Cellulose or Fiberglass Insulation?

There have been quite a few concerns raised over the advantages and disadvantages of using cellulose and fiberglass insulation. Let this simple FAQ help you decide which one to choose.

I heard that fiberglass is a carcinogen. Is this true?

Yes but it may not be harmful. The U.S Department of Health and Human Services has assured that fiberglass, though carcinogenic, is not a threat to our lives when it is covered.

However, blown and batt type Fiberglass can become harmful when small glass fibers during installation are inhaled.

How can I avoid the negative effects of carcinogens in fiberglass?

• use a mask during installation
• cover the fiberglass after installation or buy fiberglass which is already covered. Fiberglass batt insulation is now commonly sold with kraft and paper cover. It also has perforations at the back to prevent water vapor build up.

Is cellulose a fire hazard?

Cellulose insulation is made using recycled newspaper which is of course, flammable. However, this type is already treated with chemicals safe for humans, making it a fire retardant. Being fire-resistant does not make it fireproof though. In essence, cellulose is combustible, while fiberglass simply melts.

How do I avoid fires if I choose cellulose?

To be safe, it is useful to follow these tips when using either cellulose of fiberglass:

• do not install it near an older type of recessed lighting fixture. The insulation traps light bulb heat, causing it to overheat.
• buy recessed fixtures which have built-in thermostats

Which insulates better?

The measure of the flow of heat through an object is called the R-value. If R-value is high, then it has a higher capacity for insulation. After settling, the R-value of fiberglass is 2.1-2.7 per inch. Cellulose after settling has an R-value of 3.0 per inch.

If you decide on fiberglass, buy the new type of loose fill fiberglass which does not settle and retains its R-value. Alternatively, you can also install fiberglass batt type over the loose fill or blown type.

Bottom line is, you should apply the necessary precautions after and before installing either fiberglass or cellulose insulation.