Cellulose Insulation Procedures

Consider this green insulation for new or existing homes

By Robert Ferguson

Photo by iStockphoto.com

Cellulose insulation is gaining popularity as a green insulation choice for residential and commercial buildings. The most common type derives from shredded newspaper. Other types include cardboard, straw, hemp, corn husks, and sawdust. Cellulose is composed of 75 percent to 85 percent recycled paper fiber. The other 15 percent is sodium borate, boric acid or ammonium sulfate that makes it fire resistant. Cellulose uses more recycled material than any other form of insulation and uses less embodied energy than fiberglass.

Types

The four modern types of cellulose insulation are dry cellulose loose fill, spray applied cellulose wet-spray, stabilized cellulose and low-dust cellulose. For do-it-yourselfers, home improvement centers and building suppliers sell cellulose in bags for easy delivery to the job site.

Installation Procedures

For existing homes, blow dry cellulose into wall cavities through holes cut into the drywall. Insulate the attic by dispersing the material evenly throughout the area. Spray-applied cellulose is mixed with water and sometimes small amounts of adhesive. Blow this type of cellulose insulation into new wall cavities before drywall insulation. Wet-spray cellulose eliminates the need for temporary retainers that dry cellulose requires for new construction. Stabilized cellulose, mixed with small amounts of water to activate an adhesive, resists settling which reduces the amount of insulation needed. This is particularly attractive for attics, as less insulation will have less weight, reducing the chance of ceiling sag. For applications where dust is a concern, use low-dust cellulose. The cellulose has small amounts of oil added to control the dust it produces during installation. The cellulose requires a specially designed blower for installation. Some home improvement centers will loan you the blower when you buy the cellulose.

Advantages

Cellulose is made of recycled materials that would otherwise end up in a landfill. It does not produce ozone-depleting gasses. Properly insulating a home or business saves energy, reducing costs associated with its production and lowering carbon emissions. Blown insulation avoids obstacles that would interfere with other types of insulation. The borate in cellulose provides resistance to mold, insects and rodents.

Disadvantages

When insulating an attic, you must be able to enter and maneuver your way around it. Cellulose usually creates an irritating dust when installed. Using dust masks or the low-dust cellulose reduces this problem. If you're not up to the physical demands of the task, hire a qualified technician for the project.