How to Insulate Drywall

  • 4-20 hours
  • Intermediate
  • 500-1,000
What You'll Need
Drywall saw
Drywall tape
Drywall mud
Putty knife
Stud finder
Blown-in insulation
Insulation blower

Adding drywall is an obvious step to completing your home but if someone failed to insulate behind it then the drywall won't be enough protection for the home. When you insulate behind the drywall you are adding an extra layer of protection that will prevent loss of heat as well as keeping out cold air. It's much easier to insulate behind drywall before the drywall is hung. If you want to insulate your walls continue reading this article as it'll show you how to insulate behind drywall that has already been installed.

Step 1 – Removing Drywall

The remarkable thing about drywall is that you can remove pieces of it and the replace it and, if done correctly, you could never tell it had been removed. This is done a lot in order to insulate behind drywall as well as to access electrical, plumbing and to check for mold. Use the stud finder to locate the studs in the wall as well as any live wires that may be present. Determine the center of the section and mark it with a pencil. You will do this with the entire length of the wall as you need to insulate it entirely. Use the drywall saw to cut out a square large enough for the hose of the insulation blower to fit comfortably. Try to get the hole close to the top of the wall. Remove the cut piece from each section. Since the sections are not all going to be the same it may be a good idea to number them or set them in front of the section they belong to.

Step 2 – Insulate Behind the Drywall

This process can take some time but it is rewarding when you are finished. Insert the insulation blower hose all the way inside the wall toward the bottom. Turn on the blower. You will be able to feel the insulation fill the space between the studs. As soon as you feel the pressure, move the hose up until the crevice is full. Repeat with each section of the wall.

Step 3 – Patching the Drywall

As said previously drywall is fairly easy to repair but it does take some time, the right tools and the right information. Place the piece of drywall you removed back into the wall. Make it as even as you can. Once you are satisfied dip the putty knife into the drywall mud and gently spread it along the seams of the removed piece of drywall. Spread it out and feather the edges of the mud. Continue until the piece is sealed at the edges. Affix drywall tape around the piece and then spread more mud over the tape also fanning out the edges to blend it to the wall. After the mud has dried, sand it flush with the wall and apply more mud. Continue for a few layers like this until the piece if stuck fast and you can paint the wall.