How to Blow Insulation in Walls

Insulating an existing wall, such as with blown-in cellulose insulation, is more challenging than attic insulation due to modifying both the exterior and interior walls. This home improvement project can be costly if it involves removing the wall covering to insulate your existing wall.

However, the energy savings and enhanced indoor air quality can make it a worthwhile investment.

That’s why the blown-in insulation method, particularly using materials like cellulose insulation, is a perfect choice for home insulations. It is less expensive and creates less mess during installation.

Understanding the pros and cons of different types of insulation, such as open-cell spray foam and blown-in cellulose, is crucial before starting the project.

Here’s how to blow in insulation in walls

  1. First, use a stud finder to locate each wall stud and horizontal block near or at the center of the wall’s height. It’s important to accurately identify these areas to ensure the insulation is effectively blown into the wall cavities. Then, use blue masking tape to mark each horizontal block and stud center. In some homes, a horizontal block is placed halfway between the top and bottom of a wall cavity. Some of the blocks are arranged in a diagonal row.
  2. Secondly, make a hole into the top of the wall cavity, approximately 6 inches below the ceiling, with a hole saw and drill. This hole should be created in the center between each set of studs. The hole size should be sufficient to allow the insulation hose to be inserted without causing damage to the wall.
  3. If your wall has diagonal or horizontal blocking, make a second penetration an inch or two underneath the block. Make a hole in the center between each set of studs. The insulation hole must be made regularly, filling one cavity at a time. This ensures even distribution of the insulation, such as blown-in cellulose insulation, and minimizes energy loss through the walls.
how to blow insulation in walls

  1. After that, you must remove the old insulation using a vacuum.
  2. This is where you start using the blow insulation machine. You can get the machine by renting them. Insert the blower hose into the first hole and direct the nozzle deep into the wall cavity. To make a seal, wrap a rag around the hose where it touches the wall. Have a partner to turn on the blower while you hang on to the hose. As the cavity fills, pull the hose back. How much to blow insulation walls is when you sense resistance and can no longer put insulation. Ask your partner to stop the machine.
  3. And for the final step, you need to replace the drywall cuttings and patch and paint over the holes on your wall.

How Much is the Cost to Blow Insulation in Walls

If we talk about the cost on how to blow insulation in walls, the answer may vary. It will depend on how big is the area of the wall that needs to be insulated, what material you use, and how you do the insulation. Generally, the cost per square foot ranges from $0.64 to $1.19.

If you do it yourself, your estimate for a 500 square foot area will range from $145 to $200. Add $150 to $300 for manpower for a professional job, and roughly it will cost $300 to $500 for 6 hours of work.

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Insulator is a skilled author and Insulation expert with years of experience in the field. He has authored several articles and books on various aspects of insulation installation, maintenance, and repair.