Drywall is a building material used to cover the interior of a structure. While installing drywall in garages isn't always necessary, doing so is a wise choice. If legal requirements do not affect your decision, weigh the benefits of installing drywall against the costs to determine whether installing drywall in your garage is the right choice for you.
Many building codes have specific requirements for drywall in garages, so check with your local building department to determine what regulations you must follow. Often, you must install drywall in a garage to limit the mobility of potential fires. People park cars and store flammable chemicals in garages, so most building departments require homeowners to install 5/8-inch drywall, which retards the progress of fires and helps protect the inhabited sections of a home.
If installing drywall is optional in your region, you still might benefit from covering the interior of your garage. Drywall will offer some soundproofing, meaning you can work in your garage without disturbing others. When installed over quality insulation materials, drywall helps you regulate the temperature of your garage. And installing drywall allows you to paint the interior of your garage, which looks better than having unfinished wood studs and drooping insulation.
Installing drywall and then performing one coat of drywall finishing, but no more, often results in a garage that has exposed portions of paper drywall tape. Over time, the paper yellows and peels away because it is exposed to humidity. If you do drywall your garage, perform all three coats of drywall finishing. First, embed paper drywall tape in joint compound over each seam between the boards of drywall. Second, cover all the paper tape with a thick coat of joint compound. Finally, sand the joint compound until it is smooth, and then apply a thin coat of compound to give the drywalled surfaces a polished look. At this point, you can leave the drywall alone, but priming and painting will improve the look of your garage even more.
Most garages receive 5/8-inch drywall, which often is sufficient for building codes. But also important is covering any gaps around garage door hardware, pipes, girders or other structural elements that leave space through which fire can travel. Install full pieces of drywall to cover the majority of your garage's interior. For small gaps, use foam insulation or whatever material your local building code requires to limit a fire's mobility.