Thermal Moisture Scans for Commercial Roofs

Thermal moisture scans can give you some helpful insights into your commercial roof. They can be a vital tool for helping understand what is below the surface of your roofing membrane.

We will go over some of the most common questions about these scans and how they might be of benefit to your situation.

Who Should have a Thermal Moisture Scan?

First, thermal moisture scans can give valuable insight into your roof whether you are having issues or not. A few benefits:

These scans can help identify problematic areas underneath the membrane where water is saturating the insulation (more or that below).
They can be used to catch issues before they become a leak in need of a more expansive repair. Also, focusing on areas more prone to leaks when taking the scan is wise.
And finally, they can give you peace of mind by confirming there are no issues underneath.

Thermal scans are also more beneficial for certain situations than others. Here are a few likely candidates that could benefit from a thermal moisture scan:

Older roofs nearing the end of their life. You can have a scan done to see if any of the roofing membrane is failing and leading to wet insulation. Check out our recent post on How Long Does a Commercial Roof Last for life expectancy for different roofing systems.
If you notice there are areas of standing water or areas of the roof that are sagging.
As an inspection before purchasing a new commercial building. This can give you insights into what’s underneath the surface before the investment.

What is a Thermal Roof Scan?

Thermal moisture scans are taken with a camera that can visually read infrared light due to heat radiation. They can be taken with handheld scanners or put on drones and flown over roofs.

The images are redder on the scanners where there is more heat.

Thermal Moisture Scan can highlight potential problem areas underneath the surface. In the image above, you can compare the two in order to see where most of the heat radiation is coming from.

Here is where it is important for commercial roofs: if water penetrates into the insulation of the roof, the water is absorbed.

Wet insulation captures and retains more heat from the sun. This in turn leads to those areas of wet insulation displaying redder images on the scan. This is especially the case as the sun sets and the roof’s surface cools and the wet insulation retains the heat.

The benefit of this is that you can see where there could be roof leaks on your membrane that have made it into your insulation. There may not be any signs from inside your facility that the roof is leaking.

To make sure this is the case and to see how bad it has gotten, you can take a core in those areas.

A core is when a commercial roofer uses a tool to prod into the roof’s membrane and insulation to see what the roof system is made of and its condition. Importantly, the core can tell you if there is moisture in the insulation for a fact.

When to Have a Commercial Roof Thermal Moisture Scan?

It is important that the weather is right for a scan. Here are a few things that are needed:

Temperature: Weather that is at least above 50 degrees Fahrenheit most of the day. The higher the better.
Time of Day: The scan needs to be taken towards the end of the day, just before night or at night. This depends on how warm it was during the day. If it was a very warm day, you will need to do it a little later to allow the surface temperature to lower. If it was a mildly warm day, waiting too late may cause the heat from the insulation to cool off too much since it was never able to get very warm to begin with.
Weather: The day needs to have been clear. More direct sunlight on the roof leads to any wet insulation absorbing more heat and getting warmer.
Surface Condition: No rain. A wet surface within the past day or two could throw off the readings. It would be harder to tell if it is the insulation or the wet roof elevating the roof’s surface temperatures. Likewise, there needs to be no ponding on the roof.