Asbestos
Asbestos is a mineral that has excellent binding qualities. It is a
long-lasting, dependable material that is not soluble in water and has
been used successfully in building products and components, and
insulations for many decades.
In the 1960’s concerns surfaced about asbestos and its relationship
to some cancers. Workers in some industries as well as miners were
developing cancers caused by asbestos in the air they were breathing.
These cancers affect the lungs and respiratory system. Public
awareness evolved from testing in public and commercial buildings,
schools and hospitals to testing in homes.
Once it was determined that asbestos could have a negative impact
on the health of people who are exposed, the production of asbestos
was banned for use as building materials, insulation, etc. Production
of asbestos ceased in 1973 and its installation was banned after 1978.
Typical uses and locations found in homes are:
- Insulation: Rockwood insulation is found mostly in attics and
sometimes in walls. Ovens, ranges, toasters, dishwashers, heating
pipes, ducts, boilers and furnaces would typically have insulations
which contain asbestos during the years from about 1910-1975.
- Building materials: Asbestos in cement siding and roofing were
very common in the 1940s and 1950s. Transite ductwork was used below
concrete floor slabs, as chimney flues and as 1/4" thick sheets for
fire protection. Vinyl: Asbestos floor tiles were the tiles of
choice form 1930 to 1970. Ceiling tiles and some spray-on textured
or popcorn ceilings have ACMs. It is not likely that you will find
asbestos in a home that was built after 1978
The main concern with the ACM is its condition. If the material is
friable, which means the asbestos fibers can become airborne, it
should be mitigated. Mitigation occurs in two forms: removal and
encapsulation. Removal is almost always the preferred solution because
it is unknown how long the encapsulation will last and the release of
fibers will re-occur.
If a home inspector suspects that friable asbestos is present in a
crawl space or basement, the inspector might not enter the space for
fear of contamination.
The presence and type of ACM can only be determined by analysis
under a microscope. It cannot be determined visually.
The mitigation process is very specific and the cost is not much
higher for removal than it is for encapsulation.
Removal requires the following;
- Prepare the area with positive airflow to the exterior to
capture and discharge airborne particles to the exterior. Small
asbestos particles can remain airborne for days in still air.
- Wet down the ACM as well as adjacent areas of concern, such as
the floor.
- Isolate the areas and the ACM. This is typically accomplished by
building a plastic tent around part of of the subject area. The tent
is moved to isolate other areas with ACM as needed.
- A proper respirator should be worn to capture the smaller ACM
particles. Goggles and disposable coveralls should also be worn.
- Removed ACM is captured in bags, transported in trucks designed
for this use, and disposed of at designated hazardous waste
locations.
- The mitigator removes coveralls and then showers in a plastic
tent in the mitigation area.
- Air testing is performed after removal and clean-ups to
determine if there are asbestos particles in the air.
The cost for removal is specific to the contractor. However,
removal in a residential situation can be typically accomplished for
$2000 to $5000.
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