Thursday, September 17th, 2009...2:00 am
Ins and Outs of Insulation
Today I learned more about insulation that I ever wanted to know. That’s because we determined that the traditional fiberglass insulation that our contractor had installed earlier this week–but hadn’t yet enclosed in drywall–had to come out.
This had nothing to do with the contractor or the quality of their work. This had everything to do with the noxious smell of fiberglass insulation, which has made my house almost unlivable. To most people it’s a mildly offensive odor that supposedly goes away over time. But I’m one of those people who is sensitive to smells, and there was no way I could live with the odor, or risk closing up the walls and not having the smell dissipate.
Turns out that nearly all insulation gives off an odor. The cause? The formaldehyde manufacturers use to bind the fiberglass together. Frankly, it creeps me out to think that there is formaldehyde gasses in my house right now. Isn’t that the stuff they use to embalm people after they die?
Anyway, I spent the better part of today looking for less-toxic options. Here’s what I found out:
* You can get formaldehyde-free fiberglass insulation.
A company called Johns Manville has created JM Formaldehyde-Free Insulation. Actually, nearly all of the company’s insulation products don’t use added formaldehyde, and it’s the brand I’m recommending my contractor get as a replacement. I’ve spoken with other people who are sensitive to smells like I am, and they’ve used this product to great (and odor-free) results. I found it available at my local Lowe’s store only.
* Fiberglass is actually made of recycled glass.
This was a new one on me. It doesn’t make it any easier or less itchy to work with, but it is recycled at least.
* You can get non-fiberglass insulation but you’ll pay a premium for it.
I knew that you could get insulation made from cotton or recycled denim. What I didn’t know was how much more expensive it was. Today, I spent a couple of hours looking into Bonded Logic UltraTouch denim insulation, which seemed perfect for our needs. However, it costs 3X as much as the formaldehyde-free insulation. And if my purpose in getting “non-toxic” insulation, if you will, was to avoid odors, then I’ve got to go with the one that doesn’t smell and doesn’t cost the most.
Anything else you think I need to know about insulation?
Did not know all that about insulation, surprised there is not a more foam option now that does not give off an odor.
And it’s not just the insulation… it’s also really important to make sure the house doesn’t leak excessively (which most do). (More on that at the link below…)
And ideally one gets rid of thermal bridges (due to the studs in the walls themselves having almost no insulating value) by either having some rigid insulation outside the studs, or strapped horizontally inside the studs with 2x3s so that the only “all wood” spots are where the studs cross the 2x3s. And there are more ways.
Other types of insulation which would for you:
- dense-packed cellulose (recycled newspaper)
- dense-packed fiberglass (“blown in batts)
- low-density-foam (LDF) like icynene
The cellulose is probably about the same price as the fiberglass and works better.
Some useful links for you:
on leaks:
http://www.greenbuildingadvisor.com/blogs/dept/musings/pinpointing-leaks-fog-machine
on insulation:
http://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/how-much-insulation-needed
on thermal bridging ideas
http://www.coldhamandhartman.com/upload/documents/BE07-WallSystemOptions.pdf
[...] brushes. (We wore gloves and protective eyewear, too.) It smelled surprisingly good–nothing sickening like the insulation our contractor originally choose–and went on easily. Now, we had to wait for it to do its job [...]