JM Spider Spray Fiberglass Insulation
All,
I am in the process of designing and building a Paasive House in Essex County, NJ. We are CZ 4, although the county just a few miles from the lot is CZ 5. We get hot humid summers and cold snowy winters 21F as I type.. I am trying to avoid using high GWP insulation products, so cellulose seemed like a good idea. I just had some put into my existing home’s attic floor. Simple enough for that location, but adding to walls in the new home seems like a very labor intensive project. I recently read an article on the JM Spider product. It seems like an easy enough product to work with, low GWP, fast install, higher R value than cellulose. Cost seems to be more than cellulose, but much less than spray foam. If anyone here has used the product before, please let me know what your experience was and if you would recommend using the product in the construction of a PH.
Regards,
Jon
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Replies
Jon,
Here is a link to an article that you may want to read: Getting to Know Spider Insulation.
Spider is designed as wall insulation, not for open-blowing on attic floors. If used in an attic it would need a top side air barrier to perform as well as cellulose at any given R-value. If blown at only 1lb density and with no top-side air barrier the performance would take a significant hit, but might be OK if blown in mesh at 1.8lbs+ density.
http://www.jm.com/content/dam/jm/global/en/building-insulation/Files/BI%20Toolbox/T07-016JMSpiderOverheadApplicationV2.pdf
Thanks Martin. That was actually the article that got me thinking about the Spider product. I noticed it was dated 2013 and I could not find any other articles. I was able to find some YouTube videos and some info on JM's website, but that is about it.
Thanks Dana. Sorry I did not mean to imply that I would use it in the attic floor, apparently they have a product called ClimatePro for that which does not require a blowing agent. What I learned from the cellulose attic floor install was that cellulose is quite messy. As for a wall cellulose install, it also seems a bit cumbersome to first put up a webbing, stapling every 2 inches, then cutting a hole in it, inserting a hose and blowing in the cellulose 1 foot at a time while estimating 3.5 to 4.0 lbs/cf when you can just spray on the fiberglass, trim it in one shot with a scraper and then go back and install a VB if needed. It dries quickly, does not require special breathing apparatus like foam, excess is just vacuumed up with a hose, trims much easier than foam, etc.
Here is a link to a somewhat cheesy video from JM that includes a link to,the brochure. Look like a great product, but has not seemed to catch on. There has to be a catch,
http://www.jmhomeowner.com/products/product.asp?category=Blownin&Product=Spider
Unlike Spider, JM Climate Pro is designed for open blown applications.
Damp sprayed cellulose goes up in exactly the same way as damp-sprayed Spider, and does not require webbing. It's lower R/inch than Spider, but it's also has a thermal mass benefit at high-R, and it's more protective of the structural wood due to it's superior moisture buffering capacity. It only needs mesh if its being dense-packed or dry-blown.
Got it, thanks Dana.