has
nearly 13,000 taxicabs serving approximately 240 million
passengers every year. For decades, virtually all of these cabs
were Checker cabs. However, in 1982 the Checker cabs — along
with one very famous cab — were finally phased out of service.
What was the celebrated cab? A 1956 Cadillac that had been in
service since it was brand new.
As the car got older, the most common question
people asked the Cadillac cab owner was, “How do you keep it
running?” According to the owner, three words described the
secret to the car’s operating longevity: maintenance,
maintenance, maintenance.
The same holds true for a building’s roof. There
are steps facility managers can take that can add years of life
to a roof, which can prove to be a major cost savings as well.
It all comes down to maintenance, maintenance,
maintenance. Proper maintenance performed in a timely manner can
guard
against simple problems becoming major problems as they also
extend the life of the existing membrane.
The following are some common rooftop problems
that large and small facilities encounter and suggested ways to
handle them.
Rooftop Ponds: After a rainfall event or as ice
and snow melt, building engineers should inspect the roof to
make sure there are no “ponds” or “lakes” developing on the
roof. This happens when rainwater does not properly drain off
the roof, whether due to structural, design, or other problems
such as clogged drains.
Water allowed to build up on the roof will
adversely affect the roof’s membrane, especially the edge areas
of the roof. This problem intensifies if the “ponded water”
freezes and then thaws. As this happens, it can cause
considerable stress on the roof membrane as the ice expands and
then contracts. The most immediate way to handle this situation
is to drain the roof as thoroughly as possible.
Roof Foot Traffic: In some cities, especially in
older buildings, it is not uncommon for building occupants to
escape to the roof for some air and relaxation during office
breaks. However, this is rarely good for the roof.
Excessive roof foot traffic can damage the
membrane system, and often damage develops along edges and
standing areas where building occupants are most likely to
congregate.
Access to the roof should be restricted. Many
facilities now have a “roof log” so that managers know who was
on the roof, when, and for what reason. Some facilities have
been able to minimize foot traffic on
their
roofs and still offer occupants a rooftop getaway. This can be
accomplished by simply ‘beefing up’ the membrane in walkways, or
by installing a rooftop deck.
Rooftop Mechanicals: The condensation from air
conditioning and HVAC systems can produce a discharge with
normal use that can speed deterioration of the roof. Often, this
discharge is directed off the roof by a drainage system;
however, it is not uncommon for these pipes to become clogged,
allowing the discharge to blanket sections of the roof.
Complicating the problem, when these units are
cleaned and serviced, they are often cleaned using detergents
and chemical products that can prove harmful if they come in
contact with the roof membrane. To rectify this problem, HVAC
units and all rooftop mechanicals should be checked regularly to
assure proper drainage. Pipes should be checked for clogs, and
pans can be placed around the unit so that if a clog does
develop, the discharge will go into the pan and not on the roof.
