Flat Roof Leak Detection – Infrared Scanning Technology

Oct 18, 2021
Flat Roof Leak Detection - Infrared Scanning Technology

The benefits of infrared scanning technology have not gone untapped within the construction and roofing industry. In the roofing industry specifically, infrared scanning is used to locate wet insulation as well as detect possible leak sources. Conducting regular infrared scans narrows the search for water intrusion, without damaging or puncturing the roof, saving time and pinpointing exactly which areas are in need of roofing repairs.

Infrared imaging is a key piece of flat roof leak detection equipment. Infrared scans create detailed maps of commercial and industrial flat roofs, showing where excess moisture is trapped, where the source of a leak may be, or where wet or compromised insulation is. Such scans of your flat roof system can quickly and accurately evaluate the health of your roof without the need for destructive and intensive testing. Infrared scanning is also a cost-effective option when compared to other traditional flat roof evaluation methods.

Infrared scanning helps to capture infrared radiation, a part of the electromagnetic spectrum that is not visible to humans. Under the correct conditions, an infrared scan will capture heat the way a normal camera would capture visible light, creating an image that displays the extent of moisture issues affecting the roofing system. The basic principle behind thermographic technology is that moisture adds thermal mass to the roofing material, which makes it hold onto heat longer than the dry material next to it. The infrared scan assigns colours to different temperatures, allowing for an easy to read and clear image of any moisture affecting your flat roof. The more heat in an area, the brighter that area will appear in the resulting image.

Utilizing infrared technology allows commercial and industrial building owners to be proactive in stopping potential damage that can affect the building’s interior. Infrared scanning is a great resource in evaluating the overall health of a commercial or industrial roof without random or destructive testing.

Infrared scanning is an important technology that is very beneficial in diagnosing issues with your commercial or industrial flat roof. Here’s what you need to know:

Importance of Infrared Scanning

Before infrared scanning was available to roofing professionals, methods such as electrical impedance testing, nuclear moisture testing and flood-testing were used. Such technologies were time-consuming, intrusive and expensive guesswork. Utilizing infrared scanning as an alternative will provide accurate information in a timely and inexpensive manner.

Infrared scanning offers building owners significantly more information about exactly where moisture is hidden, even which specific layer of the roof the moisture is affecting, and which areas of the roof are still dry and functioning. Building owners will save a significant amount on their investment as an infrared scan will tell you exactly what to replace, saving you time and money by minimizing tear-offs.

Infrared scanning is also useful for large corporations or businesses where many people are involved in the decision-making process. Such advantages include:

  • Reports: Produces maps that can be included in reports about the roof’s status.
  • Budgeting: Such maps can help plan your budget and estimate the costs of a roof repair.
  • Roof Leak Detection: Maps can be used to detect leak sources as well as other insidious and dangerous issues, such as formation of mold or moisture erosion of the roof deck’s structural integrity.
  • Determining Rates: Insurance companies may also take infrared maps into account when assessing real-time conditions of the building and determining rates.

How Infrared Scanning Works

Heat gives off infrared light. The more heat in an area, the brighter the resulting image will appear. An infrared scan will assign colours to different temperatures which allows for an easy to read and clear image of any moisture in your commercial or industrial flat roof. While some infrared scanners assign images in black and white, there are computer software’s that will make the difference in temperature more profound. Simply put, infrared imaging captures light, the same way a smartphone would capture visible light.

How Infrared Scanning Works

Such technology will detect temperature fluctuations within your flat roofing system. When fluctuations in roof temperature occurs, this can be an indicator that the roof is holding moisture which can lead to serious damage and leaks. By incorporating infrared scans into your regular flat roof maintenance routine, you are able to make preventative repairs before potential damage occurs.

How Infrared Scanning Inspections Find Moisture

Water adds thermal mass to objects. Wet roofing insulation soaks up more heat from the sun during the day. At night, it releases this heat more slowly, appearing warmer in thermal imaging.

There are many elements on a roof that can appear warmer without being wet, such as HVAC equipment and wet flat-roof drains. It is important that an infrared imaging professional determines where these warm elements are before the scan to ensure the final images are interpreted properly. Different roofing materials such as reflective roofing also appears to be wet on the infrared scanner; so, it is also important for an infrared professional to be aware of what material the flat roof is made up of.

How Infrared Scanning Inspection Find Moisture

Furthermore, because an infrared scanner detects heat from excess moisture, the results of the imaging must be confirmed. Typically, this can be done by using a non-penetrating moisture meter.

A non-penetrating moisture meter is a non-invasive tool that finds moisture in the roof without cutting into the membrane. Rather than checking an entire commercial or industrial roof, this type of technology is best suited for performing spot checks. Utilizing a non-penetrating moisture meter will confirm the findings of an infrared scan, helping to prevent unnecessary replacement of roofing materials.

moisture meter

When can an Infrared Scan Be Performed on Your Roof?

The conditions to conduct an infrared scan must be just right in order to achieve an accurate reading. Based on the conditions and climate, there are two types of scans an infrared scanner can employ: warm weather scans and cold weather scans.

(1) Warm Weather Scans

In warm climates, infrared scans are used to read the difference in temperature between wet and dry roof insulation. To conduct a warm-weather infrared scan, the sun must be set. Throughout the day, the sun will have heated the roof, also heating any wet insulation. As the sun begins to set, the dry portions of the roof begin to cool while wet areas will hold heat. The infrared scan will then pick up “hot spots” that are holding moisture.

(2) Cold Weather Scans

Cold weather scans are typically performed during cold weather, however, they can also be performed during the early morning depending on the temperature. This type of infrared scan is based on the difference between indoor and outdoor temperatures and relies on the internal heat of the building to warm up the roof. When the inside of the building is warmer than the air outside, wet insulation will transfer more heat out of the building than dry insulation.

As for when to conduct an infrared scan of your roof, the general recommendation is to get a scan twice a year, once in the Spring and again in the Fall.

However, there are four other times that an infrared scan is also recommended:

  1. After severe weather (rain, snow, ice).
  2. If you suspect a leak in your flat roof.
  3. When purchasing an existing building.
  4. After the installation of a new flat roof.

Thermal Imaging Cameras are a Must-Have for Commercial Roofing

There are many applications for thermal imaging, and so there are many different types of cameras available within the market. In the commercial and industrial roofing industry, the ideal thermal camera should be highly heat-sensitive and capable of detecting a single degree difference. It is also important that the camera yields a wide-angle lens and provides high spatial resolution.

Thermal Imaging Camera is Must-Have For Commercial Roofing

The images that this camera takes will show not only the moisture, but enough of the roof that a roofing professional can use them as a guide to find the exact location of the moisture. The camera must measure midwave arrays (3-5 micrometres) over longwave arrays (8 micrometres and more). This will ensure that any reflective materials on the roof or its insulation are not distorted during the scanning process.

How Roofing Material Affects Infrared Scans

While infrared scans are great technology and incredibly useful in the roofing industry, not all commercial roofing materials are suitable for an infrared scan. Infrared scans can only be used on certain commercial or industrial flat roof types, under specific weather conditions, and at specific times. In fact, some roofing systems make it next to impossible for an infrared scan to even be useful.

There are commercial roof systems and materials that are incompatible with infrared roof moisture scan methods, such as:

  • Roofs with concrete decks.
  • Inverted or protected roof membrane assemblies.
  • Certain insulation types, including foam glass and closed-cell foam, such as polyurethane.
  • Metal roofs, especially those with reflective coatings.
  • Vegetative roofs.
  • White roofs or those with foil-faced insulation assemblies.
  • Heavily ballasted roofs.

Roof systems and materials that make infrared roof moisture scans more challenging include:

  • Foil-faced insulation.
  • Protective Membrane Assemblies (PMA).
  • Roof systems that are white or lightly coloured.

On top of that, there are other elements of the roof or building that can affect the infrared scan:

  • Ponding on the roof.
  • Heat-Producing Equipment: This equipment can simply be turned off a few hours before the scan.
  • Ballast on the roof.
  • Previous Repair Jobs: If the roof is made up of different materials, this may affect the scan.

Four Different Methods for Conducting Infrared Scans of Roofs

There are four methods in which an infrared scan can occur:

Aerial Method

This method includes taking infrared footage from an aircraft or drone. Utilizing the aerial method has many advantages as the roofer can create a whole map of a roof, even if the roof is large in size. A powerful and high-resolution infrared camera is necessary for this method as the further you get from the roof’s surface, the more the heat disperses, making the readings more challenging.

Aerial Method

The aerial method is best suited for roofs that are inaccessible, dangerous or very large. Drone technology has made aerial scans quite convenient as they are cost-efficient and can scan multiple roofs in one session.

Prior to conducting an aerial scan, the building owner and infrared imaging professional should examine the roof for sources of heat, flashing and penetration details, access points, and any safety hazard. This will ensure the infrared imaging professional is well-equipped to interpret the results of the scan while staying safe through the process of performing the infrared scan.

On-Roof Method

On-Roof Method

The on-roof method involves taking images while standing on top of a flat roof. When conducting this type of scan, the infrared professionals will mark any areas of moisture with paint so that it is easier to find them again later.

Under the Roof Method

This type of scan must be performed from the inside of the building. This method is the most labour-intensive as all obstructions must be out of the line of sight to the roof. In addition, this is the only method that is used for metal roofs.

Under the Roof Method

Once all obstructions have been cleared, simply point the infrared camera at the roof. Due to this method’s limited angle of view, multiple images will need to be taken at the time of the scan. Furthermore, you will have to record the positions of these images to find any revealed moisture later. Since these scans do not include roof landmarks, roofing professionals use such images to guide their repair efforts when they are on top of the roof.

Elevated Vantage Point Method

Elevated Vantage Point Method

Conducting an infrared scan from an elevated position can make the images easier to understand later. This method will capture a large portion of the roof’s surface, including any features that can be used as landmarks to guide the repair efforts. Taking photos too close to wet areas is a common mistake among infrared professionals, and this method helps to prevent that.

Allow Professionals to Fix Your Leaking Roof

Infrared scans are a major asset to commercial and industrial flat roof building owners as they help to maintain the roof and spot repairs before damage occurs. An infrared imaging professional can advise you on if your roof is a good candidate for an infrared scan, which kind of infrared scan will give you the best results and when you can expect the right conditions to conduct the scan.

Once you have conducted an infrared scan, you can then contact a qualified roofing company to perform the necessary repairs. For all your flat roof needs, D’Angelo & Sons Roofing & Exteriors is here to help! For more information on infrared scanning or flat roofing, call us today at (905) 387-3000.

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