Common Signs That Roof
Replacement is Necessary:
Although all roof membranes have
different physical properties and failure modes there are certain deficiencies
that are common to all roof membranes. Here are some common failure modes in
all roof membranes to look out for:
1.
Brittleness: All roof membranes become brittle at the
end of their service life. This phenomenon is more rapid in some membranes.
Once the material becomes brittle it losses the elasticity required to provide
weatherproofing service. The material can be tested (tensile/elongation tests)
to determine remaining service life or failure can be illustrated through
grazing/cracks and splits in the membrane surface. Visual observation of
material scrim or reinforcement is also an indication of material failure.
2.
Wet Insulation: All roof insulations lose structural
and thermal integrity once they are wet. All wet insulation should be removed
from the system to avoid costly structural deck damage (particularly on metal
decks). Typically, if more than 25% of a roof system has wet insulation a full
roof replacement is recommended. Wet insulation can be determined by any method
of moisture testing. If non-destructive moisture testing is conducted Gravimetric
Testing should be conducted to verify that the material is wet. Some adhered
membranes will illustrate wet insulation through excessive blistering and
membrane ridging.
3.
Flashings/Penetrations: Flashings and penetrations are
the most vulnerable point of a roof system and nearly two-thirds of all roof
leaks occur at these points. Openings, splits and sagging of flashings
materials are common causes of roof leaks. Excessive openings or displacement
of these materials can lead to free flow of moisture infiltration into the
system and the building.
Paragon has developed a specific material testing program
that can identify the remaining service life of an existing membrane; Forensic Analytical Serviceability Tracker
(FAST)
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