Polyurethane foam is not what I would call green. It off gases, most contain Penta or Deca BDE's as fire retardants,( which are banned in Europe) and urethane foam burns and the smoke is toxic. HMM..why would you want to put that in your home, just because the R-value is a bit better. Not me. Check the MSDS sheets on all these products, they all contain some pretty nasty chemicals. One product that you won't likely be able to find an MSDS sheet online is Retrofoam, I have one from the US Dept of Labour,and guess what it shows formeldahyde as an ingredient. I have researched this alot. The only true green foam insulation on the market right now is Airkrete. MSDS sheet is available, and its all inorganic, no off gassing and no formelahyde or other nasty chemicals as in the other stuff.

In addition to saving energy, "green" means being both healthy to humans and the environment. Someday taking care of personal health and environmental health will be understood as one and the same. I think most Mother Earth News readers understand this already. You have to be careful of eurethanes and plastics as they may off-gas pthalates and other chemicals which are very disruptive to the human hormone systems especially for males. Are they biodegradeable? If they are not biodegradeable then are they recyclable? Our homes won't be around forever and we shouldn't be leaving expensive toxic disasters for future generations to clean up. There is an company here in Michigan called Retrofoam that claims their product is nontoxic and produces no offgassing or fumes. It looks impressive. I am considering their product for my walls and I believe it would be a good option for an old house with lots of gaps and crevices.

I have a followup to the attic insulation job I completed last winter using the formaldehyde free fiberglass. Now that it is summer I have to say I am experiencing the most noticeable differences. The house remains very cool throughout the day that I do not need to use my airconditioner much anymore. The 12000 btu window A/C I have is too large and cools the 1750sq ft on slab house too rapidly. One might think that is great, however, it doesn't have time to remove the humidity! As a side note using a window AC and a box fan to circulate the air seems to be far more efficient than what people pay for central a/c. I have to get a smaller one that removes the humidity better. I am actually looking forward to the 90 degree days just so I can dry things up.

I have built and designed many homes..see
www.heiningerbuildingdesign.com, Recently, I have been
building-hands on a small house for myself with the ARXX system...
one of the foam block concrete block systems R-50, and then in
framed areas installed sheets which I ordered to my
specifictions...size and thickness. Foam may not be green, but the
resulting house certainly is..See unfinished pictures at the end of
Design 4 of the website. Very tight, incredibly strong, no
vibration when the wind blows sixty. A great building system, as
long as the design does not get too complicated. Also for more
check out my blog www.savethehoney.blogspot.com

Closed cell spray polyurethane foam is revolutioniving the way
homes and attics are insulated. Closed cell foam has the highest
r-values, is an air barrier and a vapor retarder. Condensation
comes from warm-moist air "reaching" a cool surface. If the
moisture laden air can not reach the cool surface, condensation
will not form. Ventilation is required in homes that are insulated
with closed cell spray foam because the envelope of the house will
be tighter that a typical house and not have the energy zapping air
leaks.

I have seen alot of info about using spray polyurethane in walls
and under flooring, but is this material also suitable for attics?
I seem to find conflicting information about condensation etc?
Thanks

get off ur lazy buts and straw bale it!

What is "Green" insulation? Insulation, by definition, is a
energy saving product and intrinsically "green". There are
insulations that have higher recycled content but don't insulate
well and there are insulations that are petro based and are
superior insulators. I have to think that the first step is to
insulate correctly and with the most energy saving material. Hands
down that product is a EPA approved closed cell polyurethane foam
insulation. This product has the highest R-value, air and vapor
barrier qualifications and is always a custom fit. I have to
disagree that water blown open celled polyurethane foam is the
"greenest". The R-values are no better than any other fiberous
material because they all use air as the insulator. Plus, the water
blown polyurethane foam produces wasted material. This is the ONLY
insulation that I have ever seen that has excess that can not be
reused.

I have a 2-story (plus semi-finished attic) c. 1900 victorian
that sits up on brick pillars with a crawlspace underneath. The
first floor wood floors are freezing cold in the winter. Would the
formaldehyde free white insulation be the best choice?

Well I have just completed insulating my attic after a two year
period of researching and heming and hawing. Here is the bottom
line of what I have found. Sheep wool: The greenest insulation
without a doubt is sheep wool insulation. It is not subject to
pests as it is treated with the natural boron. It is naturally
flame retardant and has been used for centuries as hearth rugs to
prevent cinders from burning flooring. It also keeps its R value
when wet. It is very luxurious stuff and without a doubt will give
you the warmest house. However it is expensive about 4 times the
cost of fiberglass. I wish I could have afforded to use it. Blown
in cellulose. It sounds like a good idea but there is a problem
with it. It causes a lot of dust in the homes of people who have
used it. Having to be blown in it can create quite a mess in the
attic. What if you have any new wiring or cabling projects in the
future? How are you going to wade through all that mess? It may be
a good idea if it is sprayed in wet into wall cavities as that way
it can fill up cramped spaces and will stay put. It costs a little
less than the generic pink fiberglass. Recycled denim: This would
be good if it was easy to obtain. It is also one of the more
expensive options. Not as expensive as wool but about half as so.
The insulation I went with: I ended up going with Formaldehyde free
fiberglass insulation. Aka the white stuff. Here were my reasons.
1. It has no formaldehyde so it is not toxic. 2. It is made of long
strand fibers and so is bonded very tightly, is far more resilient
than the pink crap and is much less likely to release fiber
particles into the air. It was very easy to handle and doesn't
collapse like the pink stuff. In fact it was very tightly packed
and when opened it expanded rapidly and volumnously. Although, I
still used gloves even though it was soft to the touch compared to
the formaldehyde stuff. 3. It was made from 25% post consumer
recycled glass.

Actually, water-blown, polyurethane spray foam insulation, in my
opinion, is the "greenest" insulation. It is FAR SUPERIOR than
cellulose or any of the other insulations on the market. It reduces
your energy costs by up to 50%, and does not contain any
ozone-depleting chemicals/gasses.