While a visual inspection provides a general idea of the roof’s condition, it may not uncover hidden or underlying issues. To gain a more thorough assessment of wet insulation, infrared photography can be deployed to uncover what the naked eye can’t see. Infrared thermography, also known as thermal imaging, is a non-destructive testing method that utilizes infrared cameras to detect and capture the thermal patterns emitted by an object or surface. Small, hand-held infrared cameras tend to be a good choice for smaller roofs, while ariel infrared photography—if available—is effective with large roofs.

One of the primary uses of infrared thermography in roof evaluation is the detection of moisture intrusion. Wet areas on a roof surface retain and dissipate heat differently than dry areas, creating temperature variations. By capturing thermal images of the roof, infrared cameras can identify these temperature anomalies, indicating potential areas of moisture infiltration. This enables early detection of leaks or areas where water is trapped within the roof system.

Infrared thermography can help assess the energy efficiency of a roof by detecting areas of heat loss or inadequate insulation. Thermal imaging can identify temperature differences between well-insulated and poorly insulated areas, allowing you to pinpoint locations where heat is escaping from a building. This information helps identify areas that require additional insulation or sealing to improve energy efficiency and reduce heating or cooling costs.

By conducting an infrared scan of a roof, the overall integrity of the roofing system can be assessed. The thermal images can reveal potential defects, such as deteriorated or damaged roofing materials, inadequate sealing around penetrations, or compromised flashing. These findings can help identify areas that require repair or maintenance, preventing further damage to the roof and potential water intrusion. It’s an approach that allows for non-contact evaluation of a roof, eliminating the need for physical access to hazardous or hard-to-reach areas. This makes the inspection process safer and more efficient.

Once your visual inspection is complete, drawing up a detailed roof plan is a good next step. GPS systems can speed up this process, especially if you’re drawing plans for a very large facility or complex. Instruments commonly used in the surveying industry can be used to pinpoint roof equipment and leaking areas.

Infrared thermography is the cheapest and quickest method to identify thermal anomalies in the roof. It won’t identify a wet spot in the roof—that must be verified through core testing or a moisture probe. But it will provide a broad view of the roofing system.

Resistance testing and nuclear testing – both are legitimate tests but must be field verified by either a core test and moisture probe or core test and lab testing to determine the percentage of moisture. As you are testing, keep in mind that if 20-25 percent of the roof is wet, it will probably require a tear-off to bring the roof up to code. In particular, the National Roofing Code allows only 5 percent moisture in the membrane and 8 percent in the insulation, which is why it is important in this part of the assessment to determine what areas of the roof are wet and how much.

Peel Adhesion Testing

A peel adhesion test is based on Miami-Dade’s rigorous testing protocols, but its parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications.

With your visual inspection complete and a roof plan in hand, you can verify your findings through a series of testing. If, at this point, restoration seems like it could be an option, a peel adhesion test can be conducted. This test helps determine the viability of coating solutions by assessing the bonding capability of the roof and the need for an adhesive primer.

How to do a peel adhesion test:

1. Make sure that the surface is clean and dry.
2. Apply a base coat of the coating.
3. Embed a polyester.
4. Attach a clip to the end of the fabric.
5. Attach a spring scale to the clip.
6. Pull the scale at a 180 percent angle (the same plane as the roof surface).
7. Test values over 2 pounds/inch width are acceptable for coating applications.
8. Look for points of failure.

This particular test is based on Miami-Dade’s rigorous testing protocols. It’s important to note that the specific test parameters, such as peel angle, speed, and sample dimensions, may vary depending on the testing standards or specifications provided by manufacturers, industry organizations, or testing laboratories. By conducting peel adhesion tests, roofing professionals can evaluate the bonding performance of the roof system, assess the quality of the adhesive used, and ensure that the roofing membrane will be securely attached to the substrate during the renovation.

Core Cutting Testing

Core cutting, while destructive, can be eye opening. It helps validate the visual moisture survey and confirm how many layers of roofing exist. It involves the extraction of cylindrical sections, or cores, from the roof structure to assess various properties such as composition, condition, and performance. Core cutting requires specialized equipment and tools, most importantly a core drill, which is a handheld or machine-operated drilling device designed for this purpose. Once the core has been cut, it is carefully extracted from the roof and transported to a laboratory for further analysis and testing. The specific tests conducted on the core samples can vary based on the objectives of the study, but they may include assessments of material properties, adhesion strength, moisture content, or chemical composition.

It will reveal the type of deck, how many layers of roof there are, and the type of insulation in the roof, which all helps determine whether restoration is a valid option. Or, if you were considering a recover, the core would be able to tell you if there are already two layers—in which case a third could not be applied.

After the core sample has been taken, the hole created by the core drill is patched and repaired using appropriate roofing materials and techniques. This ensures that the roof’s integrity is maintained and that there are no leaks or vulnerabilities caused by the core cutting process. It’s important to note that the core cutting process should be performed by trained professionals with expertise in roofing systems to ensure safety, accuracy, and minimal disruption to the roof structure.

Wind Uplift Testing

Wind uplift testing can be used to determine the state of the membrane—remember that membranes can become decimated by a storm but may stay in place. The next “big one,” however, can finish the job by ripping the membrane completely off the structure. If you are considering a fleece-backed PVC over the top of a granular modified, you can apply your adhesive and do a pull test to determine if the structural components of the roof meet the required uplift codes to put that roof over it.

During the pull test, the force required to dislodge or pull out the fastener from the substrate is measured. This measurement is usually recorded in pounds or newtons. It indicates the fastener’s resistance to the upward forces exerted by high winds, representing its ability to maintain its position and secure the roofing components. As with a peel adhesion test, a pull test is compared against established pass/fail criteria. If the roofing system can withstand the applied uplift forces without failure or significant displacement beyond the acceptable limits, it is considered to have passed the test.

Structural Engineer

Finally, a licensed structural engineer should be retained if there is any evidence of structural failure or additional loading on the roof (condensing units, blowers, metal screens, ballasted antennas, etc.). A structural engineer can assess the condition of the existing roof structure, including the supporting components, such as beams, trusses, and load-bearing walls. They can identify any structural issues, weaknesses, or damage that may affect the stability and integrity of the roof. This evaluation ensures that any renovation or reroofing work is based on a sound and stable structure.

In terms of loading, roofing materials can be heavy, especially when multiple layers are involved. A structural engineer can evaluate the load-bearing capacity of the existing roof structure and determine if it can support the additional weight of a new roofing system. They consider factors such as the materials used, local building codes, and the design of the building. This analysis helps prevent overloading the structure and potential structural failures.

An evaluation by a structural engineer provides an in-depth understanding of the existing roof structure, its capacity, and its compatibility with the proposed renovation or re-roofing plans. Their expertise helps ensure the structural integrity, compliance with building codes, and optimal performance of the roof, leading to a safe, durable, and cost-effective solution for the building owner or operator.