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Re: GBlist: RE: Insulation/ attic- crawlspace
Insulation is only a problem if it migrates from where it is located
(inside building cavities such as walls and attics, and crawl spaces) to
where people are located (the living space). There are a variety of ways
that such migration takes place.
A low-tox insulation (such as AirKrete) can be quite costly, so I
usually recommend preventing the insulation from getting into the living
space. The thinking is this: if the insulation stays out of the living
space, you aren't exposed, so it can't affect you.
In new construction, you can build a very tight house (don't forget
mechanical ventilation), and the insulation, no matter what kind it is,
can't get into the living space. I've done this several times with
sensitive people with great success, even using insulation that would be
bothersome if a sensitive person is exposed directly.
In existing houses, you are limited as to how tight you can make a house
simply because you can't get to all the leakage points. Yes, you can
often tighten a great deal, but you just can't get an existing house as
tight as one you are building from scratch and tightening as you put it
together.
My suggestion in your situation is this: use a fan to blow air from the
outdoors into the living space to pressurize the house. That way, air
will enter the living space via the fan, then it will leak out through
the structure, through building cavities, and toward the outdoors. Thus
there will be no air (or pollutants) traveling from the
insulation-filled cavities into the living space, the air will be moving
in the opposite direction. Please be advised that I would not make this
same recommendation in a cold climate. You said you lived in a warm,
moist climate. Pressurization in a cold climate can lead to hidden
moisture problems. For more information see my book Understanding
Ventilation.
Having said all that, in the majority of cases, sensitive people are
bothered by materials that are actually within the living space. Things
such as carpet, cabinets, wall paneling, furnishings, cleaning products,
etc., are more often the problem than someting going on in a building
cavity.
--
John Bower, The Healthy House Institute
http://www.hhinst.com/ email: healthy@bloomington.in.us
430 N. Sewell Road, Bloomington, IN 47408
Phone/fax 812-332-5073
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