Drywall is the process of installation and is the name most commonly used to refer to, Plasterboard, Wallboard, Gypsum board, or sometimes by their brand names of Sheetrock (from USG) and Toughrock (from Georgia Pacific). Although pros use many different types and names of drywall in both commercial and residential projects, there are five that are useful for DIYers tackling a variety of home improvement projects. Here's what you need to know about these different types of drywall and what to use them for in your home.
All types of drywall come in standard 4-foot by 8 foot-sheets. However, they also come in other dimensions. Most of the variation in size involves length; 8-, 10-, 12- and even 16-foot sheets are available. Longer sheets are often used to cover large areas and are usually used only by professionals. Many of these types of drywall also come in 54-inch width (4.5 feet). These are used for rooms with 9-foot ceilings. It’s not surprising that the price increase as you increase in length, for example, a 10-foot sheet might cost 25% more than an 8-foot sheet. Picking the right size and avoiding unnecessary joints is just one of several blunders you can avoid when hanging drywall.
Finally, some types of drywall, like Type X fire-resistant drywall, are available only with a 5/8-inch thickness. However, other types of drywall come in different thicknesses; the most common are 1/4 inch, 3/8 inch, 1/2 inch, and 5/8 inch. The most common thicknesses for general application are 3/8 inch and 1/2 inch. However, several decades ago, 1/2 inch became the industry standard. Quarter-inch drywall is often used to cover damaged plaster walls and also for curved areas because it bends easier than thicker drywall. Then the 1/4-inch-thick drywall can be double layered to get to the conventional 1/2 inch thickness to match the rest of the wall. Quarter-inch and 5/8-inch drywall tend to be slightly more expensive than 1/2 inch or 3/8 inch.
Regular or Blue Board
Regular (gray) drywall is the most common type of drywall and it’s the only kind many people are familiar with. All drywall has one thing as its core—gypsum, a common mineral found globally. In regular drywall and most other types as well, gypsum is sandwiched between two layers of paper. There is paper on the back (usually brown) and the face, which, in the case of regular drywall, is gray. Regular drywall can be used throughout a house and comes in a number of dimensions—the most common size is a 4-foot by 8-foot sheet. And, as the most common type of drywall, it is also the cheapest, selling for about $12 per 4-foot by 8-foot sheet, depending on where you live. Just getting started with a drywall project? Here are some of our best tips to help you install it right.
On the other hand, blue board is constructed a bit differently. Blue board still has the same gypsum interior, but the outside is coated in a blue paper, hence the name. This blue paper is designed to bond with a specific kind of plaster. This allows builders much more control over the final texture and smoothness of the walls after the plaster application. Blue board also doesn't require a three-day waiting period, as the entire project can be completed one step after another. After the blue board has been mounted, the installer can apply some tape and then plaster the joints with no joint compound needed. After that, the entire wall is covered with one or two thin layers of special plaster.
The benefit of using blue board is the strong absorption of the blue paper. Since the paper absorbs much better than normal drywall, the overall product is much smoother and evenly toned across the entire wall. The joints are not as obvious, and the final texture is incredibly smooth to both touch and sight. Since the blue paper is much more receptive to the application of paint versus the drywall mud, builders have a variety of choices for finishes and final looks for their blue board installation.
Green Board
Green drywall is a type of drywall that's mold-resistant and is used in applications where moisture can be an issue, so most commonly installed in bathrooms. To maximize the mold resistance, use mold-resistant drywall mud, aka joint compound. Green drywall generally costs about 20% more than regular drywall.
It is best to use green board or other water-resistant drywall in the large areas of bathrooms, kitchens, and other areas where the drywall may be subjected to lightly damp conditions, humidity, and the occasional minor splashes of water.
While standard drywall is the gray hue you are probably familiar with, some specialty drywall is known by its color, much like blue board. Green board is a term used for mold-resistant drywall that is common in bathrooms and other moisture-prone places. Green board has a treated core with no paper backing but has instead a special moisture-resistant coating. Green board is slightly more expensive than standard drywall and requires a specific mold-resistant joint compound.
Purple Board
Purple drywall resists moisture, mold, and mildew. In addition, Purple drywall also resists scratches, scuffs, and dents so it’s a good choice for high-traffic areas. Purple drywall is about 30% more expensive than regular drywall. Here is a collection of tips for preventing bathroom mold.
While all gypsum-based drywall is naturally fire-resistant, the Purple drywall is unique because it also resists moisture, mold, and mildew. In addition, some purple drywall also stands up to scratches, scuffs, dents, and noise and is another great choice to use in bathrooms, but it's much more forgiving than green board when it comes into contact with water. You can use purple drywall for the ceiling and/or upper walls of a shower, for example.
Fire-Resistant Board
All types of drywall are inherently fire resistant. However, there is a special type of drywall that has higher fire-resistance ratings than others. This drywall is known as Type X, and it’s thicker (5/8 inch instead of 1/2 inch or less). Type X drywall has glass fibers mixed into the gypsum to increase its resistance to fire. It is not fireproof, but most Type X drywall has a one-hour fire rating. Type X drywall is hung just like regular drywall and is usually required by building codes for the shared wall between the house and an attached garage.
Although no wallboard is totally fireproof, the mineral in drywall can't help but resist burning. Calcium sulfate dihydrate gypsum traps water molecules within its crystalline matrix. There it remains until exposed to heat higher than 176 degrees Fahrenheit. Typically one layer of Type X drywall promises 45 minutes to one hour of fire protection for the building constructed with this type of material.
Gypsum Board: Two (2) hour-rated walls have two (2) layers of 5/8" Type 'X' gypsum wallboard panels on each side of the steel studs. The "Fire Tape" product would be used as an alternative to conventional joint tape in specific systems when: 3.
Sound Dampening Board
Sound damping drywall is the same thickness as regular drywall (1/2 inch,) but it is layered. In between the front and back paper is a 1/4-inch layer of gypsum, followed by a membrane and then another 1/4-inch layer of gypsum. The layering effect increases the Sound Transmission Class (STC) and reduces noise transmission from one room to the another. Sound dampening drywall doesn’t require special tools or equipment to install and can be used in any room of the house. It is significantly pricier than regular drywall, however, costing about 400% more than regular drywall. If you're planning a construction project where noise control is important, you might be facing the choice between using multiple layers of standard drywall and buying very expensive “soundproofing drywall.” Does soundproofing drywall work and is it worth the cost? The short answer is Yes: soundproofing drywall works.
It took some time for the building industry to recognize drywall for what it is - an extremely versatile, inexpensive, and sustainable material that has overcome its initial reputation as a cheap substitute for plaster to become something an average person could use to build walls.