Roof Moisture FindIR™

Roof Maintenance in General

Waterproofing problems manifest themselves in two ways: Leakage and entrained moisture contamination. Leakage is pretty simple, although the leak inside the building rarely directly relates to the exact spot on the roof, since the water flows down the slope of the roof to a spot that is not sealed and into the building at that point. Most leaks occur where the waterproofing is sealed or where there is a penetration of the roof. Since most types of roof systems absorb some amount of water, it is harder to find the exact spot of water contamination in the insulation because it may not leak into the building until it has absorbed all the water it can hold.

There are three types of surveys that are used to find water in a roof. Nuclear gauges-which count neutrons, capacitance meters-which measure resistance, and infrared-which measures heat. Both nuclear gauges and capacitance meters are used to take spot readings on a 5’ X 5’, 10′ X 10′ or 20′ X 20′ grid on the roof. These measurements are used to extrapolate where the water is from the readings obtained from the gauges. These surveys are very labor-intensive and therefore expensive. They are good for types of roofs that do not gain or lose much solar energy and therefore, do not lend themselves to infrared.

Roof Infrared Basics

During the day, the sun radiates energy onto the roof and into the roof substrate, and then at night, the roof radiates the heat back into outer space. This is called radiational cooling. Areas of the roof that are of a higher mass (wet) retain this heat longer than that of the lower mass (dry) areas. Infrared imagers can detect this heat and “see” the warmer, higher mass areas, during the “window” of uneven heat dissipation.

Why Aerial Infrared

Performing infrared roof moisture surveys while standing on the roof is not the best method because imagery from a walk-on survey is not as useful as aerial imagery. The same laws of physics apply to both aerial IR and on-roof IR. A dry roof, low winds and no rain are needed on the night of the survey. However, the “window” when the roof is radiating heat differently from wet and dry areas is longer with aerial infrared because slight nuances of temperatures over large areas are recognizable. A high angle of view and high resolution are needed to produce usable imagery. We use large-format infrared cameras, which have at least 512 x 512 staring array detectors (262,144 pixels). From an altitude of 1,200 – 1,500 feet above the roof with over a quarter of a million pixels, the ground resolution element is about six inches square.

Visual photographs are taken earlier in the day or the next day. Both visual and infrared images are used to do the analysis by overlaying the AutoCAD drawing of the roof ‘over’ the digitized photographs and thermographs. The drawings are created indicating areas of suspected moisture contamination. The result is a report where visual, infrared and AutoCAD components (printed and video) are well matched and lined-up.

FIXED-WING AERIAL INFRARED IMAGING PROVIDES MANY ADVANTAGES OVER ON-ROOF INFRARED IMAGING:

  • Fixed-wing aerial infrared imaging provides many advantages over on-roof infrared imaging:
  • High-angle, straight down infrared images lessen reflection problems. High-resolution images capture large areas at once, making report writing easier and less expensive to produce.
  • Plan view allows for infrared images, visual images and AutoCAD drawings to be reconciled closely. As a result, the report is clear, concise and easy to understand
  • Plan view imaging allows accurate marking of areas of suspect roof moisture contamination.
  • The printed AutoCAD drawings can be used on the roof to paint areas of moisture contamination directly on the roof (after verification), if desired.
  • The trending of roof moisture becomes possible.

The biggest advantage of aerial infrared is on roofs that are the most difficult to image from any distance or angle. Roofs that, for instance, have a lot of ballast, are covered with reflective coatings or for whatever reason are impossible to image from the roof. With high-resolution, plan view aerial imagery, slight nuances of temperature can be seen from far enough away to actually see the pattern of heat and make a determination of where the problems are.


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Reference list of our clients whose names you will recognize

Abbott Labs
Anheuser-Busch
Bank of America
BE Aerospace
Bechtel Nevada
Becton Dickenson
BFI Waste Systems
Black & Decker
Borden Chemical
Bridgestone-Firestone
Brown & Williams Tobacco
Burlington Industries
Busch Entertainment
Cargill
CB Richard Ellis
CIBA Specialty Chemicals
Cisco Systems
ConAgra
Continental General Tire
Defense Information Agency
Defense Logistics Agency
Duke University
ER Squibb & Sons
EMC Corporation
Eveready Battery Company
Fleischmann's Yeast
Ford Motor Company
GAF Materials
Gates Rubber Company
Georgia-Pacific
Glaxo-Smith-Kline
Goodyear Tire Company
Harley-Davidson
Hatteras Yachts
Hilton Hotels
Hoechst Celanese Corporation
Hospital Corporation of America
International Paper
Johnson Controls
Inc.
Kelly-Springfield Tire Company
Kimco Realty
K-mart Corporation
Kohl’s
Konica Manufacturing
USA
Liebert Global Systems
Litton Poly-Scientific
Lockheed Martin
Louisiana-Pacific
Lowes Corporation
Lucent Technologies
Massachusetts Institute of Technology
MCI WorldCom
Michelin Tires
Mount Olive Pickle Company
NASA
NIST
Nortel Networks
Oxford Press
Parker Hannifin Powertrain
Perdue Farms
Pfizer
PYA Monarch
Quad Graphics
Raytheon Company
Sara Lee Corporation
SC Johnson
Sheraton Hotels
Smithfield Foods
Soil and Materials Engineers
Sumitomo Electric Lightwave
Coca-Cola Company
Trammel Crow Company
Trizec Properties
Tyson Foods
United States Postal Service
US Army
US Army Corp of Engineers
US EPA
US Foods
US Navy
Wachovia Bank
Walgreens
Wal-Mart Stores
Tremco Waterproofing Technologies
Xpedx
ZF Meritor LLC

Areas we service:

AK, AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY