Spray Foam vs. Fiberglass: Two Insulations Duke it Out for Champ Status (Part 2)

If you were following along, we were discussing spray foam and fiberglass insulation, specifically which one was better value for money. We've already mentioned that there's no clear-cut answer to that because the two types of insulation can't be compared, which we discussed in our introduction.

Today's post goes a little more in depth.

ROUND ONE -- Fiberglass as Insulator

Fiberglass insulation has been the industry standard insulation for decades because it’s usually easy to install, quick to put in place, and relatively inexpensive. Sure, it’s a decent insulator, doesn’t significantly add to building costs, and can be retrofitted easily and inexpensively for existing buildings. But while fiberglass has been the big man on campus for a long time, it doesn’t solve all of a building’s energy problems. That’s where spray foam comes in. More on spray foam in future posts, but first let’s touch on which is perhaps the number one problem plaguing most buildings today: air leakage.

Eliminating air flow is critical to a building’s overall energy efficiency and creating a high-quality building envelope. But because traditional forms of insulation, including fiberglass, are not air barriers, wherever these types of insulations are installed, approximately 40-50% of an energy bill is related to air leakage. That’s a lot of money and energy being wasted.

Fiberglass, in other words, is an insulator only. It does little, if anything, to combat air leakage. 

Read Next: Round Two -- Spray Foam as Insulator and Air Barrier