Remember when you had to physically climb a roof to inspect it? In fact, many still do. Licensed contractors look for issues related to wear and tear, storm damage, and general maintenance needs – so that they can provide assessments and recommendations for repairs or replacement. Home inspectors check out the condition to aid during the valuation process and help potential buyers gauge the state of the home. Insurance adjuster come in after incidents like storms, fires or other kinds of cases to determine the extent of the damage and verify insurance claim. Engineers and architects need to see if the roof meets the local building codes. Whichever the profession, they all have to find a way to get up there and do their job.
Problems Galore
The climb comes with risks of falls and injuries, especially with traditional methods like using extension ladders or telescoping ladders to reach the eaves of roofs. Similar case when using rope and harness systems, where everything depends on how well the safety line has been anchored, and how secure the point selected is. For higher or more complex roofing projects, scaffolding can provide a stable platform especially when dealing with multiple workers – but then extensive equipment is needed.
Aerial lifts or cherry pickers may be employed, enabling the professionals to get to the roof though a platform operated by a hydraulic lift system, but then that comes with so many logistical hurdles, and not to mention costs. Of course there are some commercial buildings that have built-in access through roof hatches, where anyone can get to the roof form inside the building through a fixed ladder or staircase. Once you’re actually on the roof, the same risks of falls apply.
With such logistical headaches, costs and risks of accidents, its easy to see why professionals carrying out roof inspections gravitate towards using drones. With the UAVs, the entire task can be carried out from the safety of the ground – for a fraction of the time and cost.
4 Key Benefits Of Drone Roof Inspections
1. Safety Factor
All manner of accidents can happen when physically carrying getting to the roof. Falls from slipping, tripping, or losing balance, especially on steep or wet roofs. Some are caused by improper ladder setup or failure. Tripping over roofing materials, tools, or uneven roof surfaces that may not always result in a fall off the roof but can lead to other injuries such as sprains or fractures. Electrocution from contact with overhead power lines or exposed electrical wiring. Ther can even be accidents with the tools, whether it is by improperly handling them while on the roof, or dropping them and injuring the people below.
Walking on a particularly damaged or weak roof can cause sections of the roof to collapse, leading to potential injury for the inspector and further damage to the property. Strains or other musculoskeletal injuries from hauling heavy equipment as you move up and around the roof, heat stoke and dehydration for those cases where the roof inspection is being carried out for long hours in hot weather – there are all sorts of issues that one must contend with. With drones, you drones, you don’t have to worry about this. Simply pilot the drone with camera over the desired area of the roof and get the visuals – photos and videos – needed for the assessment process.
2. Cost and Time Efficiency
Manual inspections are limited in different ways. Setting up ladders or scaffolding takes time and can be labor-intensive. Carrying out a thorough inspection on larger or complex buildings takes loads of time. Inspectors might miss even subtle signs of damage or wear that can lead to bigger problems if not addressed early. Ensuring safety during roof inspections often involves extensive gear, insurance costs, and potentially even road closures (for using large lifts or cranes), all of which add to the expense. And you also have to carry out the task slower due as you take extra care to avoid accidents.
You also need the weather to be just right before risking life and limb on the roof. Bad weather means delayed inspections, leading to scheduling backlogs and increased costs. Keeping in mind that multiple site visits are often necessary—first to diagnose the problem, then to fix it, and possibly another to confirm that the repairs are adequate. And each visit incurs travel time and costs, and coordination effort with multiple workers and equipment involved.
Drones for roof inspection minimize the need for extensive equipment, and they cut down on both preparation time and labor costs. These UAVs can quickly cover large areas, capturing high-resolution images and videos, thus expediting the process.
The data can even be transmitted live, allowing real time decision making by other stakeholders – such as for cases where the inspection is part of a large scale construction project. And with long range drones like the Matrice 350 RTK which can remain airborne for up to 55 minutes, you get to obtain more data with each flying cycle. It can handle a range of payloads and offers a wide choice of cameras such as the Zenmuse H20T with its 20MP zoom camera, 23× hybrid optical zoom and 640x512px radiometric thermal camera.
The M350’s dual-battery system supports hot-swapping, meaning the roof inspectors can replace the batteries without powering off the drone. And the batteries themselves -TB65 Intelligent Flight Batteries - come with a 5880mAh capacity and for 400 recharge cycles, which translates to fewer operational costs. Those roof inspections can be carried it out during challenging conditions given that the M350 is IP55-rated for water and dust resistance, can be flown in conditions from -20° to 50° C, and even withstand 12 m/s wind speeds.
The Teledyne FLIR SIRAS also has hot-swappable batteries, clocks a 31-minute flight time, and takes off in under 60 seconds. This IP54-rated drone features a 16MP camera with 128x zoom, and doesn't have geofencing – so ensure that you're flying it in permitted zones during roof and building inspection tasks.
3. Enhanced Data Collection
Roof inspection drones are not a set of high-flying binoculars. High-resolution cameras and drones with thermal imaging enable you to get detailed views of the roof’s condition, detecting problems like leaks, insulation issues, and structural damage that might not be visible to the naked eye. For instance, the Zenmuse H30T gets you images with a 1280x1024 resolution, and can measure temperatures from 20°C to 1600°C. This payload is compatible with DJI Matrice 350 RTK and Matrice 300 RTK drones and operated via DJI RC Plus.
The kind of data obtained depends of the camera payloads used, which is then analyzed using the integrated software. Different zoom cameras and sensors are available for the task, and you get greater accuracy than doing it manually. Here is a quick overview of the imaging technology used for roof and building inspections:
• Thermal imaging: Infrared cameras on the drones allows for the non-invasive detection of moisture, heat leakage, and other potential issues in roofing materials.
This method relies on the differences in thermal properties between wet and dry insulation. Typically, wet insulation retains heat longer than dry insulation, which can be visually identified in thermal images taken after sunset.
These differences are detected because wet areas cool down slower than dry ones, creating a clear contrast visible in the thermal images. And with tech like the quick-connect Vue® TV128 radiometric camera payload of the Teledyne FLIR SIRAS drone, you get to combine thermal images with visible-light outlines in real time due to its patented MSX® technology.
For optimal results, thermal imaging inspections should be performed under specific conditions. It is ideal to conduct these inspections after a clear, sunny day as solar heating helps accentuate the thermal contrast by sunset. Furthermore, conditions should include minimal wind and a dry roof surface to avoid misinterpretation of thermal patterns caused by external moisture like rain or dew.
• LiDAR: During a LiDAR-based roof inspection, drones equipped with LiDAR sensors like the Zenmuse L2 emit laser beams that bounce off the roof and return to the sensor. The time it takes for the light to return is measured and used to create detailed three-dimensional models of the roof. Drones with LiDAR sensors can capture detailed information about a roof's geometry, including its dimensions, pitch, and condition, which is particularly useful for tasks such as evaluating a roof' s suitability for solar panel installation or assessing damage for insurance claims. The data collected can include measurements of valleys, ridges, and other structural elements that are crucial for maintenance or installation projects. Additionally, the ability to create 3D models helps in visualizing the roof's condition and planning any necessary repairs or upgrades.
• Photogrammetry: Here the drones obtain high-res images from various angles, which are then processed to create detailed 3D models of roofs. The process starts with a drone capturing a series of overlapping images of the roof using a payload like the Zenmuse P1. These images are processed using specialized software like Pix4D or DroneDeploy, which analyzes the photos to calculate depth and reconstruct the 3D scene. This results in a dense "point cloud," which can be further processed to produce igital Elevation Models (DEMs), Digital Surface Models (DSMs), and orthomosaics. Orthomosaics are especially useful as they correct distortions from camera tilt and topography, providing scale-accurate images.
For effective photogrammetry, it's crucial to ensure substantial overlap between images and to cover all angles of the roof. Software tools not only help in stitching these images together but also in creating textured 3D models that offer a realistic visual representation of the roof. These models are an asset for everything from the roof inspections, solar panel installation planning, to insurance assessments.
Also Read: RGB, Multispectral, and LIDAR Imaging Tools For Farmers
4. Access to Difficult Areas
The valleys, or the areas where two roof planes meet, can be particularly difficult to access safely using traditional methods. These are critical areas for water runoff and are prone to leaks. For roofs with solar panels, the panels may obstruct the view and access depending on the angle you’re approaching them from. Getting edges of roofs and ornamental cornices can be dangerous, especially on tall or steeply sloped roofs, yet they are some of the areas that are more susceptible to wear and damage from the elements. You can’t just skip them.
Features like skylights, vent pipes, and other installations can create nooks and crannies that are hard to inspect closely without directly accessing the roof. Even with the gutters and downspouts - while not directly on the roof, can be cumbersome to deal with, especially if they are high or obstructed. In urban areas or crowded neighborhoods, the space between buildings can be so tight that accessing the sides or backs of roofs can be nearly impossible without specialized equipment. Older buildings with historic value or roofs made from fragile materials like clay or slate tiles are particularly challenging. Walking on these roofs can cause damage, so they require non-invasive inspection methods.
Drones excel in navigating such tough-to-reach spots including as tight corners, and areas around protrusions like chimneys and vents. Their ability to fly and maneuver in diverse conditions allows them to capture detailed visuals of parts that might be inaccessible or dangerous for a human inspector to reach – especially with compact drones like the Anzu Raptor T, which weighs around 920g (2 pounds), and comes with imaging features like a 56x hybrid zoom, and a gimbal that gives it a wide range of motion, tilting from -90° to +35° for you to view those tricky angles.
This particular building inspection drone is assembled in Malaysia with critical software components developed by Aloft Technologies in Syracuse, USA. Firmware installation and quality checks are carried out on mainland United States, making it a suitable option for teams concerned about using foreign-manufactured drones.
High or steeply pitched roofs that are notoriously risky, roof with complex designs or multiple levels that add to the logistical challenge of equipment setup, large buildings or properties that cover extensive areas – accessing them with drones is a breeze. The imaging payloads can also identity cracked tiles, broken shingles, pooling water, and other damage signs without requiring direct contact.
The Drone Roof Inspection Process
Here is a quick overview of each phase to help property owners, engineers, insurance agents and other professionals achieve the best results during roof inspections with a drone.
Step 1: Preparation
Equipment Check: Ensure the drone’s batteries are fully charged, the memory card has sufficient space, and the camera settings are adjusted for optimal image capture. It’s also essential to inspect the drone’s physical condition, checking elements like propellers and sensors.
Weather and Airspace Check: Confirm that weather conditions are favorable and check for any airspace restrictions that could impact the flight.
Step 2: Safety Measures and Legal Compliance
Secure a Safe Operating Area: Establish a safe perimeter around the inspection site to prevent any accidents in case of drone failure.
Legal Compliance: Ensure all necessary permissions and certifications are in place, such as the FAA’s Part 107 certificate for commercial drone operations in the U.S. Read more about this here: What Does Having a Part 107 Drone (UAS) License Mean?
Step 3: Planning the Flight
Use the drone’s flight software to design a path that offers multiple perspectives and covers all areas of the roof. This step should include setting the drone’s flight height and camera angles to capture the necessary data.
You can plan flight routes and missions when flying roof inspection drones like the DJI Matrice 30 using FlightHub 2. Upgrading to Live Mission Recording gives you an optimized user interface, complete with task recording and target point marking - that way you ca save 90% of operation steps. You can adjust the Gimbal angle and photo settings between Waypoints for better efficiency during the task.
Step 4: Executing the Flight
With the planning complete, it’s time to fly the drone. During this phase, the drone captures high-resolution photos and videos of the entire roof. Pay extra attention to areas that might show signs of damage or wear, including as chimneys or skylights.
Step 5: Data Analysis and Report Generation
After the flight, the collected data is processed using the likes of Pix4D and other specialized software. This software helps stitch together photos to create a detailed visual map of the roof, which can be used to assess the condition of the roof and identify any issues. The final deliverables to the client typically include detailed reports, photos, videos, and sometimes 3D models.
