How Do I Blow Insulation into the Space Between Floors?

Updated February 21, 2017

Blown-in insulation is the perfect way to better insulate any home and cut down on energy costs. One type of blown-in insulation is cellulose, which is a "green" product that is much cheaper than other forms of insulation, including fibreglass. Blown-in insulation can be added to the space between the floors in a very short amount of time, and can help you save on your energy bills in the long run.

Measure the length and width of the space to determine how much insulation will be needed. Multiply the length by the width to determine how many square feet there are. Decide on the R-value that the insulation needs to be. The higher the R-value, the thicker the insulation will be. Most R-values are either R13, R19 or R30. Calculate the number of bags you'll need, based on the R-value. One bag of cellulose insulation with an R-value of 13 will cover 40 square feet.

Put cardboard backing around the access points to the space. This will help avoid debris from the insulation coming through. Cover all recessed lighting fixtures with 10-inch flashing and leave at least three inches of air space between the lighting and the flashing. Attach metal flashing around any other fixtures in the room that produce heat, such as chimney flutes and heating fixtures.

Put on the safety glasses, the dust mask and the gloves. Dump the bags of insulation into the top of the blower. The insulation will sit in the tank of the blower until it is turned on. Start at the back corner of the room and turn on the blower. Point the hose of the blower at the desired spot on the floor. Fill the space until the desired thickness is reached for each space. Move on to the next space, working from side to side and toward the front of the room to avoid walking over the insulation after it has been installed.

Allow the insulation proper time to dry before walking over it. With the amount of moisture in the insulation, this process generally takes 36 hours, but can vary depending on the R-value.

Things You'll Need

  • Tape measure
  • Safety goggles
  • Insulation
  • Dust mask
  • Insulation blower
  • Gloves
  • Metal flashing
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Alexander Callos began writing in 2005 for "The Lantern" at The Ohio State University and has written for various websites, including Bleacher Report, Top Ten Real Estate Deals and Columbus Sports. He has published articles for CBS Sports, and other websites. He graduated in 2007 from The Ohio State University with a bachelor's degree in public affairs journalism.