Can Drywall Be Used Outside? All You Need To Know!

Most people think of Drywall as an interior wall covering only, but can it be used outside too?
We all know that Drywall does not do well with moisture or water in general, so how would you be able to use Drywall outside?  Let’s find out.

A drywall that is sealed can technically be used outside. It’s better to go for moisture-resistant Drywall and seal it for maximum protection. In ideal conditions and with regular maintenance, Drywall can last for up to 30 years outside. In Humid areas and bad conditions, you might have to replace it after 1 year. 

When it comes to interior wall-covering materials, Drywall is certainly on top of the list. However, things are obviously different when it comes to the outside. You can say that using Drywall is possible. However, the answer is not that simple. 

Can You Use Drywall For Exterior?

Drywall (especially regular Drywall) is known to be a porous material. Even a little moisture would seep immediately right through it. However, that doesn’t mean you should give up on the idea of using this wonderful material outside.

Fortunately, by sealing them, you can make them “moisture resistant” and therefore useable outside. Or you can also, as an alternative, simply invest in moisture-resistant Drywall. 

Sealing would obviously be much cheaper however it might not give you the best result as a moisture-resistant Drywall would. 

The best would be to go for a moisture-resistant Drywall (known as Greenbaord Drywall) and seal it for maximum protection. This is especially crucial when you decide to use it in areas like the basement, bathroom, or areas with excessive water.

How To Seal Drywall For Outside Usage?

Sealing Drywall is fairly easy as adding sealant directly over the Drywall or mud for extra protection. You can apply the sealant whenever you want. However, it’s highly advised to do it when you hang Drywall. Sealing it later might be a bit risky, especially if you live in an area where moisture is constantly present. 

How To Use Drywall Outside?

Before Drywalling an exterior wall, you’ll need to consider a few things.

To give you a better perspective, below, we have provided a complete step-by-step guide explaining how to install Drywall outside:

Step #1 Prepare the Exterior Wall

As always, good preparation is crucial to any project, and knowing what needs to be done before you start hanging your Drywall can make a huge difference in the long run. You can skip this step if you want to install the Drywall over uncovered studs. In that scenario, you don’t need to do any additional work. Alternatively, if you’re planning on hanging your Drywall over stucco, block, cement, or flat surface, you would need to prepare the exterior wall. 

You can use 1×4 studs and install them on the wall. These studs will be used to attach your Drywall to the wall. It would be best to use high-performance construction adhesive to frame the studs. Before going any further, make sure the adhesive is completely dried out.

Step #2 Install a Vapor Barrier

Because of the potential concern with humidity and moisture, you should use a vapor barrier while hanging Drywall outside. You don’t have to invest a lot of money. You can use any plastic sheet and fit it over the 1×4 suds. 

The plastic sheet will act as a perfect vapor barrier between your Drywall and the exterior wall. Tack the plastic sheet from one corner of the wall and spread it out sideways. Don’t forget to staple the plastic sheet with the studs.

Step #3 Hang the Drywall

Once you have attached the vapor barrier, you can hang the Drywall. Instead of the top corner, you should start from the bottom. From one side, start attaching Drywall sheets to 1×4 studs. You should use 1/2-inch Drywall screws to fasten your sheets. If you want to know what type of screws you need for an outside project, this article would greatly help.

If you are required to cut a Drywall sheet, mark the section using a chalk line and run a utility knife over that specific section. Afterward, stand up your sheet and hit it carefully in the back. The panel will break cleanly, and you can continue with the installation process. 

Step #4 Apply Drywall Mud and Tape

For a better finish, you’ll need to smooth out Drywall seams. For this approach, you’ll need to use joint compound and Drywall tape. Apply as much joint compound as needed and use Drywall tape to cover it. You should use a towel to press the tape properly into the joint compound.

Once you put on the Drywall tape, you’ll need to apply another layer to the joint compound to eliminate imperfections and gaps. Repeat this step to finish all seams. To cover up the screw holes, you’ll only need to use the joint compound.

Don’t forget that if you’re using Drywall compound over Plywood, it might not stick. If you want to make sure that it does, read this article.

Step #5 Sand Down the Drywall

Wait for the Drywall compound to dry. Once done, you’ll need to sand down the Drywall to get a smooth finish. You can attach sandpaper to a wood block and sand all screw holes and seams. Afterward, get a damp cloth to remove dust from the Drywall sheet. 

Step #6 Sealing the Drywall

To Drywall an exterior wall, this step is extremely important. You must seal the Drywall to protect it from moisture and mold. Otherwise, your Drywall will break apart after some heavy rain. The best way to seal Drywall is by using a waterproof primer.

There are different types of primers available out there. Using a latex- or oil-based primer that is also waterproof is recommended. While a primer will protect your Drywall from moisture, it will also prevent mildew and mold growth.

If you also want to paint your Drywall, you should apply at least two coats of exterior paint. Keep in mind that primer should be used after painting the Drywall. On painted Drywall, you can use around 2 coats of waterproof primer to protect it from the weather.

Where Should You Use Drywalls Outside?

You can Drywall any outdoor area that is enclosed by a roof. This is because even if you use moisture-resistant Drywall, humidity and moisture will weaken, causing it to break apart with time.

If you want to Drywall an area not enclosed by a roof, it is ideal to use a cement board Drywall. This type of sheetrock is definitely more expensive. However, it provides unbeatable resistance to moisture, mold, and mildew. 

Where Should You Not Use The Drywall Outside?

The biggest problem with Drywalling an outdoor area is that you cannot control the environmental factors, such as air movement, humidity, and temperature. These factors directly influence how long it takes for Drywall to dry. 

So, if you live in a high humidity area, It will take much longer to dry, and the longer your wall takes to dry, the more vulnerable it is to cracking, mold growth, failure, and more.

How Long Do Drywalls Last If Used Outside?

Drywall is obviously not the strongest wall-covering material out there, but it can be long-lasting in ideal conditions. 

The average life span of Drywall is around 70 years, but this is when installed indoors and also in ideal conditions. 

If you are using your Drywall outside, the lifespan decreases by almost half. So, with ideal conditions and regular maintenance, outside Drywalls can last for up to 30 years. However, if you live in an area with high humidity and excessive rain, your Drywall might not even last for a single year – especially if you are using regular Drywall.


Can Moisture-resistant Drywall Be Used Outside?

The green board is not designed to be used outside. For outside, you should go for cement board Drywall or purple board Drywall. Cement is the most durable and most suitable Drywall type available out there. It is also the most expensive type on the market.

Can Drywall Be Used As Sheathing?

Yes, you can use Drywall as sheathing. s Drywall is made of gypsum – a non-combustible material. It is common practice to use this material as sheathing. For this approach, your best bet is yellow Drywall. It can be used in both residential and commercial use.

Is Drywall Mold Resistant?

Regular Drywall or green board Drywall is not mold-resistant. The purple board, the blue board, and the cement board are the best types of Drywall that prevent mold growth and survival.

Recent Posts