[Greenbuilding] Bio-Based Foam Insulation

[Keith Winston]

I've never seen a DIY for bio-based. People I've worked with have had it 
installed by contractors on several projects, it works very similar to 
standard polyurethane spray foam. It requires a big expensive 
proportioner etc etc, so it's not really a DIY kind of thing. I'm sure 
others have more direct experience with it.

Oh, just to be clear: bio-based IS a polyurethane foam, like most other 
spray foams, and (like many) can be found in open and closed-cell 
versions, at various densities and expansion rates (maybe not BioBased 
tm, but other soy or bio-enhanced foams). As another example, Icynene is 
an open-cell polyisocyanurate, I believe, which is chemically very 
similar to a polyurethane. All of them are mostly petroleum products. 
The bio-based can substitute 10-30% of the materials with soy or other 
vegetable oil-based materials. Interestingly, in the MSDS I see, the 
sole ingredient of Biobased is listed as Polyurethane foam, I guess they 
don't want to give away any trade secrets.

There are a number of companies that have 1 or 2-part polyurethane DIY 
kits that have 10 or 20 board feet of foam in them: tigerfoam, or 
www.rhhfoamsystems.com. There's a lot of waste involved in using one of 
these (big metal cannisters, plastic guns, etc) but if you were 
comparing it to buying 100 16 oz. foam cans at Home Depot, it would 
likely be less environmentally onerous. Opened foams don't tend to store 
well, so try to open only what you need, though I've had some luck 
covering the ends of foam can straws with plastic, and then cutting off 
the last 1" or so. I can often store them for weeks that way. I am going 
to experiment with putting vaseline on the threads some time to avoid 
the occasional leak which locks everything up.

A very interesting, if slightly dated, sheet on insulation is available 
here:

http://www.buildinggreen.com/auth/article.cfm?fileName=040101a.xml

Look at the embodied energy table: makes me remember why I love cellulose!

Finally: I find the trick of looking up MSDS's a good way of getting 
around the mysticism and hand-waving that many manufacturers resort to 
when describing their products.

Good luck.

Keith