When it comes to the shower area, choosing the right material is extremely important. It is an area that is directly exposed to water, so every choice you make will impact the functionality and cost in the long run.
Today, we will answer one of the most frequently asked questions about shower area drywall:
Is it safe to use Greenboard drywall in a shower?
Greenboard drywall is highly recommended for bathrooms and kitchens because it is water-resistant. However, it is not the best option for the shower because it is not water-proof enough for any area that comes in direct contact with water.
Greenboard is excellent for some places in the bathroom, but not the shower.
The confusion arises because water-resistant and water-proof are sometimes misunderstood. While a water-resistant material is excellent for areas with a lot of moisture in the air, it won’t hold up against direct contact with water.
So, for the shower area or bathtub, greenboard drywall may not be your best option. However, it may not be a code violation, and in many regions, manufacturers recommend it for the shower but with proper treatment to make it water-proof.
Before we move on to alternative options, let’s make sure we understand the difference between water-proof and water-resistant
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Water-proof vs. Water-resistant
Water-resistant means that the material can prevent penetration of water to a certain degree, which means it is good for damp areas where the air has a lot of moisture. Such material can do a great job keeping the moisture in the air from penetrating through the surface. Water-proof means the material will prevent penetration of water even when submerged for a long time.
Greenboard drywall has the same gypsum core as regular drywall but is covered with a water-resistant paper. The paper keeps moisture from seeping in, and therefore, it is great for your basement, kitchen, or rest of the bathroom. For the shower, you need something that’s water-proof.
Water-proof Options
In most areas, the building code doesn’t prohibit the use of greenboard in the shower. Therefore, it’s quite commonly seen in older bathrooms. It is cheaper than most water-proof options, and you can make it water-proof with a coat of water-based urethane.
There are many brand name water-proofing coatings and paints that can be applied on greenboard to make it water-proof.
Cement board is a better alternative because it is water-proof. Additionally, cement board can be used in tiled flooring as well as walls.
The Verdict
As per IRC, water-resistant backing boards shouldn’t be used in a shower or bathtub compartment. The code prohibits its usage in any area with direct and prolonged exposure to water or areas with constant high humidity. The regulations may not apply to your location, but best practice is to go for an option that you won’t have to regret in the long run.
Related Questions
Can I water-proof drywall?
Yes, the drywall can be water-proofed by coating it with water-based urethane before installing it. Once installed, a second coat provides for better performance.
What is the best drywall to use in a bathroom?
Cement board is the perfect replacement for drywall for placing behind the tiles in wet areas of the bathroom. It’s durable, as well as moisture, mold, and rot-resistant.
What is the best waterproofing membrane for showers?
The liquid waterproofing membrane is perhaps the most popular. Available in paint form, it is super easy to apply.
Can I use purple drywall in a shower?
The characteristics of the purple drywall make it incredibly resistant to mildew, mold, and moisture, similar to the cement board. Also, it is fire resistant.