Insulate Garage Walls Already Dry-walled: How To

As is often the case with attics and basements, the garage is a place where insulation may not have been used during initial construction. This may not seem like much of an issue if your garage is kept reasonably warm because it’s connected to your home, or if you make an effort to keep it heated during the cooler months. Even if this is the case, you could still be wasting more energy than you may realize if your garage walls aren’t insulated.

You may be wondering if it’s even possible to insulate garage walls if they’re already drywalled. The short answer is yes – and it can be done using techniques that are not entirely complex. Now, here’s how you can accomplish this goal.

Insulation You Can Use to Insulate Dry-walled Garage Walls

Blown-in Insulation

Blown-in insulation is what’s normally recommended for garage walls that already have dry wall. It’s a cost-effective way to enjoy the many benefits of insulated walls without the need to worry about reapplying drywall.

What Blown-In Insulation Is

Also called loose-fill insulation, blown-in insulation is a type of insulation that’s blown or sprayed into place. It’s typically installed with a blowing machine, which allows for easy application without the need to completely remove drywall. It’s ideal for attics, basements, and other places with wall cavities that need insulation at a later time – like garages.

What Blown-In Insulation is Made of

There are many materials that can be used to make blown-in insulation. A common option is loose-fill fiberglass. If this is the case, the materials are created with glass that’s spun or blown into fibers. Other materials that may be used for blown-in insulation include:

  • Styrofoam pellets
  • Cellulose material
  • Rock wool

If you go with blown-in insulation made of cellulose material, it’s typically made from wood-based products such as cardboard and recycled newspapers. However, it’s usually treated with boric acid and other compounds to make it resistant to mold, fire, and pests. It’s then placed in tightly-packed bags or bales.

Equipment Needed for Installation of Blown-In Insulation

The application or installation of blown-in insulation into drywalled garage walls is done with a mechanical blower or hopper. It’s designed to churn the blown-in insulation material with paddles. What this does is loosen it up and allow it to mix with air. You’ll then be able to blow nice, fluffy, easy-to-manage-and-control insulation through a hose in the desired location.

These machines are usually on the expensive side, so many homeowners looking to apply blown-in insulation normally rent one from a local hardware or home improvement store or centre. This can make the cost of purchasing the blown-in insulation materials more affordable since rental fees are often reasonable. Another option is to hire a professional contractor to insulate your garage’s wall. Doing so means they’ll bring everything necessary and you’ll just pay whatever the fee is for this service.

How Blown-In Insulation Will Be Installed in a Dry-walled Garage

Let’s assume you prefer to tackle this job yourself. In order to apply or “install” blown-in insulation in a dry-walled garage, there are three basic steps you’ll need to take.

Drill holes in the wall: The first step with blown-in insulation installation is to drill holes in your garage’s walls. With existing, closed-up walls in a garage, the holes are drilled about a foot down from the ceiling and about 3 feet up from the floor. Typically, two holes will need to be drilled per wall cavity that’s being insulated. These holes can be safely drilled right through drywall or plaster. Another way to go about drilling the holes is to place a series of holes horizontally through the drywall. If go with this option, center the holes between each wall stud to ensure you get optimal application. If need be, use a stud finder to locate studs in your garage wall. The recommended size for the drill holes is about 2 inches each. This is because the nozzle on the hopper is 1-2 inches in diameter, so making the holes 2 inches ensures the nozzle will fit.

Install the Insulation: The insulation blower or hopper is then used to force the preferred blown-in insulation material into the various wall cavities in the garage. As for the proper technique if you’re not having a professional do it for you, take the steps outlined below.

  • Thread the blower hose into the first hole you intend to use for application.
  • Form a seal by wrapping a rag around the hose and its nozzle and where it fits against the wall.
  • Have a friend turn on the blower as you hold onto the hose.
  • Gently pull the hose back as the cavity fills.
  • Continue to fill a hole until you feel resistance.
  • Have your friend turn off the blower.
  • Repeat the application process for each hole that was drilled in your garage walls.

Repair the Drill Holes: Plastic plugs are typically used to fill up the holes that were drilled to blow the insulation into your garage’s walls. They can then be painted over so they match the rest of your garage walls. Another possibility is to apply light plaster over the plugs if you’ll be repainting your garage walls entirely; or you can just plaster them over without plugs if you prefer and apply paint.