Technology
The Importance of Roof Moisture Surveys
Moisture located within a roofing system reduces thermal efficiency, thereby
increasing heating and cooling costs and contributes to the deterioration of the
roof membrane and roof deck.
Properly utilized in a timely manner, a moisture survey can locate the source of a roof leak
and the extent of moisture within the roofing system before substantial interior
damage results. It should be an integral part of any roof management program, as
it provides a true picture of a roof systems current condition.
It is invaluable in establishing a preventive maintenance program, as well as a
useful diagnostic tool to review the condition of an existing roof prior to the
expiration of a warranty, or a new roof application prior to final acceptance.
A roof moisture survey will also aide in establishing the extent and nature of
required roofing work and as such is an effective budgetary tool.
Roof moisture surveys can be conducted with both destructive and nondestructive
testing.
Nondestructive Testing
N. American Roof Management Services is capable and qualified to provide nondestructive testing utilizing either infrared thermography or capacitance based technologies which can be used separately or in tandem.Infrared thermography does not actually detect moisture but rather uses an infrared camera operated at night to detect heat loss in a roof system. Through daytime solar gain, insulated roof systems containing either wet or dry insulation absorb heat. However, due to its greater thermal mass, areas of roof containing moisture laden insulation take much longer to cool versus areas containing dry insulation. It is this difference in emitted thermal radiation which can be detected by the infrared camera.
Capacitance technology emits electronic signals and directs them towards the roof surface. When conducted over a roof system containing both dry insulation and roofing felts, no readings are registered as the low frequency electronic signals are insulated from each other. However, the presence of moisture will complete an electronic circuit and generate readings that increase with the extent of roof system moisture content.
A variety of factors can cause some inaccuracies in nondestructive testing. For this reason, physical confirmation through destructive testing is recommended.
Destructive Testing
Consisting of the physical cutting into the roof system, this type of testing may be conducted to not only verify the presence of moisture, but also to determine roof system composition and individual component condition of both existing roofs and new roof applications.Cut tests most often involve coring the entire roof system. Cored roof system samples can be analyzed in a number of ways including but not limited to moisture content, bitumen content, bitumen type, bitumen condition and tensile strength.
A moisture probe using an electrical test meter is a less intrusive destructive test and is effective in confirming moisture content within a roof system.