Blown In Insulation Info

Blown-in cellulose is a popular alternative to fiberglass insulation. According to insulation specialist Richard Applegate, cellulose is a natural wood product, and 75 percent of what it's made from is recycled newspaper. Fire-retardant chemical additives give the material a class-1 fire rating, making it a very safe product.

One of the biggest advantages of using cellulose is its performance. In fact, because of its density, it has a higher R-rating than and outperforms many common insulation products. Its loose nature makes it easier to install into irregular spaces, creating a custom-fit monolithic seal over an entire area.

From both health and environmental perspectives, cellulose is considered a "green" product -- more ecologically sound than competing products. It doesn't contain formaldehyde, and cancer warnings are not required on its labeling. Since there are no glass fibers, as with fiberglass insulation, cellulose does not cause itch.


Materials:

Cellulose insulation (amount varies according to coverage area)
Cellulose blower (available to rent at most home centers and lumberyards)
Goggles
Mask
Cap or hat
20" cardboard strips
Stapler
Tape measure
10" metal flashing
Soffit baffles


Safety Alert: Cellulose dust is considered a "nuisance dust" rather than a hazardous material. An ordinary dust mask is sufficient protection but should be worn during the installation process. Goggles are also recommended to keep dust out of the eyes.



Steps:

 

1. Place a plywood walkway down for easy and safe access in the attic.
   
   
   
2. Determine coverage requirements by measuring length and width of your attic space. Determining the square footage of your attic will help you order the necessary amount of cellulose. To simplify measuring in a large attic, take each measurement in two steps. Slide a measuring tape to one side of the attic (eliminating the need to crawl all the way to the edge), and make a mark near the center point on the floor. Then slide the tape to the opposite side, measure out to the mark and add the measurements together. Once you have accurate length and width measurements, multiply the two numbers together to determine the square footage.
   
   
   
3. To keep the attic access free, and avoid blowing cellulose on top of it, place cardboard blocking around the access.
   
   
   
4. With any type of insulation, it's important to keep the insulation material away from recessed lighting fixtures. Use 10" flashing to block off recessed fixtures, maintaining at least 3" of air space between the fixture and the flashing.
   
   
   
5. Also install metal flashing around heating fixtures, chimney flues and any other fixtures that generate heat.
   
   
   
6. Soffit-vent chutes prevent soffit vents from being covered with cellulose, helping to maintain good air circulation in the attic. Use a stapler to install the chutes over the soffit vents.
   
   
   
7. To help determine cost when ordering cellulose, bags of cellulose have charts listing amounts of material needed -- according to specific coverage areas and desired R-values. If you know your coverage area in square feet, and the R-value you'd like to achieve, you can determine the cost by following the chart.
   
   
   
8. Once the amounts have been calculated and the cellulose purchased, work can begin on the process of blowing the material into the attic space with the specialized blower.
   
   
   
9. As the cellulose is blown in, use a tape measure to gauge thickness as you go. In our demonstration, a 16" depth was added to the attic.
   
   
   
10. Work your way away from the farthest corner of the attic, back to the attic access. In this way, you won't need to walk through the cellulose once the job is done.
    
    
    
11. Cellulose is blown in around soffit chutes, but the structure of the chute prevents the cellulose from blocking the soffit vents. Blow the cellulose right around the chute to get full coverage at the edge of the attic.
    
    
    
12. In our demonstration, the center portion of the attic was left exposed and uncovered since this area is to be used for storage and access.

With cellulose insulation, installed according to the Department of Energy's R-value recommendations, homeowners can usually realize a 20 percent to 50 percent savings on their utility bills. In newer homes, with fiberglass insulation already installed, cellulose can be installed over the fiberglass for increased savings.


Cellulose insulation is substantially more economical than fiberglass batts. A project of about 500 square feet would cost between $400 and $500 if professionally installed. For a do-it-yourselfer, the cost for the same area would be around $200. The total job for that area would generally take nonprofessionals about a day to complete.