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.