When it comes to insulating your home, the goal is to cost effectively protect your home against moisture and the elements while reducing your overall energy costs. In the past, fiberglass insulation was the option for home insulation. However, spray foam insulation is growing in popularity. In this post, we hope to answer the question:
Which is better, spray foam insulation or fiberglass?
First let’s take a look at fiberglass insulation. Fiberglass insulation works by trapping air inside minute glass fibers. This slows the transfer of heat and insulates your home. The fiberglass is placed on the wall in sheets, typically by a professional, and usually comes in rolls. It has no harmful emissions; however, it must be handled with care, as it is made up of tiny glass particles. If the fiberglass stays dry, it can last 10-25 years. The R-value of fiberglass insulation is 2.2 per inch of non-aged value, and it loses its R-value over time. Due to the kraft paper on the batts, there is potential flammability. In extreme cold, it tends to lose heat quickly. In addition, it offers low sound barrier efficiency and adds no structural integrity to the wall. It is a fairly inexpensive method of insulating a home; it costs around $0.40 per square foot.
Now let’s investigate spray foam insulation. This type of insulation comes in two forms – open cell and closed cell. Open cell is mainly used as an air barrier, and closed cell is used as an air, moisture, and vapor barrier. With open cell foam insulation, there is minimal air leakage; however, there is no air leakage with closed cell insulation. The R-value of open cell insulation is 3.5 per inch, while the R-value of closed cell is 6 to 7 per inch. In addition, spray foam insulation does not lose its R-value over time. The lifetime of foam insulation is 80 years, and it also increases the structural integrity of the wall as well as providing a high level of sound barrier efficiency. In cold weather, there is no difference in its performance. Spray foam insulation does have a higher up front cost. However, because of its long life and greater energy efficiency, it could be said to be well worth the additional initial price. A homeowner might expect to replace fiberglass several times compared to the lifetime of foam insulation, and their energy bills will be higher as well.
After carefully reading the information above, if you are still wondering which is better, spray foam insulation or fiberglass, the answer may be in looking at the long term goal you have for your housing needs. Are you looking for a slightly lower up front cost that will need to be periodically replaced and that can still allow air leakage, moisture leakage, and may or may not save as much energy over time? Or is this initial price of foam insulation worth the long lifetime, the greater energy savings, the more efficient sealing, and the added benefits of wall structure integrity and sound barrier? Over the long haul, it would seem that foam insulation is the better, more cost-effective choice.
Still have questions? If you want to know more about the benefits of foam insulation over fiberglass, visit Airseal, and we’ll be glad to answer any questions you may have about keeping your home protected and your energy bills lower.