Replies

1. GBA Editor
   Martin Holladay | Mar 15, 2013 07:51am | #1

   Oak Orchard,
   Good questions, and not easy to answer briefly. I think that you should be satisfied with the products of any manufacturer. However, the larger manufacturers are more likely to provide good technical help. I'm most familiar with the products and technical service at National Fiber and U.S. Green Fiber, which are both excellent companies.

2. 
   Oak_Orchard | Mar 15, 2013 10:32am | #2

   Thanks, Martin, that is exactly why I posted. You note two brands with very different ingredients: Green Fibre (sold at Lowes and HD) is heavy on the sulfates and it's a significant fraction of the bulk material. National Fibre, on the other hand, is sulfate free, and makes its selling points by focusing on the use of pure boric acid.

   If for example, you look at the claims of installed R-values, there are differences between companies, contents, etc. Perhaps fire resistance ratings and insect and mould protection ratings are also different.

   Are there safety issues such as dust inhalation; pyrophoricity of the dust; chances of explosion during installation; etc.? How come we don't hear of dust explosions associated with cellulose installs?

   http://fire.nist.gov/bfrlpubs/fire81/art010.html

   What about health of installers and health of homeowners due to chemistry and ingredients?

   http://npic.orst.edu/factsheets/borictech.html

   I have yet to see anything on ease of installation; flow and plasticity of the material; set up and holding power of the product once pressurized; optimum tube and hole size, distance from pressure barrier, etc for getting desired densities; achieving best back-pressures; etc.

3. 
   Kopper37 | Mar 15, 2013 12:02pm | #3

   Green Fiber produces a number of cellulose formulas. If you are interested in an all borate formula, then you can use their 765LD for both dense pack and loose fill.

   http://www.greenfiber.com/related_products_residential_construction.html

   National Fiber has a quality product too---and their technical support is excellent.

   Pyrophoricity? R-value, fire resistance, and insect resistance differences? I think you are getting lost in the details, looking for issues that don't exist.

   The borate compounds used to treat cellulose (for fire and insect resistance) have a very low toxicity level---below that of table salt. That said, the manufacturers recommend that you wear a mask when handling the product.

   You would do well to pick either one the manufacturers, follow their installation guidelines, and talk to their technical departments if you have further questions.

4. Expert Member
   Dana Dorsett | Mar 15, 2013 01:33pm | #4

   Most of the dust during installation of cellulose is the fire retardent, not cellulose fiber- its hard to torch-off a cloud of fire-retardent, eh?

   Borates are non-volatile- they don't hang in the air, can't move through walls, etc. and have (as Daniel points out) very low human toxicity. The only real exposure hazard is during installation- once it's buttoned up in a wall, it stays there.

   Borates ARE toxic to the gut flora of wood boring insects (carpenter ants/wasps/termites ,etc) who need those protozoans to process injested wood, and will kill the host insect by depriving them of nutrition. This is true even those insects (like carpenter ants) who don't eat wood for nutrition, since the accumulating wood-cellulose interferes with the rest of their digestion. Since those insects cannibalize the weak & dead, even the individuals that didn't eat the borates are killed, and since starvation takes time, even remote nests can be eradicated. This makes high-borate versions of cellulose a more-desirable insulation material in areas where infestations of wood boring insects are common. (Though proper moisture management of the building assemblies is also a critical first-order preventative step.

   I have no ideas what "artificial boric acid" is. If it's chemically identical H3BO3, who cares if it was synthesized from other feedstocks vs. dug out of a hole in the ground somewhere?

   In my local market I've not seen the "...wide variation in retail price...". Any formulation any vendor the prices seem to always be within a 20% window f.o.b. the distributor's yard, and I've even had all-borate goods from one source come in under the price of sulfate-bearing goods from another source- I'm guessing it just depends on spot market local demand. Typical premiums for all-borate material is in the 5-10% range, but that's "in the noise" of the total project cost variations. Clearly YMMV.

   National Fiber is just one vendor that I've used for dense packing, but since the distributor is quite close to me, it's mostly an ease of access thing. I've been satisfied with how their CelPak dry-blow goods install, but can't say that it's dramatically easier or harder than other vendor's goods. (I'm not in that biz, but I've done my own dense-packing ever since acquiring an insulation blower a handful of years back.)