How to finish your garage

January 1, 1

This often-overlooked home reno can help you create usable space, get organized and protect your family and belongings

If you’re like most homeowners, you’ve probably got a running list of projects to tackle around the house. Floors, plumbing updates and windows and doors were the most common home improvements in 2019. Kitchens and bathrooms are almost always in the top 10, too. But, have you ever considered adding a garage renovation to the list?

It might seem like an odd part of the house to spend money on, but there are several reasons to consider making finishing the garage a priority project. These include:

  • Thermal protection for energy efficiency
  • Fire protection, especially when the garage is attached to the house
  • Adding usable living or hobby space
  • Organization—the garage is often a cluttered storage space
  • Moisture control to protect contents
  • Investment—finishing spaces almost always improves the resale value of a home

Whatever your reason, it’s important that you tackle a garage renovation properly, just as you would any other space, to ensure you’re being safe, efficient and getting the most benefit possible from your effort.

Getting Started

Generally, the approach to tackling a garage renovation is similar to other home renovations.  As with any other home improvement project, it makes sense to start with a plan.

Step 1: Make a plan

It’s one of those golden rules that time spent planning a home improvement project is a good investment. There are several questions to consider that will help guide you along the way, keep you focused, efficient, and make sure nothing gets overlooked.

  • First, how do you want to use the space? Are you adding living space or storage, or both?
  • What is currently in the garage? This is more about building materials, stud spacing, etc. than the contents of the space. Are the walls bare concrete, drywalled, or are there exposed studs?
  • With the intended purpose of the finished space in mind, what materials do you need for the project? Consider all surfaces, including walls, the ceiling, and the floor, and what is needed to finish them.
  • Do you need to make any electrical additions or improvements? Think about lighting and power sources that will improve the usability of the finished space.
  • What about plumbing? If it’s going to be a work or hobby space, do you need to install a utility sink? If it’s intended for extra living or entertaining space, maybe you want to include a wet bar?
  • What are your local code requirements? We know it’s tempting to skip this step, but the time and effort are worth it in the long run. Here’s what you should be investigating:
    • Are fire doors required?
    • Do interior and exterior walls need to be insulated?
    • What is the necessary fire-rating for separating walls?
    • What about HVAC? Be sure to consider the multi-use nature of the space. Is there a heat source for when it’s inhabited? If you’re still storing the car in the garage, what about venting?

With this information in hand, get necessary permits in place before you start any work. And it goes without saying, if after making your plan you realize there are elements you can’t manage on your own, hire professionals when needed.


Step 2: Start with insulation

Your insulation needs will differ between interior and exterior walls. The rule of thumb is to treat the garage as interior space by fully insulating the exterior walls and leaving the separating wall between the garage and the home uninsulated. However, if you have a detached garage with a block wall you have a few options. You could:

  • build out the frame and continue insulating with ROCKWOOL Comfortbatt®, or
  • insulate with ROCKWOOL Comfortboard using appropriate fasteners which can provide you with a semi-finished look by leaving the rigid insulation exposed, or
  • cover it with drywall for a finished look.

You might also wonder about insulating the pitch of the roof versus the rafters. What’s the best option? It all depends on what you want to do with the space. Insulating the rafters allows you to easily use the attic space as storage. And it can better control moisture to help prevent what you do store in that space from becoming damaged. However, if you had a living space above the garage, you would insulate with ROCKWOOL Safe’n’Sound® for continued fire resistance and to control sound for a more pleasant indoor experience for occupants.

Next, select the right product for your needs; most will find Comfortbatt® is an ideal choice (R14 in Canada or R13 or R15 in the US), assuming 2 x 4 wood studs, but Comfortbatt® comes in a range of R-values and thicknesses, depending on your location, the level of thermal resistance you want to achieve and the size of your studs, joists or rafters.

Regardless of the R-value and thickness, there are many benefits to using ROCKWOOL® Comfortbatt® in your garage. The thermal stone wool insulation is ideal for use in exterior walls, attics, and basements and provides consistent, comfortable indoor temperatures and energy savings throughout the year. On top of that:

  • Comfortbatt® offers excellent thermal performance
  • It is easy to install and simple to cut with a serrated blade to achieve an optimal fit around electrical wiring boxes, and pipes, and between studs and joists that are not standard width
  • Friction fit compresses on install then springs back to fill the stud completely to prevent gaps
  • It is dimensionally stable—it will stay firmly in place to provide energy savings over the life of the space
  • It is noncombustible, resisting fire up to 1,177˚C or 2,150˚F
  • It is water and moisture resistant; in a garage this is particularly useful as it is resistant to mold and mildew


Step 3: Follow with a vapor barrier

This step is commonly misunderstood, and therefore skipped, by homeowners when renovating. The primary function of a vapor barrier is moisture control. In the garage, like other spaces in the home, condensation results from moisture in the air. Excess condensation and humidity levels in your garage can damage your garage’s foundation and cause tools, vehicles, and cabinets to rust faster. This can happen in both hot and cold climates. Low winter temperatures, followed by the rising humidity of spring and early summer, make your garage and home vulnerable to excess moisture. Homes in areas with high humidity and occasional temperature drops will also experience garage condensation.

Combining a vapor barrier with Comfortbatt® insulation will further improve moisture control in the space as it’s water and moisture resistant.  It does not absorb moisture to maintain its insulating value. Additionally, insulating with ROCKWOOL Comfortbatt® stone wool insulation will help keep the garage temperature more stable. The product is moisture resistant and vapor permeable with high drying potential, so even if it is exposed to moisture or comes into contact with water, the insulation will dry out and retain its full R-value. Because of its inorganic composition, it’s also resistant to mold and mildew, so it’s a great choice for this application.

Step 4: Finish walls and ceiling

The materials you select will depend on the intended function of the space. For example, if you’re turning the garage into extra living space, install drywall and then prime and paint it for a quality finished look. Think about trim around doors and windows. If you’re finishing the space to make it more organized for storage, you may still want to consider drywall along with slats, shelves or cupboards. Today there are lots of organization systems available that are designed for easy installation by DIYers.


Step 5: Last but not least... Floors

Remember…the space you’re finishing is a garage; if you’re still planning on using it to store vehicles, do you need to consider drainage? Regardless, select a durable material that won’t absorb oil or other fluid leaks and is easy to clean. As with DIY storage solutions, there are so many incredible flooring options available today for garages that are both functional and stylish. Depending on your selection, you may want to hire a professional for installation or application. Whatever your choice, finish it all off with durable trim or baseboards.