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Fiberglass, Mineral Wool &
Home
Insulation
Fiberglass – loose-fill, or in the
form of rolled blankets and batts – is by far the most common
type of home insulation material. Fiberglass is made from molten
glass, and is usually presented in yellow or pink.
Mineral wool (rock wool and slag wool) is manufactured
similarly to fiberglass, with molten rock instead of glass, and
also comes in batts or rolled blankets, or loose-fill. This
material is more common in Europe, Australia, Canada and New
Zealand than in the U.S. and it's a good alternative to
fiberglass.
See also: Cellulose insulation
The uses of fiberglass and mineral wool
The uses of fiberglass and mineral wool in home insulation are
the same.
Loose-fill
Fiberglass and loose-fill mineral wool are used in…
- unfinished attic floors;
- enclosed existing walls (or open new) wall cavities;
- home hard-to-reach places.
Loose fill fiberglass and loose-fill mineral wool are
particularly adequate for adding insulation to existing home
areas, or around obstructions and irregularly shaped areas.
Batts and rolls (blankets)
Fiberglass and mineral wool blankets are commonly used in
foundation and unfinished walls, ceilings and floors. They are
installed between studs, joist and beams, specially when they
involve standard spacing and are free from messy obstructions.
Installation
Fiberglass and mineral wool blankets installation can be a do-it-yourself job, contrarily to loose-fill installation.
Loose-fill fiberglass and mineral installation demand special
equipment to be blown into place, and some knowing about
thickness and application…
Be carefull with batt installation: the R-value of the
insulation is often significantly lower than that that is was
supposed to be due to common deficient installation. If the batt
aren't well fitted with the surrounding structures, the loss of
efficiency will be greatly diminished.
Performance and Prices
Rockwool performance is higher than that of common fiberglass:
approximately R-3.7 per inch, which amounts to high-density
fiberglass batts or cellulose R-values.
Mineral wool has a higher density, and can provide better
acoustical and insulating performance than fiberglass. Besides,
mineral wool doesn’t lose its insulating value when wet and has
an outstanding resistance to fire.
However, since mineral wool is a less common material, its
prices are often higher than those of fiberglass (prices for
mineral wool blankets may vary considerably).
Installers are also less familiar with mineral wool than with
fiberglass insulation, and that may also be an advantage
of fiberglass.
In the whole, final costs and global performance of installed
fiberglass and mineral wool aren’t very different.
Safety
Mineral wool is a particular safe material. Several studies demonstrate that there
isn’t any association between lung cancer/respiratory diseases
with exposure to rock and slag wool.
Some health experts claim that fiberglass fibers,
when inhaled, are carcinogenic. But institutions as the
American Lung Association
state that fiberglass insulation “is safe, when it is properly
installed”. The very fact that fiberglass is in use as a home
insulation material since
the 1930 without reported health problems,
supports this last position.
Be careful, anyway. Direct contact with fiberglass materials (or
exposure to airborne fiberglass dust) may indeed irritate the
skin, eyes, nose and throat, cause itching, and ultimately can
be cause of lung cancer: installation should be properly done,
to avoid unwanted exposure; fiberglass insulation packages
display cancer warning labels in many countries (they are
required by the U.S. Occupational Safety and Health
Administration (OSHA),
the International Agency for Research on Cancer (IARC)
and the National Toxicology Program (NTP)).
See also:
Roof and Ceiling Insulation
Attic insulation
Pipe insulation
Insulation
basics
Insulation
materials
Sprayed foams insulation
Cellulose insulation
Reflective insulation: Radiant
barriers
Insulation
performance
Walls Insulation
Moisture and
insulation
How to deal with
Insulation contractors and home builders
Insulation in
your climate zone
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Fiberglass
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