| Q1)
Why not just walk onto the roof to perform an infrared roof moisture
survey? |
A1. Why not just fly over it and perform the
survey? No site access problems, no ladders required, no image perspective
problems, no trouble moving about the roof levels or other obstacles... |
| Q2) What type of roofs
do not lend themselves to aerial infrared inspection? |
A2. Standing-seam metal roofs do not lend themselves
to aerial IR inspection. Other flat or low-slope roofs that have highly
reflective coatings sometimes pose difficulties. |
| Q3) Do aerial infrared
surveys have to take place at night? Why? |
A3. No, they don’t have to, but the conditions
are generally better and more reliable because the major source of distraction
(the Sun) is absent. Also, air traffic is lower, as are wind speeds and
turbulence levels. |
| Q4) Can aerial infrared
surveys be used for leak detection? Why or why not? |
A4. An Aerial IR survey will greatly assist
the leak detection process, but is not leak detection, per-se. We have
found that roof leaks are almost exclusively found within the area of
water contamination of the roof insulation, which is what our surveys
do detect. If roof maintenance personnel conduct a detailed inspection
of the indicated water contamination area from the
aerial survey, they nearly always locate the leak source. However, there
are some leaks that occur from having the water pass directly down through
the roof flashing, for instance, at a cracked or ill-fitting skylight,
etc. |
| Q5) What special equipment
is required for aerial infrared survey? |
A5. A very reliable aircraft, a high-resolution
infrared camera with appropriate mount and the best digital recording
equipment available. Having a high-resolution camera with 512x512 focal
plane array detector (262,000 pixels), with a low-resolution recording
medium defeats the purpose of retaining all the detail necessary to conduct
a good analysis of the roof problems. A computerized moving map with Global
Positioning System (GPS) input is highly desired in order to quickly and
accurately locate the many building roof targets that comprise an aerial
IR survey mission. This is not equipment but a highly skilled pilot is
needed to fly low, slow and in the middle of the night. |
| Q6) How do weather conditions
affect an aerial infrared survey? |
A6. The same weather conditions that positively
or negatively affect a walk-on inspection apply to aerial surveys. We
look for a calm, clear night after a day with good solar radiation levels.
We can accept less than perfect conditions because the camera we use is
so capable. Any time of year will work, as long as there is little rain
water, snow or ice on the roof surface. |
| Q7) Is a baseline required
to generate a positive result? |
A7. No. Even if a report from a walk-on inspection
or a previous aerial survey is available, it may be out of date or of
poor quality. We ask for and gratefully accept any and all information
available concerning the roof, including: roof type, age and materials
of roof construction, known leaks or leak areas and previous visual, IR
and other technical inspection results. |
| Q8) How does Stockton
Infrared use CAD drawing to support customers of aerial infrared surveys? |
A8. In our opinion, CAD drawings are the ultimate
form of data that we can provide to the customer for his direct use in
quantifying the roof problems and locating the areas that need further
visual inspection and repair. These drawings, when verified, create a
great bid document for hiring a roofing company to repair damaged areas
of the roof(s). |
| Q9) How often do you
recommend a aerial infrared survey be conducted on a roof? |
A9a. As an integral part of an overall roof
asset management program, we recommend all new roofs receive an initial
inspection to insure they were not closed up wet and a follow-up inspection
after approximately six months to make certain that the roof was properly
installed. This timing regime will help the building owners with acceptance,
bond, warranty and insurance issues.
A9b. Owners, operators and tenants of existing buildings can benefit from
aerial IR surveys of their roofs every couple of years. Once the faults
that were discovered in an initial aerial survey are repaired, follow-up
surveys will discover new problems when they are quite small and relatively
inexpensive to repair. This regime of inspections has repeatedly shown
substantial savings in roof maintenance costs over the life of the roof,
as well as helping to as much as double the service life of the average
industrial flat or low-slope roof. |
| Q10) Are there any other
points that you think people would like to know about aerial infrared
roof moisture surveys? |
A10a. Aerial IR surveys are fast, efficient,
effective and safe. For single building roofs over 100,000 square feet,
the cost is comparable, or less expensive, than a walk-on survey and the
results are superior. For multiple smaller buildings in a city or county
area, an aerial survey can be completed in one night in a fraction of
the time it takes a ground-based team. We have quite a lot experience
with walking roofs, since that was the method we used until 1996.
A10b. Perhaps the biggest advantage of aerial infrared is not its use
on roofs that have well-defined areas of moisture at all, but those roofs
that are the most difficult to image from any distance or angle. I am
referring to the roofs that, for instance, have a lot of ballast, are
covered with reflective coatings or ones that for whatever reason are
impossible to image from the roof. With high-resolution aerial imagery,
slight nuances of temperature can be seen from far enough away to actually
see the pattern of heat!
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