Code for Drywall in a Garage: A Comprehensive Guide
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What Is Code for Drywall in a Garage?
Are you planning a new garage or even thinking of a major remodel of the existing one? Great! But before you start the work, make sure that you have a “building permit” and know the Code for Drywall in a Garage.
The building permit is granted by the local building authority and the Garage Drywall Code is an important aspect of it. Building Codes can differ from state to state and sometimes even from county to county.
Fortunately, all of them follow the basic Garage Drywall Code laid out by International Residential Code (IRC), all across the US, in principle.
The relevant IRC code for drywall in a garage is summarized as under:
- Separation from the residence and attics: Not less than ½-inch gypsum board or equivalent applied to the garage side
- Separation from all habitable rooms above the garage: Not less than 5⁄8 -inch Type X gypsum board or equivalent
- Structure(s) supporting floor-ceiling assemblies used for separation: Not less than ½-inch gypsum board or equivalent
- Garages located less than 3 feet (914 mm) from a dwelling unit: Not less than ½-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area
For a detached garage, use drywall or an alternative to drywall, as a detached garage is not covered by any code for drywall in a garage.
The 2021 International Residential Code (IRC)
For those of you who would like all the references, Section R302.6 of The 2021 International Residential Code (IRC) is relevant to the Dwelling-Garage Fire Separation.
R302.6 Dwelling Garage Fire Separation (applies to adjoining Garage Walls & Ceilings) states that
The garage shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. Attachment of gypsum board shall comply with Table 702.3.5. The wall separation provisions of Table 302.6 shall not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.
Table R302.6
| Separation | Material |
| From the residence and attics | Not less than ½-inch gypsum board or equivalent applied to the garage side |
| From all habitable rooms above the garage | Not less than 5⁄8 -inch Type X gypsum board or equivalent |
| Structure(s) supporting floor-ceiling assemblies used for separation required by this section | Not less than ½-inch gypsum board or equivalent |
| Garages located less than 3 feet (914 mm) from a dwelling unit on the same lot | Not less than ½-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area |
The local building code for use of drywall in a garage is usually an exact copy of the above IRC code. Some local authorities may add to the above code for the sake of more clarity or making the code more stringent in their jurisdiction.
But no local building code will compromise on the IRC Code and make it less stringent.
What Does the IRC Cover?
The IRC contains coverage for all components of a house or townhouse, including structural components, fireplaces and chimneys, thermal insulation, mechanical systems, fuel gas systems, plumbing systems and electrical systems.
2021 IRC
At times there is a confusion between IRC and IBC. To clarify:
The International Residential Code (IRC) is essentially a subset of International Building Code (IBC). The scope of IRC is limited to “all components of a house or townhouse“. whereas the scope of IBC covers all types of buildings, such as shopping malls, offices, factories etc.
The International Building Code (IBC) is the foundation of the complete Family of International Codes®. It is an essential tool to preserve public health and safety that provides safeguards from hazards associated with the built environment.
The International Building Code
What Is the Latest Version of the IRC Code?
You have to be quite careful when referring to the information from the International Residential Code (IRC) that you pick up from a blog on the internet. Quite often a blog may refer to an older version of IRC.
Click on the link below to buy the spiral-bound latest version of the 2021 IRC Code Book:
The latest version of 2021 IRC was updated and made available online in November 2021.
Does Drywall in the Garage Need to Be Fire Rated?
IRC does not mention the term “Fire Rated“, mainly because, though gypsum is a solid powdery substance, it is actually 50% water (by volume) in crystalline form. This unique composition makes gypsum fire resistant.
The temperature of the gypsum will not go beyond 212°F (100°C) till all the water has evaporated. And even after that gypsum will not catch fire.
In case you have habitable rooms above the garage, then by code, you should use 5⁄8 -inch Type X gypsum board or equivalent.
I recommend that you use Sheetrock Brand Firecode Core. The original 5/8 in. (15.9 mm) Type X panels are suitable for interior wall and ceiling applications as it has a fire-resistant gypsum core and provides additional fire resistance over regular panels.
Please do keep in mind that IRC rules and the interpretation of those rules may differ across municipal bodies. So please do check with your local body. This post is only to be used as a guideline.
FAQ
Do garages need to be drywalled?
Use of drywall is recommended but not mandated by Section R302.6 of the 2021 IRC. The section, in every situation, states that an “equivalent” is also acceptable.
Do you need ⅝ “ drywall in garage?
According to Section R302.6 of the 2021 IRC:
⅝” thick fire-resistant Type X drywall or equivalent is required only on garage ceilings that have habitable space above them.
½” thick fire-resistant drywall or equivalent is required for walls adjacent to the living space or ceilings for non-habitable attics.
Should I use ⅝” or ½” drywall in my garage?
As per the garage drywall code of IRC, ⅝” thick fire-resistant Type X drywall or equivalent is required only on garage ceilings that have habitable space above them.
In other sections the garage drywall code of IRC permits you to use ½” thick fire-resistant drywall or equivalent.
However, unless the budget is a limiting factor, using ⅝” thick fire-resistant Type X drywall will increase both fire safety and overall sturdiness of the construction.
Thank you very much for reading the post. I do hope you found it informative and useful.
