What Kind of Drywall for Bathroom? Choosing the Right Moisture-Resistant Drywall
Bathrooms are unique spaces, constantly exposed to moisture from showers, baths, and general humidity. This makes selecting the right drywall crucial for preventing damage and ensuring longevity. Using standard drywall in a bathroom is a recipe for mold, mildew, and eventual structural issues. Instead, you need moisture-resistant drywall, often called moisture-resistant drywall (MR) or water-resistant drywall (WR). But even within these categories, there are choices to make. Let's dive in.
What is the Difference Between Regular Drywall and Moisture-Resistant Drywall?
Standard drywall (also known as gypsum board) is made of gypsum core sandwiched between paper facings. Moisture-resistant drywall uses a similar core, but the paper facing is treated with a water-resistant coating. This coating helps to repel moisture, slowing down absorption and reducing the risk of damage. While it won't stop water completely, it significantly increases the lifespan of the drywall in a humid environment.
What Type of Moisture-Resistant Drywall Should I Use?
The most common types of moisture-resistant drywall are:
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Moisture-Resistant (MR) Drywall: This is the standard choice for most bathroom applications. It offers better moisture resistance than standard drywall but isn't fully waterproof. It's suitable for areas with moderate humidity and splashing but should be combined with proper ventilation to minimize moisture buildup.
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Water-Resistant (WR) Drywall: This type provides a higher level of protection than MR drywall. It features a more robust water-resistant coating and is a better option for areas with higher humidity or direct water exposure, such as shower surrounds (though tiling is usually still recommended).
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Mold-Resistant Drywall: While not explicitly labeled as moisture-resistant, mold-resistant drywall contains additives that inhibit mold growth. This is a useful feature in bathrooms, but it's crucial to remember that it doesn't replace the need for proper ventilation and moisture-resistant facing. It's often a good idea to combine a mold-resistant option with a moisture-resistant one.
Is Cement Board Necessary in a Bathroom?
Cement board is a different material altogether, often used as a substrate behind tile in showers or other areas with direct water contact. While it’s exceptionally water-resistant, it's more expensive and more difficult to work with than drywall. Generally, cement board is recommended for shower surrounds where direct water contact is expected, not necessarily for the entire bathroom. You’ll typically use moisture-resistant drywall for the rest of the bathroom walls and then cement board specifically in high-moisture areas.
Should I Use Moisture-Resistant Drywall Behind a Shower?
While moisture-resistant drywall can be used in areas near a shower, using it directly behind a shower is generally discouraged by professionals. The constant stream of water from a shower will eventually compromise even the most water-resistant drywall. Cement board, coupled with proper waterproofing membranes, is the preferred choice in this location.
How Do I Install Moisture-Resistant Drywall?
The installation process is generally the same as for standard drywall, though extra care should be taken to ensure proper sealing of joints and seams to further prevent moisture penetration. Use moisture-resistant tape and compound designed for these applications.
What are the Costs Associated with Different Types of Drywall?
Moisture-resistant drywall typically costs slightly more than standard drywall, while cement board is significantly more expensive. The additional cost of MR or WR drywall is a small price to pay for preventing significantly more costly repairs down the line due to water damage and mold.
Remember, proper ventilation is key to preventing moisture problems in your bathroom, regardless of the type of drywall you choose. A well-ventilated bathroom will significantly extend the lifespan of your drywall and reduce the chances of mold and mildew growth. Consult with a building professional to determine the best type of drywall for your specific bathroom project.
