If the gaps surrounding your home’s windows aren’t properly insulated and cold air filters into your home on nights when it is chilly outside, remove the wood casings that surround them and apply an even layer of foam insulation in each gap. After finishing, your home’s interior will be more energy efficient and you will remain comfortable on frigid nights.


  • hammer
  • power drill
  • pry bar
  • putty knife
  • bottle of soapy water
  • scrub brush
  • sponge
  • towel
  • face mask
  • rubber gloves
  • can of foam insulation
  • utility knife

Loosen And Remove The Wood Casing And Eliminate Old Insulation

Use the claw on the back of a hammer or power drill to remove hardware that is attached to each window casing. Remove the wood casing by inserting the tip of a pry bar under the edges of each piece. Once the wood is loose, pull the casings away from the wall.

Put on rubber gloves and a face mask to prevent being exposed to chemicals that the insulation is made out of. Inspect the gaps that run around each windowpane and remove old insulation from all of them with a putty knife. If some of the insulation is difficult to remove, rub it firmly with a soapy scrub brush. Once all of the old insulation has been removed and disposed of, eliminate soapy residue from each gap’s interior with a damp sponge. Dry each clean surface with a towel.

Apply An Even Layer Of Insulation

Fill the gaps halfway with an even layer of spray insulation. Use a type of insulation that is designed for use around windows and doors. This variety is formulated to expand with less force than standard types of insulation. As a result, you will not need to worry about damage to the casings or windows. The insulation that was applied will expand within a few minutes. Once this occurs, reattach the window casings by lining them up next to the sides of each window and securing them with pieces of hardware.

Remove Excess Insulation

If you applied too much insulation to any of the gaps and you see that it is seeping through the edges of the casing pieces, wait for the insulation to cure before removing it, which may take several hours. Use a utility knife to remove the excess pieces of insulation. The foam insulation that you applied will help keep your utility bill down and help you remain comfortable on a daily basis.