An attic in a home prepared for insulation to be blown in

Blown-in attic insulation effectively improves your home’s energy efficiency and saves on heating costs. While it may seem daunting, it’s a simple enough process to do on your own.

This article will provide a more thorough guide on how to blow in attic insulation on your own, with tips for working more efficiently and effectively. 

So, let’s get into it!

How Do I Blow in Attic Insulation?

The process of blowing in attic insulation includes measuring your attic space, sealing any air leaks, installing or repairing vent chutes, damming the gable, and then blowing in the insulation. Inspect your results after you’re done and seal any remaining gaps or holes to complete the application. 

However, there are some advanced techniques you can use to improve the efficiency of your insulation job. Let’s consider these in detail.

1.) Measure Your Attic Space

The first step to insulating your attic is to measure the space. This action will help you determine how much insulation you’ll need. 

  • Use a tape measure to determine the square footage of your attic space and the depth of your desired insulation. It’s also important to note any obstructions or other details that may impact your ability to insulate the area. 
  • Once you have calculated the square footage, look up your current insulation on an R-value chart. This figure will help you determine how much insulation is required to achieve your desired level of energy efficiency.

Cellulose and fiberglass are some of the most common types of attic insulation, so you may want to look up these materials on a chart to compare their R-value per inch. 

However, cellulose insulation is an excellent choice as it is made from recycled paper, and it’s easy to install using a blower machine. In addition, its high R-value and ability to fill in cracks and crevices make it ideal for attic insulation.

a yellow bag filled with grey broken up pieces of cellulose insulation
The ecologically-clean cellulose insulation, insulation from recycled newsprint

2.) Get the Right Tools and Materials

Blowing in attic insulation can be a big job. So before you get started, make sure that you have all of the necessary tools and materials on hand. 

The tools you will need include:

  • A blower with an appropriate hose and an extension cord
  • Caulk gun
  • Safety gear, including a hard hat, safety glasses, work gloves, and knee pads
  • A measuring tape and chalk or pencil to mark the final insulation level
  • Attic access ladder or scaffolding to safely reach the attic space

In addition, you will need the following materials:

  • Cellulose insulation
  • Scissors or shears for cutting the insulation if necessary 
  • Duct tape
  • Caulk or expanding foam sealant to seal any attic bypasses or gaps
  • Weatherstripping to seal around the chimney, vents, and other openings
  • Pipe insulation to wrap around exposed water pipes in your attic
  • Attic vent chutes or baffles, if necessary

3.) Seal Attic Bypasses and Wrap the Water Lines

Once you have all of the required tools and materials, the next step is to locate air leaks in your attic space and seal them.

Using a high-quality caulk or expanding foam sealant, fill in any gaps and air leaks around the chimney, vents, pipes, and other openings. As an added layer of protection, you may also wish to wrap exposed water pipes in your attic with pipe insulation. 

A technician applying metal-backed tape to an cylindrical duct to prevent air duct leakage

This step will not only help prevent heat loss but can also help protect the water lines from freezing in cold weather.

4.) Install or Repair Vent Chutes

In addition to sealing attic bypasses, you should also review and assess the condition of your attic vent chutes or baffles. If they are damaged or missing, it’s essential to replace them as soon as possible so that you can control airflow appropriately in your attic space. 

Fortunately, installing or repairing vent chutes is a relatively simple process:

  • First, start by removing any existing chutes that are damaged or broken.
  • Next, measure and cut new ones to the appropriate size using scissors or shears. 
  • Use duct tape to attach the new chutes firmly in place. If necessary, you can also use expanding foam sealant to secure the baffles further and prevent air leaks in your attic.

Be sure to use high-quality materials that maintain outside moisture while allowing airflow in your attic space.

5.) Dam the Gable

To properly insulate your attic, it’s vital to ensure that heat cannot escape through the roof. You can do this by installing a dam or barrier at the top of your attic space, which will help reduce airflow and prevent heat from escaping your home. 

You can use various materials such as cardboard, plywood, insulation batts, or metal flashing to create a dam in your attic. Cut the material to size and attach it to the top of your attic with nails or screws. 

A worker installing insulation between the rafters in a roof.

Ideally, the dam should be wide enough to block airflow but not so broad that it interferes with the vents in your attic. 

6.) Insulate the Attic Access

Sealing and insulating the hatch or door leading to your attic can help prevent heat from escaping your home and improve energy efficiency

A straightforward way to do this is to install an insulated cover for the attic access to help insulate the hatch and provide a barrier that prevents drafts and heat loss. Use an insulation board and insulating tape, or purchase a premade attic access cover to seal and insulate the hatch. 

To install the cover:

  • Remove the existing attic access door or hatch
  • Measure and cut the new insulation board to fit over the opening, leaving a small amount of space around the edges
  • Seal the edges of the insulation board to the opening using insulating tape or an adhesive caulk
  • Attach the insulation board to your attic access with weatherstripping tape, ensuring it is tightly sealed
  • Re-install the attic door or hatch

7.) Mark the Final Insulation Depth

Once you have installed all of your attic insulation materials, it’s essential to mark the final depth. This step will allow you to easily monitor and assess the amount of insulation installed and ensure that no gaps have been missed.  

Using measuring tape, mark the final insulation depth on an interior wall or joist in your attic space so you can easily monitor the amount of insulation added. 

The proper depth can vary depending on the insulation you are using. However, filling your attic space with insulation of about 10-14 inches (25-35 cm) deep is recommended to provide the best possible attic insulation performance.

8.) Set Up the Blower

Now that your attic is properly sealed and marked, you can install the blower to blow the insulation into the space. 

Setting up the blower is relatively simple:

  • Move the blower into a central location near the attic hatch or door. Be sure to do this slowly and carefully, as the machine can be heavy and difficult to maneuver. 
  • Connect the hose to the blower and direct it over the desired area of your attic. Use a long hose attachment for the insulation to reach all corners of your attic. 
  • Crumble the insulation into the blower hopper, following the manufacturer’s guidelines.
A homeowner in a garages pours blown-in cellulose attic insulation into a hopper
Courtesy of Corey Binford
  • Run the extension cord from the blower to an electrical outlet, plug it in, and turn it on.
  • Check to make sure that the blades are functioning properly. If you notice any issues with airflow or performance, you may need to replace or repair the blower. 
  • Adjust the blower speed and run a test to ensure no air leaks or gaps in your insulation. If you notice any issues, make the necessary adjustments and run another test until you are satisfied with the results. 

Have a helper on hand to assist you during this process, as it may be difficult and dangerous to hold the hose while manually controlling the blower.

9.) Blow in the Insulation to the Final Depth

Once you have successfully installed and tested the blower, it’s time to blow the insulation. 

The following steps will help you blow the attic insulation into the space: 

  • Wear a dust mask, safety goggles, and thick gloves to protect yourself from the insulation. 
  • Let the insulation flow onto your attic floor, beginning at the lowest and working to the highest point. Use a comprehensive sweeping motion when blowing, not leaving any gaps or holes. 
A homeowner blowing in cellulose attic insulation
  • Slowly move the blower along the attic floor, directing the airflow and ensuring that all areas are covered with insulation.  
  • As you blow in the insulation, monitor the depth marker and adjust the speed of the blower accordingly to ensure that you reach the final depth. 
  • Check regularly for any visible gaps or leaks and make the necessary adjustments.
  • Once you have blown in all the insulation, inspect your attic space for any remaining gaps or holes. Then, use caulk or spray foam to seal these areas and complete the insulation installation process.


Blowing in attic insulation on your own can be a bit daunting at first, but with the right tools and a few simple steps, you can do it quickly and easily. 

If you are looking to save money on your energy bills or improve the comfort and performance of your home, blowing in attic insulation is an effective way to do so. So why wait? Get started on this simple DIY project and reap the benefits immediately!


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