on
rooftops are often inviting locations for birds to roost. The
heat and shelter they provide are a draw for the birds. Also,
pools of water often collect on the tops of flat-topped
buildings, providing a convenient water source for the birds.
As their droppings accumulate and dry out,
though, this dust can get sucked into the HVAC system, spreading
the disease ridden dust throughout the entire building.
This can cause people to get sick.
Ornithological research has found more than 60 transmittable
bird-borne diseases and parasitic organisms that can lead to
illness or death. When dried-out bird droppings are disturbed, a
cloud of airborne dust can carry microorganisms into the lungs,
causing inhalation illnesses such as histoplasmosis. Eating or
drinking foods that have come into contact with
bird-related bacteria can also cause ingestion sicknesses,
including toxoplasmosis and query fever.
The current threat of avian flu means bird
control may become more of an issue for building owners. So far,
nearly all reported human cases of the illness have involved
contact with infected birds— butchering chickens, eating
undercooked poultry, or spending time in areas contaminated with
bird blood or droppings.
For 26 years, Frank Sorentino has managed the
outside structures and grounds of the Beaumont Hospital 106 acre
complex in Royal Oak, MI. Bird control is an ongoing project for
Sorentino and his crew.
“The pigeons go to the air handlers—the HVAC
vents on the rooftops,” says Sorentino. “When dried bird
droppings turn to dust and get sucked into the HVAC system,
you’re dealing with the potential for
spreading diseases throughout the hospital. It’s just not an
acceptable risk.”
The most effective and durable bird control
device for keeping birds and their droppings away from rooftop
HVAC systems, he’s found, is stainless steel “porcupine wire.”
These bird control strips are relatively inexpensive, easily
installed, and a quality stainless steel product can last
practically forever.
“We’ve used spikes around the HVAC ducts where
there are particular concentrations of birds, and it’s working
well,” said Sorentine. “We have a steady budget to add some each
year.”
The device dates back to 1950, when the first
“porcupine wire” was invented by Nixalite. Five years later,
these newly invented, spike-covered mechanical barriers were
installed on President Dwight D. Eisenhower’s farm
near
Gettysburg, PA. According to the farm’s maintenance supervisor,
Ken Kime, the original installation is still in place, and has
successfully kept the birds away without any maintenance for
more than 50 years.
Used for building ledges, parapets, roof ridges,
gutters, signs, awnings, HVAC units, rafters, or on most any
surface where birds can land, bird spikes are constructed of
stainless steel, plastic or a combination thereof.
According to Cory Gellerstedt of Nixalite, the
stainless steel models cost a bit more, but their longevity
evens out the expense over the product lifecycle. “Look for a
deterrent that will repel birds of all shapes and sizes. Some
products that are advertised only keep large birds away and are
only for light infestation problems because they have large gaps
between the wires, and small birds may be able to sit or nest in
between them. To avoid this situation, it is important to choose
a product that has 120 wire points per foot, with the spikes
pointing in all directions.”
“Some porcupine wire products are constructed of
all high quality stainless steel, some are made of plastic, and
others use a combination of the two. The stainless steel models
cost a bit more, but the longevity they provide is worth it.
Plastic can become brittle when cold and soft when it is hot,
and will eventually deteriorate from direct exposure to
sunlight.”
When installing bird spikes products make sure
you follow the manufacturer’s instructions very closely. Bird
spikes will only protect the area that they cover. A common
mistake is to run one row along the outer edge of a building
ledge, parapet or HVAC unit. If you do not cover the entire
surface, the birds will simply sit next to the spikes and may
push nesting materials into the spikes.
Another important consideration when selecting
bird spikes is the ease with which the product can be removed
for cleaning, painting, or other maintenance.
For example, some porcupine wire strips use a
mounting clip attached with fasteners or adhesives. The strips
slide into the clip for secure installation, but can also be
easily removed without damage to the spikes or the surface.
Glue clips work great for metal roofs and HVAC
surfaces that you may not want to penetrate with hardware. While
many manufacturers suggest gluing the spikes directly to the
surface requiring protection, Gellerstedt recommends using
adhesive installations with a glue clip only when the surface
cannot be penetrated with fasteners. Removing glued bird spikes
can be very labor-intensive and can damage the product, the
surface, or both.
Whether it is new construction or a retrofit,
successful bird control starts with a thorough cleaning of
installation surfaces. Any location serving as a site for bird
control must be disinfected, dried, and cleared of debris to
ensure not only a secure attachment, but also a reduced chance
of infection for workers.
Cleaning can have another advantage in that it
eliminates the scent trail; birds and animals are drawn to the
scent of their own waste. Thoroughly cleaning and deodorizing
installation surfaces eliminates this scent trail and
discourages pests from following it back to their old roosts.
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