How to Insulate a Garage Ceiling That’s Already Drywalled

You may think that you need to remove your existing drywall to insulate your garage’s ceiling. That isn’t the case! There are a few options available for insulating a ceiling that’s already finished. Whichever option you choose, there are multiple ways to move forward with insulating your garage ceiling!

To insulate your garage ceiling when that’s already drywalled, use cellulose insulation or spray foam insulation through holes in the drywall. You won’t be able to install rigid or fiberglass insulation without removing the drywall. 

There are options that you can pursue without removing drywall. Here, we’ll take a look at what your options are if you can install your insulation, and what the benefits of each of these options are. We’ll examine whether you should remove your drywall or leave it up, as well as whether this type of insulation is worth it after all!

Insulation Options When Drywall Is Already Up

There are many options for insulating your spaces, but most of these must be added before the drywall is installed. Rigid foam insulation and fiberglass sheets are great options to use before the installation of drywall. 

There are two main solutions for insulating your garage ceiling if the drywall is already up: cellulose insulation and spray foam insulation. Next, we’ll take a look at what these types of insulation are and which is best for you.

Cellulose Insulation

Cellulose is loose-fill insulation that is often blown into the space between the exterior wall and the drywall. This insulation is often used in walls that are already enclosed because it can move around wires, pipes, and other internal structures. It’s a less-messy alternative if you can’t remove the drywall to add sheets of fiberglass or similar insulation.

To install cellulose insulation, you have to make a hole in the drywall so you can access the space between the walls. It settles over time once it’s applied and is generally inexpensive compared to other types of insulation. 

Installing cellulose insulation requires the use of a special machine that can be rented from most tool shops. It can be difficult to use, but some shops will allow you to rent the machine for free if you purchase the material from them (The Spruce). 

Benefits of Cellulose Insulation

  • Can conform to most structures within the walls and ceiling
  • You don’t have to tear down drywall or reinstall it with this method
  • Settles over time so it’s perfect for walls that are already enclosed

Drawbacks of Cellulose Insulation

  • May sometimes create bare patches where it settles over time
  • Can soak up moisture
  • Special machine rental required
  • Expertise is a huge benefit

Spray Foam Insulation

Spray foam insulation is an expensive alternative to materials like cellulose, and it can easily be installed under the drywall in your garage’s ceiling. It is installed in a similar way as cellulose insulation, but it is much more expensive. Some may consider it overkill for a garage, but it is a viable option. 

Spray foam is so expensive in part because it comes in two parts. It’s a liquid material that comes with an iso and resin drum. These have to be mixed together during application through the use of a special spraying machine. 

Spray foam is best installed by a professional, as mixing these two materials may take some practice. 

There are two types of spray foam that you can choose: open-cell and closed-cell spray foam. Closed-cell foam is the higher-density option and often used as roofing foam, so it’s probably the type that you want in your garage ceiling (Icynene).

Benefits of Spray Foam Insulation

  • Can expand to between 40% and 100% of its original size to fill gaps
  • Water-resistant
  • Great for ceilings 

Drawbacks of Spray Foam Insulation

  • Extremely expensive compared to other insulation types
  • May need to be applied by a professional
  • May expand rapidly, so you have to be extremely careful when installing it if you choose to DIY

Benefits of Installing Insulation in Your Garage

There are several reasons why you might want to insulate your garage’s ceiling. Unfortunately, we have to talk about why it probably won’t help you out first. 

First of all, insulating your garage isn’t going to help keep your garage at the same temperature as your home. Even if it’s perfectly insulated on all sides, the door will still create a draft or energy leak. You might still need to use a heater in the winter or a fan in the summertime. 

However, insulating your garage can reduce these extreme temperature changes. It can also make heating the garage much easier in the winter. 

But insulation isn’t just used for temperature control. You can also use insulation to protect your valuables, keep pipes that run through the garage from breaking, and reduce noise. 

Should You Remove Your Drywall? 

Whether or not you choose to remove your garage’s drywall is entirely up to you. If you know how to install it yourself, it may only cost a few hundred dollars extra to rehang the drywall when you’re done with the insulation process. 

The good news? If you choose to tear out your drywall, you can choose less expensive insulation. Your insulation may also be more effective if you use fiberglass or rigid insulation instead.

However, you are going to spend a bit more to reinstall the drywall. If you can do it yourself, it’s going to be a lot more work but you may save a bit of money. Otherwise, you can easily use one of the methods explored above to insulate your garage without removing the drywall that’s already there.

Can You DIY Garage Ceiling Insulation? 

Generally, doing your garage ceiling insulation yourself shouldn’t be too much of a hassle, but there are some things you should consider before undertaking a project like this.

The first thing to note is that while you can install both cellulose and spray foam insulation yourself with the use of specialized equipment, it is not recommended that everyone do so. 

For one, the materials are often more expensive than the labor and materials cost from a professional company. Why is this? Most professional insulation technicians get discounts on their materials, so they aren’t overcharging as some retail companies will. It’s cost-effective in most cases to hire someone to insulate your garage ceiling.

Insulation materials are often dangerous to work with if you don’t know what you’re doing. While retail companies will rent you a blowing machine for installing cellulose insulation, for instance, you may have to do a lot of research to understand how to use it effectively.

To avoid the damage, mess, and hassle that can come with installing your insulation, we’d recommend hiring a professional service to do it for you. If you do choose to install your insulation yourself, be aware of the risks, and take extra care to understand how the materials work.

Insulating The Garage Ceiling Doesn’t Have to Be Painful

Installing insulation in your finished garage can be as easy or as difficult as you want to make it. However, there are different options for insulation depending on whether you want to remove the existing drywall or leave it where it is. Just because your garage is already drywalled doesn’t mean that you can’t add insulation!

Have you insulated your garage when the drywall was already up? Let us know what you used and why below in the comments! We love hearing personal victories on all these garage improvement projects!