Image Credit Carl Seville
Fiberglass has never been my favourite insulation, and I got really upset with Owens Cornings's "Pink is Green" advertising campaign a few years ago, noting that there is more to being green than simply saving energy. But I had to concede that it was cheap and if properly installed, safe, inert and effective.
But Carl Seville at Green Building Advisor won't even go that far; He thinks batt insulation should be banned.
Carl's point is that batt insulation has to be installed properly to be effective, and that it rarely is. Sprays fill every void, but batts do not unless carefully cut and split around wires and boxes. He writes:
Recently, I have inspected several homes that were insulated with fiberglass batts, and, not surprisingly, the quality of the installation was dismal. What I saw could have been an instruction manual on how not to insulate a house. Batts were cut 2 to 3 inches wider than the stud spacing and crammed into the cavities. Not a single batt was split around a wire or pipe, nor were they cut around electrical boxes. Air barriers everywhere were missing. In most cases, the contractor used batts because the homeowners were unwilling to pay the extra cost of a blown-in product, and the contractor was unwilling to absorb the cost of the upgrade.
So while fiberglass batts are cheap, customers are getting what they pay for. They are pushed into the stud spaces in a hurry by guys getting paid by the square foot, with little incentive to do the perfect job. Building materials are part of a system, and it all has to work together; if there are gaps at the top and around boxes, or holes in the vapour barrier, then the system doesn't work. Seville concludes:
I actually don't have a problem with batts as a product, but as an installed system, they rarely make the grade. I realize that there are some high-quality installers who are capable of doing an excellent job, but they are few and far between. We get what we pay for, and when we only pay bottom dollar for fiberglass batts, we get the performance we deserve. Unfortunately, the person who suffers is the homeowner who usually doesn't know any better.
In the end, Carl suggests that a ban might be too extreme, but perhaps batts should be used only by trained contractors and that their installation be supervised and the installers be held accountable. He notes that this would make it more expensive, perhaps costing as much as the better blown-in materials.
I should also note that this applies not just to fiberglass batts, but all batt products, including the beloved ultratouch denim products. Sprays just do a better job of filling every crack and void. More at Green Building Advisor
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