Checking Your Home For Deteriorating Asbestos
Materials:
Asbestos shows up all over the house. It could
be part of the insulation in your attic or
exterior walls. It may also be contained in
acoustic ceilings or floor tiles. In older homes
it often is found on furnaces and boilers and
the ducts and pipes of heating systems.
Medical researchers have reported that exposure
to asbestos can cause several forms of lung
cancer possibly 40 years or longer after the
initial exposure even to relatively small
airborne amounts. Another lung disease,
asbestosis, generally is thought to affect only
asbestos workers, but even casual exposure to
asbestos particles found in some building
materials and home improvement products is
thought to be potentially dangerous to
do-it-yourselfers.
In the home, the health hazards can increase if
asbestos containing materials (ACM) become
friable (easily crumbled or crushed into powder)
as a result of water damage, for example. When
this happens, the materials can release tiny
asbestos particles into the air where they can
be inhaled; once the fibers enter the lungs they
stay there permanently. NOTE: Although it is
unlikely that everyone ever exposed to asbestos
will get an asbestos linked disease,
statistically the risk is considered higher than
for those who have never been exposed.
Problems can be caused by some acoustic tiled
ceilings, for example, if leaking water causes
them to deteriorate. Similarly, asbestos dust
can be blown though your home when repairs are
done to the heating systems or to surrounding
areas. The dust particles and fibers are so
small they can remain airborne for long periods;
unfortunately, furnace filters and vacuum
cleaners cannot filter them out of the air.
Remember that it takes a laboratory test to
determine if a product contains asbestos. While
some experienced contractors and home inspectors
will make educated guesses, if tests aren't
made, it's best to treat suspected materials
such as the wrapping around heating pipes and
heating and air conditioning ducts as if they
contain asbestos.
Some older furnaces (hot air systems) and most
older boilers (hot water systems) are wrapped
with asbestos. The packing around boilers and
furnaces looks like a soft plaster, while the
wrapping around heating pipes looks like whitish
cardboard tubes strapped around the pipes.
Sometimes the pipe wrapping is covered with a
cloth and this may be labeled as an asbestos
product. Wrapping on hotair ducts is usually
very thin (about as thick as a dozen sheets of
writing paper).
Examine the heating equipment packing to see if
its surface is smooth. Past or present leaks
dripping onto it will mottle it and cause it to
become friable. Examine the pipe wrapping and
look for loose ends or pieces that have fallen
off the pipes. WARNING: Old crawl spaces often
have damaged pipe lagging or wrapping, and if
there is an expectation of workmen using the
space during repairs or construction, their
health and safety must be considered.
Many experts suggest that the best things to do
with asbestos when it is found in the home is to
leave it alone unless it has been torn or
damaged. Removal of the asbestos material often
does more harm than good, because many fibers
are released into the air during removal. If
duct wrap or pipe wrap is damaged, it can be
"encapsulated." This means wrapping it up with
foil faced fiberglass insulation or other
material. The insulation is taped together and
this covering ends any threat of airborne
particles. This is the cheapest, most practical
thing to do.
Damaged asbestos packing around boilers and
furnaces should be repaired or sealed over by
professional heating contractors. Make sure any
contractor who replaces an old boiler or furnace
takes proper precautions to protect the health
of his workmen and your family. The area should
be sealed off with plastic, the material misted
with a sprayer and everything mopped up. This is
done twice. The workmen must wear protective
clothing and respirators.
Most of the 9 and 12inch square floor tiles (and
even the backings of some vinyl sheet goods)
that are installed in houses contain asbestos.
Those in basements are usually asbestos cement
(AC) tiles, while those above are usually vinyl
asbestos tiles (VAT). The experts suggest that
there is no cause for alarm with these tiles
except under two conditions: Floor tiles that
experience an enormous amount of foot traffic
may have their surfaces worn through and
contribute fibers to the air. Floor tiles that
are ground up or damaged with renovation efforts
should be considered hazardous. Do not remove
floor tiles with a floor sander. With
remodeling, consideration is usually given to
installing new flooring materials over top of
any asbestos bearing products.
Some sprayed-on or troweled-on ceilings and some
ceiling tiles may contain asbestos. If there is
damage to the ceiling or if you plan remodeling
that might include removal of ceiling materials,
remove a small piece (be sure to wear a
respirator mask) and place it in a coffee can
before taking it to a lab for analysis (look in
the Yellow Pages under the "laboratories
testing" heading.) If it proves to be asbestos,
consider drywalling over the ceiling or hiring
professionals to remove it.
All workmen should be advised that they must
wear protective clothing and a respirator.
Some wall and attic insulation installed between
1930 and 1950 contained asbestos. If renovation
is contemplated that will disturb asbestos
insulation, have the work done by an experienced
contractor.
A crude form of encapsulation can be
accomplished by lightly placing blankets of
fiberglass insulation over the existing
materials. NOTE: Do not use fiberglass blankets
with any backing on them as this places a vapor
barrier between the layers of insulation.
Other insulations can be blown in, but the
potential for disturbance should be considered.
If the attic is to be used for storage, consider
installing perpendicular joists across the
existing ones. This would provide plenty of
space for extra insulation and would be easy to
floor over. Beware of attics containing asbestos
and unsealed return ducts for heating systems.
Duct seams should be sealed with special
cements.
Asbestos cement shingles have been used for
roofing and siding. They look like rectangular
rigid pieces of corduroy. These are apparently
no problem, but if the roofing or siding is
being replaced, caution your contractor to have
his men wear protective clothing and respirators
and be sure it is disposed of properly.
Removing asbestos from a home is not a job for
amateurs, it is work for an experienced
contractor (but be aware that while expert
removal is available, it is often difficult and
expensive to contract). Many jurisdictions
tightly regulate disposal of these materials and
hence this can be expensive as well.