Blowing Insulation into Your Attic

Cellulose Insulation – How to Blow Cellulose Insulation into Your Attic.  Blowing insulation into your attic is a fast and easy way to save money on your energy bills. Blowing insulation requires a special machine to break down the insulation into tiny pieces and blow it through a long hose. Both Lowe’s and The Home Depot offer free rental machines with a minimum purchase of the insulation, usually about $250.

Blowing insulation is usually a 2-person job, one person puts the insulation into the machine and the other person holds the hose and directs the flow of insulation. You can do it by yourself by loading up the machine and running extension cords into the attic to turn the machine on and off. But I’d recommend convincing a buddy or your wife to help you out.

Prepare the Attic Place a plywood walkway down for easy and safe access in the attic.

Determine coverage requirements by measuring length and width of your attic space. Determining the square footage of the 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.

To keep the attic access free, and avoid blowing cellulose on top of it, place cardboard blocking around the access.

Step 1. Put a plywood walkway for safe access in attic.

Step 2: Protect Fixtures and Vents

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.

Also install metal flashing around heating fixtures, chimney flues and any other fixtures that generate heat.

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.  Use flashing to block off recessed fixtures and keep insulation material away from recessed lights.  Use flashing around fixtures that generates heat.  Soffit vent chutes helps maintain air circulation.

Step 3: Choose and Purchase the Cellulose

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 the coverage area in square feet, and the R-value you’d like to achieve, you can determine the cost by following the chart.

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.

Step 4: Install the Cellulose

As the cellulose is blown in, use a tape measure to gauge thickness.

Work away from the farthest corner of the attic, back to the attic access. This way, you won’t need to walk through the cellulose once the job is done.

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.