When a water loss occurs, removing the standing water is only the beginning. Moisture can travel into drywall, flooring, insulation, wood, and other building materials, often extending beyond what is visible to the eye.
Throughout the drying process, restoration professionals use moisture meters to locate affected materials and track their drying progress. If you have ever looked at a moisture log and wondered, “what do all these numbers actually mean?” you are not alone and understanding a few basics can make those readings much easier to decipher.
One of the most common misconceptions is that every number displayed on a moisture meter represents a percentage. Some meters provide moisture content (%MC) when measuring certain materials, particularly wood. Other materials are commonly evaluated using a relative or reference scale. For example, if a moisture meter displays a reading of 65 on drywall, that does not necessarily mean the drywall is 65% water. Instead, it may be a relative reading used to compare one area with another. That is why the type of material, meter, and measurement scale are important when interpreting the results.
One of the first steps is establishing a dry standard, or baseline. A technician takes moisture readings from the same or similar building material in an unaffected area. Those readings provide a comparison for the materials within the affected area. As an example, the moisture reading from a section of drywall in an unaffected area is .4 (this is your dry standard). When daily moisture readings are taken from the affected area the readings are: day 1 – 10.6, day 2 – 8.3, day 3 – 4.3, and day 4 – .3. In this example, the progression from 10.6 to .3 shows that the building material is drying.
Moisture reading, become most valuable when tracked over time. If readings continue to decrease, the drying process is moving in the right direction. If readings remain unchanged or begin to increase, this indicates that the area needs further investigation and the drying plan needs to be altered. Also, it’s important to note that different building materials could have different dry standards. A number that may be significant for one material cannot necessarily be compared directly with a reading from another.
Documenting moisture readings is the most important aspect of the drying process as it helps determine where water has traveled, what materials were affected, whether moisture levels are decreasing and whether drying equipment is performing effectively.
When looking at a moisture log, don’t focus on one number, look at the whole story. At The Gerloff Company, moisture monitoring is an important part of our approach to water mitigation and structural drying. Our goal isn’t simply for a building to look dry. We use moisture readings and documented drying conditions to help determine when affected materials have reached the appropriate drying goals. Because during a water loss, what you can’t see can be just as important as what you can. Until next time my friends, be prepared and stay safe.
Reference: IICRC S500 Standard and “What are the different moisture meter readings scales used for” by Tom Laurenzi.
