Do I need moisture resistant drywall in garage?

Author: Asia Murray II  |  Last update: Thursday, August 14, 2025

Choosing mold-resistant drywall for your garage can mitigate these risks, creating a safer storage environment for your belongings and a healthier overall home. This type of drywall withstands the rigors of garage conditions, from fluctuating temperatures to high humidity levels, preventing mold formation.

What kind of drywall to use in a garage?

In the US, IRC table R302. 6 requires 1/2 gypsum board on the garage side of walls shared with the residence or an attic. That would be regular drywall, not type x unless the local code has an amendment requiring it. The ceiling of a garage with habitable rooms above needs to have 5/8'' type x gypsum board.

Is moisture resistant drywall required by code?

To address these concerns, building codes often specify several key requirements for wet areas. These typically include: Use of moisture-resistant (MR) or mold-resistant drywall in wet areas. Proper sealing of joints and penetrations to prevent water intrusion.

Do I need a vapor barrier in my garage walls?

YOU NEED A VAPOR BARRIER. Vapor barriers are needed when there is a temperature difference between an outside area and an inside area. When hot meets cold, condensation occurs. Insulation will prevent the hot and cold from mixing but the vapor barrier is going to block the warm moist air out of your insulation.

Where is moisture resistant drywall needed?

Areas that experience high moisture levels or excessive humidity due to appliances, fixtures, or environmental conditions can benefit from mold-resistant drywall. Consider using mold-resistant drywall in kitchens, bathrooms, laundry rooms, mudrooms, and similar spaces where moisture is constantly present.

Why Don't Builders Finish Garage Walls?

Where do you use moisture resistant gypsum board?

It makes moisture-resistant boards such as Glasroc® H an excellent option, both for indoor and outdoor usage. In addition, our Aqualine® range is excellent for your bathrooms, toilets, kitchen, or other areas susceptible to moisture.

Can you use mold resistant drywall everywhere?

Not necessarily. While you can use mold-resistant drywall anywhere you would use traditional drywall, this is a product which is specifically going to benefit the homeowner in places where moisture will be present. Of course, that list starts with the bathroom.

Can drywall be used in an unheated garage?

Yes. The biggest thing to worry about is moisture, not heat. If there are large swings in temperature, moisture could form inside your walls and form mold or rot.

Will insulating an unheated garage cause mildew?

Insulating an unheated garage alone may not necessarily cause mildew, but the risk of mildew increases if there isn't proper ventilation. Insulation can trap moisture in the garage, especially in humid climates, creating a perfect environment for mildew growth.

When not to use vapor barrier?

Don't: Put Vapor Barriers on the Bottom of the Floor Joist in the Crawl Space. Because vapor barriers are good at retaining moisture, putting plastic sheeting on the joists can cause moisture to build up under the floor.

Does drywall in a garage need to be fire rated?

A: First, fire-rated systems are only required if the garage shares a wall or a ceiling with the home. If you are doing repairs in the garage you should replace with like materials, but remember it is the wall system that is fire rated not the product itself.

How much moisture is OK in drywall?

The real question is not whether your drywall is dry but whether the moisture level it contains is safe and appropriate. An acceptable level of moisture content is between 5% and 12%. Even a higher level may not spell disaster if not confined to a small area.

Where is greenboard required?

Green board is highly efficient in bathrooms and kitchens, where moisture is frequently in the air, but it is not the drywall that should be set behind tile in your shower or any other areas where it can come in direct contact with water.

Does garage drywall need to be moisture resistant?

Additionally, garages often double as storage areas for items that might absorb moisture, further exacerbating the problem. Choosing mold-resistant drywall for your garage can mitigate these risks, creating a safer storage environment for your belongings and a healthier overall home.

What are good walls for garage?

Several Wall Choices
  • Drywall. The low cost and minimal effort required to install it make drywall a common material for garage walls. ...
  • Plywood. Plywood is another low-priced choice that is both sturdy and long-lasting. ...
  • Metal Panels. ...
  • PVC Panels. ...
  • Slatwall Systems. ...
  • Veneer Of Brick Or Stone. ...
  • Insulated Panels. ...
  • Fiber Cement Boards.

Do garage walls need 5 8 drywall?

Walls between the residence and the attached garage, or ceilings between the garage and an attic space, must have at least 1/2-inch (12.7 mm) gypsum board on the garage side. If a habitable room is above the garage, the ceiling must be at least 5/8-inch (15.9 mm) Type X gypsum board on the garage side.

Do I need a vapor barrier for garage walls?

Step 3: Follow with a vapor barrier

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.

Should I insulate my unheated attached garage?

If you're simply storing your car in the garage, which is the intended purpose, you don't need insulation. However, if you plan to use your garage like an extension of your home, as many homeowners do, adding insulation can definitely be a worthwhile upgrade.

How much does it cost to insulate a 24x24 garage?

The cost to insulate a 24' x 24' garage is $3,000 - $8,000. Garage size influences the cost of insulation. The 24'x24' garage will house 2 cars and some extra space for other purposes. The average cost to insulate a 24x24' garage with spray foam is $6,000.

What type of drywall should I use in my garage?

Use Type X fire-resistant drywall for garages, as well as stairwells and areas near furnaces. While not totally impervious to fire, Type X drywall is designed to provide enhanced resistance to fire compared to basic fire-resistant drywall. Type X drywall tends to be thicker than other types.

What is the best wall covering for an unheated garage?

Plywood, MDF, or OSB is the best material for building garage walls because it is both inexpensive and easy to work with. They may be attached to the studs with frame screws and, unlike drywall, don't necessitate any finishing touches.

Do I need a permit to drywall my garage?

You'll likely need a permit since this project may require soil grading to avoid drainage issues. Repairing your floor may be more cost-efficient than replacing it if grading is necessary. No permit may be required to hang drywall on exposed wooden wall studs in your garage.

Where do I need moisture resistant drywall?

Space prone to moisture such as bathrooms and laundry rooms are also typically most prone to mold – which can be disastrous and costly to the structure of your home. Walls and ceilings in these spaces that are often damp due to humidity or splashing are suitable for mold-resistant drywall.

Why is the green board being phased out?

phasing out greenboard

This relatively new addition to the drywall market is gradually replacing green board because it's suited to the same tasks but even more water- and moisture-resistant than green board. Paperless drywall consists of a water-resistant gypsum core and a fiberglass (rather than paper) backing.

How to make regular drywall moisture resistant?

How to Waterproof Drywall. To prevent costly and time-consuming repairs from water damage and improve the water resistance of drywall, there are two options you can choose from: You can apply a waterproofing primer to standard drywall, or you can buy a water-resistant version of drywall from a local retailer.

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