How Long Will My Insulation Last?
As a homeowner, you’re probably conditioned to expect that important components of your home are just plain going to fail at least once—and quite possibly multiple times—over the course of your “stay.” Hot water heater? Every 10 years. Furnace or central air conditioner? Maybe 15 years. Roof? Every 20, maybe 25 if you’re lucky. You might be pleasantly surprised to learn, then, that most insulation materials can remain in service quite a lot longer. In fact, manufacturers of various insulation types, including foam, fiberglass, cellulose, and house wrap frequently claim an expected product lifespan of 80 to 100 years … “under ideal circumstances.” Wait … hold up a second. “Under ideal circumstances”? What exactly does that mean? Well, here’s the thing. Insulation isn’t indestructible. Weather, humidity, pests, and even gravity can all take their toll. Roof leaks and water damage can cause mold and mildew to develop. Loose fills can settle and become compacted. Gaps can develop, which causes a drop in the R-value performance—and a corresponding increase in draftiness and heating and cooling costs. And as you might have guessed, not all insulation types resist the practical effects of time equally well. Fiberglass batting, the most common insulation type, is especially vulnerable to environmental hazards:
- It can fall out of attics and crawl spaces after just 15-20 years.
- It can settle and compact over time due to gravity.
- It doesn’t resist mold or mildew as well as foam.
- It can make an inviting home for burrowing pests.
- Spray foam holds its shape over time. It won’t sag, compress, or fall out of place.
- Spray foam is a lot better at resisting water seepage, vapors, and mold and mildew growth. Closed cell foams are particularly good at this, but even open cell is much better than most common non-foam alternatives.
- Spray foam resists dust, dirt, and other contaminants, which can reduce the effectiveness of other types of insulation.
- Spray foam repels pests, from rodents to termites, so unwanted critters can’t compromise the energy efficiency of your home.