Drywall can significantly affect how your home looks and functions. You’ve probably come across purple and green drywall as popular choices, and each comes with its own set of advantages and disadvantages. Knowing which one is a better fit for your project can save you time and hassle and help your home stay mold-free and resistant to fire and scratches. In this article, I’ll explain the differences between the two so you can pick the one that works best for your home.
What Is Drywall?
Drywall, also known as wallboard, gypsum wallboard, sheetrock, or plasterboard, is a construction material for interior walls and ceilings. It consists of two panels with a core of gypsum plaster between them. Builders have largely replaced the traditional plaster and lath method with drywall because you can install it easily and it’s more cost-effective.
Manufacturers create the gypsum core from a gray sulfate mineral composed of calcium sulfate dihydrate in crystalline form. They crush natural or synthetic gypsum rocks into powder, then heat or oxidize the material. After calcining the gypsum, they mix it with water and other minerals to form a thick paste or slurry. They then pour this mixture between two sheets of paper and feed it through a board machine to produce the final product.
Drywall comes in various sizes and thicknesses to meet different construction needs. It typically has a standard width of 48 inches, with lengths ranging from 8 to 14 feet. When it comes to thickness, you can usually find 1/4 inch, 1/2 inch, and 5/8 inch options.
Purple Drywall Features
Purple drywall, also known as mold-resistant drywall, is manufactured by Gold Bond Building Products. This type of drywall offers several advantages over standard options.
Purple drywall resists mold and mildew growth, making it an excellent choice for areas with high humidity or moisture exposure. This feature helps maintain a healthy indoor environment and saves homeowners money on future remediation efforts. Beyond its mold-resistant properties, some purple drywall products resist dents, scratches, and scuffs. This added durability is especially useful in high-traffic areas or places where walls might experience more wear and tear.
Many purple drywall products contain crystallized gypsum, which provides fire resistance. PURPLE® XP® drywall resists fire and meets safety and fire-resistant standards. Gold Bond Building Products manufactures a 5/8″ Type X gypsum wallboard, which is 5/8″ thick and adheres to ASTM Standard C 1396. This standard requires the wallboard to meet specific fire-resistance criteria. To confirm compliance, they conduct tests using the ASTM E 119 method, the standard test for fire resistance in building materials.
Purple drywall often incorporates an engineered layer of material that enhances sound-dampening properties. This design reduces sound transfer between rooms and dissipates structural noise from floors and ceilings.
You can use purple drywall in various spaces, including kitchens, bathrooms, laundry rooms, and basements. It also works well as a tile backer board for backsplashes, offering a versatile solution for home renovation projects.
Green Drywall Features
Green drywall offers homeowners another popular option. Here are some key features and benefits of green drywall.
Manufacturers design green drywall with a thicker paperback and a wax-coated surface to enhance moisture resistance. While it’s not waterproof, this moisture resistance makes it a good choice for areas exposed to high humidity or occasional water contact. Green drywall typically costs less than purple drywall, making it appealing for homeowners on a budget. It’s also a valid option for large-scale projects where managing expenses is essential.
Several manufacturers, including Sheetrock, CertainTeed, and USG, produce green drywall. Its wide availability makes it easy to source and familiar to many contractors and DIY enthusiasts. Although it doesn’t offer the same level of mold resistance as purple drywall, green drywall still provides some protection against mold growth when combined with proper moisture management techniques.
Green drywall lacks inherent fire resistance. Homeowners should avoid using it in areas exposed to heat or prone to fire without applying additional fire-resistant treatments or materials. This type of drywall offers some noise reduction benefits but isn’t specifically designed for that purpose. Homeowners aiming to improve sound insulation with green drywall may need to take extra steps, such as applying a noise-proofing compound between layers of drywall.
To make green drywall more soundproof, apply green glue—a viscoelastic noise-proofing compound—between the layers of drywall. It can help inhibit the vibrations traveling through floors, ceilings, or walls.
Cost Comparison
According to Angi, the standard price of purple drywall ranges from $15 to $60 per panel, while green drywall costs around $14 to $18 per panel. Installing drywall costs between $1.50 and $3 per square foot, covering both materials and labor. The price you’ll pay can vary depending on things like the thickness, type of drywall, and other details. Several factors come into play regarding the final cost, from the kind of drywall you choose to the finish you want. It depends on the specific product brand and any additional features or treatments required for the installation.
Water Resistance: Purple Drywall Wins
Both purple and green drywall offer water-resistant properties, but some key differences exist. Purple drywall provides high water resistance and works well in wet areas, such as bathrooms, including spots that may come into direct contact with water splashes.
On the other hand, green drywall resists moisture but isn’t waterproof. It suits damp or moist areas but shouldn’t go in locations where it will face direct and prolonged contact with water. Remember, neither type of drywall is entirely waterproof, and both can suffer damage when exposed to water for extended periods.
Where Can I Use Purple Drywall?
Use purple drywall in:
- Bathrooms
- Kitchens
- Laundry rooms
- Basements
- Areas prone to high humidity
- Spaces requiring enhanced fire resistance
- Rooms where sound insulation is a priority
Where Can You Use Green Drywall?
Use green drywall for:
- Areas with moderate moisture exposure
- Kitchens (away from direct water sources)
- Laundry rooms
- Basements (with proper moisture control)
- General living spaces in humid climates
Installation Tips for Purple and Green Drywall
When you install either purple or green drywall, follow recommended techniques and guidelines to maximize the effectiveness of these materials. Here are some installation tips for a successful project.
1. Prepare the Surface
Before you start the installation process, prepare the surface. The framing should be level, and all wiring and plumbing installations should be complete. Also, inspect the area for any signs of moisture or water damage that you need to address before installing the drywall. This step will help prevent future issues.
2. Cut the Drywall
Make accurate measurements and precise cuts for a professional finish. Use a utility knife to score the drywall along a straightedge, then snap the board along the scored line. For intricate cuts, such as those around electrical outlets or plumbing fixtures, use a keyhole or drywall saw.
3. Fasten the Drywall
Fasten the panels to the wall studs using appropriate drywall screws or nails. Space the screws about 12 inches apart along the edges and 16 inches apart in the middle sections of the panel. Set the screws slightly below the surface of the drywall without breaking the paper facing. Don’t overdrive screws or nails.
4. Seal the Joints
To seal the joints between drywall panels, apply joint tape and joint compound (also known as mud). Begin by applying a thin layer of joint compound over the joint with a taping knife. Next, embed the joint tape into the compound, centering it over the joint. Apply additional coats of compound, feathering the edges to create a smooth, seamless surface. After it dries, sand the compound until smooth.
5. Add Moisture Protection
In areas prone to moisture, such as bathrooms or basements, apply a waterproofing sealer or membrane over the drywall before painting or tiling. This extra layer of protection helps prevent water damage and mold growth, extending the life and appearance of the drywall.
6. Consider Ventilation
Provide proper ventilation in areas where you use moisture-resistant drywall. Good airflow helps maintain a dry environment and reduces the risk of growing mold and mildew. I recommend installing exhaust fans in bathrooms and kitchens to lower this risk.
Common Mistakes To Avoid When Installing Drywall
Even with the best materials, mistakes during installation lead to inferior results and potential issues in the future. I recommend avoiding these common pitfalls when working with purple and green drywall.
One of the most common mistakes is skipping the primer before applying paint or wallpaper. Primer helps with adhesion, ensuring a long-lasting finish and sealing the surface to create a uniform appearance.
Improperly sealed joints create visible seams and cracks over time. Apply joint tape and all necessary coats of joint compound correctly. Allow each coat to dry fully before sanding and applying the next layer.
Final Thoughts About Purple Vs. Green Drywall
When choosing between purple and green drywall, homeowners should consider their needs, budget, and the installation location. Purple drywall offers superior mold resistance, fire resistance, and sound-dampening properties, making it an excellent choice for moisture-prone areas, but it is more expensive.
Green drywall is more budget-friendly and may suffice for many locations in your home. Ultimately, decide between purple and green drywall by balancing performance requirements with cost considerations. By carefully evaluating the needs of each space in your home, you can make an informed choice on which drywall will offer the best protection for your home.
