| Infrared Flat Roof Moisture Survey Long Wave Imager | Infrared Flat Roof Moisture Survey Short Wave Imager | Nuclear Flat Roof Moisture Survey | Capacitance Flat Roof Moisture Survey | |
| PROPERTY SENSED | Temperature differential | Temperature differential | Relative quantity of Hydrogen | Relative current flow |
| VERIFICATION | Invasive necessary | Invasive necessary | Invasive necessary | Invasive necessary |
| COVERAGE AREA | 100% | 100% | varies depending upon grid size, normally 1% – 4% | varies depending upon grid size, normally 1% – 4% |
| ROOF MEMBRANE TYPE | ||||
| Built-up – smooth | Yes | Yes | Yes | Yes |
| Built-up – aggregate | Yes | Yes | Yes | Yes |
| Modified Bitumen – smooth | Yes | Yes | Yes | Yes |
| Modified Bitumen – aggregate | Yes | Yes | Yes | Yes |
| Single-ply – smooth | No | Yes | Yes | Yes, EXCEPT butyl rubber or EPDM |
| Single-ply – ballast | No | No | Yes, requires preparation | Yes, EXCEPT butyl rubber or EPDM |
| Spray Applied Foam (SPUF) | No | Yes | Yes, requires preparation | Limited |
| REQUIRED ROOF CONDITIONS | ||||
| Roof Surface | Dry, free of standing water, ice or snow | Dry, free of standing water, ice or snow | Dry, free of standing water, ice or snow | Dry, free of standing water, ice or snow |
| Weather | Sunny, no precipitation day or evening of the Survey | Sunny, no precipitation day or evening of the Survey | No precipitation the Survey (protect the gauge) | No precipitation the Survey (protect the gauge) |
| Winds | <15 mph | <15 mph | within safe range for personnel | within safe range for personnel |
| Temperature | Daytime highs above 40°F | Daytime highs above 40°F | within safe range for personnel | within safe range for personnel |
| Time of Day | Post Sunset | Post Sunset | Daytime | Daytime |
| APPLICABLE STANDARDS | ASTM, Infraspection Institute | ASTM, Infraspection Institute | ASTM | ASTM |
| LIMITATIONS | Not recommended for ballasted or reflective roof surfaces | Not recommended for ballasted roofs | Collects data from a very small percentage of the roof, can be labor intensive | Collects data from a very small percentage of the roof, false positive or negative results possible |
| BENEFITS | 100% of roof covered, usually most cost efficient | 100% of roof covered, usually most cost efficient | Best for ballasted roofs, less weather restrictions | Less weather restrictions |
For a printable pdf copy of the Comparison of Common Flat Roof Moisture Tests please click here.
