Asbestos
is a naturally occurring substance, which was widely used because
of its ability to withstand high heat loads without burning or breaking
down. Unfortunately, it was discovered that over time it breaks
down into small fibers that when ingested become lodged in the lungs
where it builds up and destroys the tissue and can cause serious
health problems including Mesothelioma which is a cancer of the
chest and abdominal membranes caused by the inhalation of asbestos
and Asbestosis, a chronic disease of the lung which makes breathing
progressively more difficult. These diseases can lead to death but
because it has a latency period of twenty to forty years, it takes
a while for manifestation of the symptoms. In 1971 asbestos was
listed as an EPA hazardous air pollutant, but because its use in
the past was widespread it is still possible to find it in a variety
of places in both residential and commercial applications. Asbestos
should only be considered a problem if it is breaking down or falling
apart, allowing its' fibers to become airborne. Removal or encapsulation
(sealing the asbestos, normally beneath a wrapping of epoxy) should
only be conducted by a licensed contractor trained to handle the
remediation of it. If asbestos is found and is in good condition,
care should be taken not to disturb it or damage it. Below, is a
list of common places where asbestos can be found. If in doubt,
a sample of the suspected material can be collected by a professional
testing company and tested for its' content.
Hot Water and Steam Pipes
Between 1920 and 1972, asbestos was pre-formed
in half rounds then wet-gauzed in place around pipes. Pipes were
also wrapped in asbestos paper tape. If a whitish material is around
the pipes (usually in the basement) it may be asbestos. Test, monitor
and take further steps as necessary.
Ducts and Furnaces
In the 1940's and 1950's ducts and furnaces
were insulated with asbestos impregnated papers. Chalk colored insulation
was applied as flat sheets as thin as 1 / 16" or as a corrugated
version. If the asbestos breaks down it can be released into the
ventilation system. Asbestos cement was a heavily used material
for heating ducts built into concrete slab floors in houses built
in the 1950's through the late 1970's. Inspection of these is highly
recommended.
Boiler wraps
Usually made of chalky blocks approximately
2" thick, they were fastened to boilers by wires or metal straps
and then coated with plaster-saturated canvas. High humidity or
water can cause it to breakdown and disintegrate quickly. They were
in use up to 1975.
Insulation
Asbestos can be found in wall, ceiling,
and attic insulation constructed between 1930 through 1950. Usually
found inside of the house sandwiched between the framing and the
plaster walls. If this is found, professionals should be called
for any remodeling or renovations.
Roofing and Siding
From the 1940's through the 1960's, asbestos
cement was commonly used for roofing shingles. The shingles are
usually gray and can bear brownish-white streaks where water drains
more slowly. They will make a dinging sound when hit with an object.
Between the 1930's and the 1970's asbestos-cement shingle siding
was also used. They can be any color and they have a propensity
to crack and chip along their edges. Although general use was discontinued,
it is sometimes still being used. If the shingles are breaking apart,
care should be taken that the fibers do not enter the house through
open windows and doors.
Joint Compound and Textured Paint
Until 1977, joint compound used to tape
joints in wallboard and fill holes in plaster contained up to fifteen
percent asbestos. Textured paints before 1978 may also contain asbestos.
Do not disturb if it is in good condition. In 1977, the Consumer
Product Safety Commission banned patching products containing asbestos
because of their health risks.
Fireproof Board
Still being manufactured, these boards
are 1 / 4 to 3 / 4" sheets, gray in color, almost resembling
plasterboard. It can be found around wood burning stoves, oil, coal
or wood furnaces to protect the floors and walls around them. It
may be brittle so care should be taken around it.
Asbestos Ceiling Tiles
Usually a brownish material, it can be
found in acoustic tiles that are often seen in recreation rooms.
Even today they are being made so ask the manufacturer if there
are any doubts. But as long as they are in good condition there
should be no worries.
If further information regarding asbestos
is needed, it may be obtained from the Environmental Protection
Agencies Asbestos hotline at 202.554.1404.
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