When homeowners hear "fiberglass," they immediately picture the itchy pink rolls (batting) found in old sheds. Today's modern, loose-fill blown-in fiberglass is a radically different feat of engineering. Let's analyze its performance in the DFW climate.
The Pros
- ✔ Non-combustible: Glass fibers naturally will not catch fire, requiring zero toxic chemical flame retardants like cellulose does.
- ✔ Moisture Resistant: It does not absorb water. If exposed to a minor leak, it mostly dries out rapidly.
- ✔ Highest ROI: It's the cheapest material to install per R-Value point.
The Cons
- ✘ Low Density: Because it is light, it's terrible at blocking sound and air drafts without a separate floor seal.
- ✘ Settling: Over 15 years, gravity compresses the fibers, slowly reducing your overall R-Value.
The Bottom Line:
Blown-in fiberglass is the most cost-effective way to get your home to R-38 or R-49. Provided you fully extract the old material and air-seal the floor first, it provides a massive, immediate drop in your summer electric bills.