehumidifiers are operating properly.
Grain depression is not the only factor to examine. You must also determine whether good drying conditions were established and whether the affected materials are actually drying.
However, it is an important performance indicator.
When grain depression readings do not appear correct, one of the first things I examine is the temperature of the air leaving the dehumidifier.
As a general guideline in my evaluation, dehumidifier exhaust temperatures should be approximately 15–25°F warmer than the ambient air entering the dehumidifier.
If the readings fall outside the expected range, ask questions.
The technician may not be taking accurate measurements, the equipment may not be functioning as expected, or the readings may have been recorded incorrectly.
Unusual measurements deserve further investigation rather than automatic acceptance.
Another important step is comparing psychrometric readings from different locations.
These comparisons should include:
The goal is to understand how the different environmental conditions influence the drying process.
It is critical to evaluate whether the HVAC system is helping or hurting the drying process.
We should utilize the HVAC system to support drying whenever possible.
According to the IICRC S500 Standard referenced in this article, daily HVAC readings are required.
These readings help provide a more complete picture of the environmental conditions throughout the restoration project.
Penetrating moisture meter readings should be recorded whenever possible because they provide more conclusive moisture content information.
Remember, non-penetrating moisture meters do not directly measure moisture content.
Instead, they help indicate whether a material may be wet.
A non-penetrating meter can be useful as an initial screening tool, but it should be followed by a penetrating moisture meter reading whenever possible.
Always ask for photographs of final moisture content readings.
These photos provide important documentation that affected materials were dried to their established drying targets.
Without adequate moisture readings and photographs, it becomes more difficult to demonstrate that the drying process was completed properly.
Water follows the path of least resistance and travels downward due to gravity.
This means restorers must investigate beyond the areas where water damage is immediately visible.
For example, if a wood subfloor is wet, what is underneath it?
It could be:
The investigation should follow the water's path to identify additional affected materials.
Do not overlook materials that may have become wet beneath or behind the initial area of damage.
Failure to identify and record moisture readings on these materials could lead to future microbial growth concerns.
Show the path of the water and all affected materials on the moisture map.
Sill plate readings are another important part of water mitigation documentation.
If water migrated across the floor from room to room and caused drywall to become wet, the sill plates should also be evaluated.
Wood is an organic food source for mold, making it important to verify that affected wood materials have been properly dried.
My recommendation is to ensure wet wood materials are dried to less than 20% moisture content, using a penetrating moisture meter whenever possible.
Be sure to document sill plate readings in the drying logs and identify their locations on the moisture map.
Overlooking sill plates could mean overlooking moisture trapped in structural materials.
Another important part of reading drying logs is understanding the expected length of drying time for different materials.
I use the following key performance indicators (KPIs) when evaluating drying performance.
MaterialTarget Drying TimeCarpet24 hoursCarpet pad, Category 1 water loss with no vapor barrier48 hoursDrywall2–3 daysSill plates, wood subfloors, and wood framing3–4 daysHardwood floors5–7 days
These are drying targets, not guaranteed completion times.
If the targets are not met, the restorer should provide an explanation supported by the drying conditions, moisture readings, and project documentation.
Understanding these KPIs can help adjusters and vendor programs validate the length of drying time rather than simply accepting the number of days billed.
One moisture content reading for an entire room is not enough.
Multiple readings are necessary to properly document moisture conditions throughout affected materials.
Drywall and plaster wall readings should be recorded by wall number, such as:
This makes it easier to identify which walls were monitored and how moisture levels changed during drying.
I recommend the following moisture reading intervals:
