It’s What’s Inside That Counts
It’s What’s Inside That Counts
November 8, 2013 by Taylor Studios
With winter on the horizon and nighttime temps below freezing, staying warm is on my mind. While I don’t mind wearing extra layers, comfort isn’t the only concern when it comes to heating your home. I’ll discuss in another blog how windows and properly sealing your home can cut your heating bills, but the letter for the day is “I”, for insulation. The classic pink fiberglass rolls dominate this field. I know it does a great job, but I hate working anywhere near the stuff, due to the fibers getting stuck in my clothes and skin. While it is still the most common form of insulation, fiberglass is not the only choice in an increasingly green marketplace.
One of the more surprising options I discovered was . It clearly is a great insulator (or else, why would a sheep bahhh-ther growing it?), it’s very renewable, and when you need to replace it, it’s completely biodegradable. Wool has none of the allergy problems of fiberglass, and it’s safe to handle with bare hands. Wool’s outer layer is water-resistant, while it’s inner layers can absorb water while not feeling wet. Wool insulation extinguishes itself when burned, and it has been treated with environmentally-safe borates to resist insect damage and mold. It is rather expensive, reaching around $2/sq.ft.
Closely related to wool is cotton insulation, another fiber replacement. Derived from old and factory scrap denim, cotton insulation is also treated with borates. It can be installed in rolled batts or blown into place. Like wool, cotton muffles sound transmission better than fiberglass. Cotton tends to absorb water, so care must be taken to keep it dry. Cotton tends to be about twice the cost of fiberglass, but it doesn’t cause allergic reactions and can be installed without any protective clothing.
The oldest fiberglass alternative, cellulose, is derived from recycled newspaper. It has a higher R-value than fiberglass and costs about the same. Cellulose has been used in the Northeast for decades, and while it is blown in, it can be applied to walls and roofs with .
Moving away from fibrous products, polystyrene foam sheets are a commonly seen choice in new construction. Easy to cut, handle, and install, these sheets have a high R-value and add to the structural integrity of your walls. While not the greenest of the choices due to the petroleum-based polystyrene, there are versions that contain .
Another foam product growing in popularity is polyicynene or polyurethane spray-on insulation. Both products are applied as a thin skin sprayed directly onto the studs and walls. The skin expands on contact up to 100 times its original volume, which looks amazing when you watch it. It cures quickly and becomes rigid, sealing the walls completely. In fact, the seal is so tight, you have to make sure you have the space ventilated properly. Spray-on insulation is up to three times as expensive as fiberglass.
As with any building material, what is greener depends upon what you think is the most important factor. Cost varies widely, so do your homework. If you have first hand experience with one of these alternatives, tell us how happy you are with your choice!