Fiberglass blanket insulation is a dense fiberglass-based insulation that is intended for areas that have large openings, such as cathedral ceilings.
Fiberglass loose-fill insulation is created from glass that's spun into fibers. The materials include 20 percent to 30 percent recycled glass. Loose-fill insulation is applied using a blowing machine. The machine is designed for areas such as attics or inside walls and covered attic floors.
For safety, regardless of which insulation you use, be prepared. Wear a respirator to keep glass particles from your throat. Gloves, goggles and long-sleeved shirts are also recommended.
Mineral Wool Insulation
Mineral wool refers to rock or slag wool. Rock wool is a man-made material that includes natural minerals such as diabase, and slag wool is also man-made and has furnace slag (the deposits that form on molten metal).
Mineral wool contains 75 percent recycled product. It's fire-resistant and can be used in batts (blankets) and loose-fill. This product is dense, fits wall cavities tightly and is less prone to thermal losses than fiberglass products.
Plastic Fiber Insulation Material
Plastic insulation is made from recycled milk bottles. Fibers are made into batt insulation, similar to fiberglass.
The materials are treated with a fire retardant. It won't spread flames, but will melt if exposed to fire. Plastic insulation doesn't cause the issues that fiberglass provides. But it is difficult to cut with basic tools.
Natural materials such as cotton and sheep's wool are another option for your insulation needs.
Cotton consists of 85 percent cotton and 15 percent plastic fibers. They are treated with borate, a flame retardant and insect and rodent protectant.
One product uses recycled bluejeans. This product is very eco-friendly as it takes little energy to make. Cotton comes in batt and is nontoxic, which means you are not required to use respiratory or skin protection. One downfall is the cost, which may range from 15 percent to 20 percent more than the fiberglass materials.
Another popular insulation is sheep's wool. Similar to cotton materials, it also possesses borate.
More Natural Insulation
Straw insulation fuses the product into boards without adhesives. The technique originated in the 1930s, and panels are 2 to 4 inches thick. They serve another purpose as a sound-absorbing material and are used primarily for internal walls.
Yet another unique insulation is hemp. A relatively new method and not common to the United States, it offers similar thickness to other materials, including fiberglass insulation.