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They say April showers bring
May flowers, but they may
also bring leaks if your roof
hasn’t been properly maintained and
inspected in the past year.
With the mild weather finally here,
now is the time to get someone up on
the roof to look for winter damage,
and identify any minor issues before
they become major problems.
“A roof inspection is the single
most important activity that an environmentally
conscious building manager
can do,” said David Hawn,
president of RCI Inc., an association
of consultants, architects, and engineers
who specialize in the design of
roofing. “Maintenance is the key to
realizing the full life cycle of a roofing
system – and that’s good for the environment. By detecting minor defects
and repairing them early, it is
possible to avert major problems in
the long run.”
A premature roof failure places a
heavy burden on the environment,
considering the energy costs for manufacturing
new roof materials and the
waste associated with the removal and
disposal of spent ones.
Many facilities managers are qualified
to perform roof inspections. A basic
survey for obvious damage is
better than no examination at all.
Damage often occurs near flashings,
wherever the roof meets a wall, or a
drain or other penetration.
“If you don’t get the full life out of
a roof then you are doing damage to
the environment,” said Hawn, adding that a professional, registered roof consultant
will not recommend replacing a
roof that hasn’t reached the end of its
service life.
“That’s where experience comes in. A
roof consultant can tell when a roof is still
good and when it should be replaced. He
will help the building owner eke out a few
more years of service life whenever possible,
which is especially appreciated in
difficult economic times.”
RCI recommends that roofs be inspected
twice a year, just after and before
winter. The advantage of inspecting a roof
in the spring is that maintenance and repair
work can be conveniently scheduled
over the summer.
Hawn said it’s important for inspectors
and managers to obtain accurate
technical information about the reliability
and performance of building products
and their suitability for a particular
application.
According to Walter Rossiter, technical
services director at RCI, the objective
of a roof maintenance program is to
extend the expected useful life (EUL) of
a roof system. The elements comprising
a successful program are periodic inspections,
routine maintenance and repair,
and correct application of quality
roofing products.
Many maintenance programs have
been developed to monitor the conditions
of roofing systems and schedule repairs.
Regardless of the age of the roof, regular
inspection and maintenance are vital to
ensure that a roof reaches or exceeds its
expected useful life. As a roof approaches
the end of its life cycle, maintenance
decisions become especially
critical.
A moderately experienced facility manager
can check the roof membrane, flashings
and drains for obvious problems. If
defects are spotted then it is time to call
in an independent roof consultant for an
objective evaluation of roof condition. In
this manner, serious problems can be
averted without concern that unnecessary
roof work is recommended.
Common Defects
Membrane defects vary according to
roof type. For a three- or four-ply builtup
roofing system, be on the lookout for
exposed felts, wind scour, blisters, asphalt
migration (down slope), ply slippage
(down slope), exposed embedded metal,
inadequately filled pitch pockets, splits or
tears.
Common defects in a two-ply modified
bitumen system include open seams, inadequate
bleedout, exposed bleedout, blisters,
fish mouths, wrinkles, exposed
reinforcing scrim, loss of granules, inadequately
filled pitch pockets, punctures,
tears or splits.
Single-ply roofs can have problems
with open-lap seams, short-lap seams,
fish mouths, wrinkles, inadequately filled
pitch pockets, punctures, tears or splits.
A standing-seam metal roof can have open seams at standing seams, missing or
backed-out fasteners, buckling of pans,
scratches, dents or corrosion.
Flashings are frequently found to be
a problem source. In general, the assessment
of flashings is similar to the assessment
of the membrane insofar as the
type and extent of defects. Two important
concerns not associated with membranes
are the vertical attachment and
the counterflashing.
When counterflashings appear damaged or flashings do not appear to be watertight
and performing well then plans should be
made to get them repaired.
The slope of the roof and drainage are
other important factors. Roof drainage
and roof deck slope are two distinctly
different parameters. As routine maintenance
goes, not much can be done about
the slope but something can be done
about the drainage.
An obviously clogged drain is a very
common problem in the spring and is easily
noticed and fixed by the building
maintenance staff. Just remove the debris
from the around the roof drain and then
from the roof. An independent roof consultant
can also assess the proper functioning
of the drainage system by noting
the roof slope to the drains and general
roof slope; and the size or amount of
drains, gutters and scuppers.
Drainage refers to the ability of the
system to carry water away from the
roof and the building. The building code
usually dictates the minimum level of
drainage required for a roof. Conventional
design calls for at least four drains
for larger roofs; a minimum of two
drains for roofs under 10,000 square feet, and a maximum spacing of 75 feet
in any direction for drains.
Other factors that are important to
note in a roof maintenance program are
the relative costs of repairs compared
to the cost of replacing the roof; the
leak history of the building; the durability
and toughness of existing membrane;
the type of attachment of the
membrane; the susceptibility to roof
traffic; and the importance factor,
meaning what is the use of the building
under the roof area.
A typical roof maintenance program
will score these various factors on a relative
scale of 1 to 10 based on the
knowledge and experience of the roof
consultant. The conditions of roofing
sections can then be ranked, prioritized
for maintenance or repair.
RCI’s Hawn said, most modern roof
membranes are rugged enough to withstand
the forces associated with winter
weather. Aside from actual structural
damage to the building from excessive
loads, snow and ice on the roof is not
usually the cause of damage to the roofing
membrane. However, severe winter
weather does contribute to the wear and tear on the roof.
“Water tends to remain on the roof
longer when there is snow and ice on the
roof because the water does not drain.
So a small defect that may not leak during
a typical rain event could leak when
snow and ice is on the roof,” said Hawn.
No matter the severity of the winter,
roof inspections should be conducted in
spring. If the building owner is having a
problem and does not have an in-house
expert, then the best move is to call a
roof consultant, who can provide an objective
and independent assessment.”
says Hawn.
“A registered roof consultant is not
going to recommend roof repairs or roof
replacements that are not needed.” ❑
William Myers is director of Communications
for RCI Inc., an international
association of professional consultants, architects,
and engineers who specialize in
the specification and design of roofing, waterproofing,
and exterior wall systems.
Founded in 1983 and based in Raleigh,
NC, RCI, Inc. regularly hosts educational
programs designed to demystify and explain
the application of building envelope
technologies. |
