Standard Drywall Panels
The 1/2-inch panel is the most common thickness and is generally utilized in single-layer applications on residential walls and ceilings. It can also be used in multilayer applications for improved sound control.
In 3/8-inch thickness, the panel has reduced weight and is usually applied in double layers in new construction. In remodeling, you can utilize the thinner panel over existing surfaces to create a fresh and flat surface.
The 1/4-inch panel is also useful as an overlay for walls and ceilings in remodeling projects. It bends easily to create archways and curved walls, although its bending radius is not as small as 1/4-inch flexible drywall. Refer to the chart on page 120 for minimum bending radii for a variety of panels.
1/4-inch flexible drywall
This specialty product is very useful for creating tight-radius archways and curves in walls and ceilings. The tapered-edge panel is 48 inches wide, and you can buy it in 8- and 10-foot lengths.
By utilizing panels that are 54 inches wide, you can apply drywall horizontally to walls that are up to 9 feet tall. Horizontal application produces a stronger wall. You'll find these wide panels in 1/2- and 5/8-inch thickness and in lengths of 8, 9, 10, 12, and 14 feet. Vertical application helps minimize hard-to-conceal butt joints (the junction of two untapered edges).
Building codes specify where you must use fire-resistant drywall -- furnace rooms and attached garages are typical examples. The typical panel chosen for these applications is 5/8 inch thick, and carries an X fire-resistance designation. At least one manufacturer makes a 1/2-inch panel with special additives in the gypsum core (designated C core) that improves its fire resistance above that provided by the 5/8-inch panel. Carefully check with your local building inspection department to ensure that your materials and construction methods comply with regulations.
Even when you don't need fire-resistant properties, 5/8-inch drywall is a great choice. In fact, it's your best choice for the highest quality results in a single-layer application throughout your home. The slightly thicker panels produce significant improvements in several important areas at only a modest price increase over 1/2-inch drywall. The thicker panes produce walls and ceilings that are flatter, more sag resistant, don't dent as easily, control sound better, and span wider framing.Specialty Panels
You can easily identify moisture-resistant drywall by its distinctive green, blue, or blue-green color. Some typical application areas include bathrooms and kitchen backsplashes. It accepts paint and wallpaper and serves as an acceptable base for ceramic and plastic wall tiles in areas that will not be wet for a prolonged time (walls other than a tub surround, for example). However, if you utilize it as a tile substrate, you should omit the installation of a vapor barrier behind the panel. The material is not waterproof and will not tolerate constant moisture or humidity.
Moisture-resistant panels are available in 1/2- and 5/8-inch thicknesses and also in fire-resistant panels: a 1/2-inch thickness with a C designation and 5/8-inch thickness rated X. The 48-inch-wide panels have tapered edges and are available in 8-, 10-, and 12-foot lengths.
For increased dent resistance, consider abuse-resistant panels. You can use them as an upgrade in virtually any room in the house. Likely locations include garages, recreation rooms, a child's room, high-traffic hallways, workshops, and hobby rooms.
The panels are available in 1/2-inch or 5/8-inch thickness with an X fire-resistance rating. The tapered-edge panels are 48 inches wide and available in 8-, 10-, and 12-foot lengths.
Sag-resistant ceiling panels
Ordinary drywall panels can deform under the weight of insulation or sag when softened by the application of texturing or finishing materials. One way to overcome these problems is to upgrade to 5/8-inch panels, but their weight can make installation difficult. Sag-resistant 1/2-inch-thick panels offer a solution without creating a weight problem. The tapered-edge panels are 48 inches wide and come in 8- and 12-foot lengths.
These panels are essentially standard drywall with a kraft-backed aluminum foil laminated to the back face, useful in cold climates. By installing the metal face against the framing in a single- or multilayer application (foil-backed for the base layer only), you create a vapor barrier that prevents the migration of moisture into wall or ceiling spaces.
The panel is not recommended as the base for ceramic or other tiles. You should also not use these panels in air-conditioned houses when the area has sustained heat and humidity, such as in the Southern Atlantic or Gulf Coast regions of the United States. Check with a mechanical engineer (heating/cooling specialist) if you have doubt about the installation of these panels in your climate zone.
Spaces with extreme conditions -- especially high moisture levels, such as an indoor hot tub or pool, sauna, or steam room -- demand special solutions. Consult a drywall supplier or mechanical engineer for material recommendations.
You should also consult an expert for advice in achieving high levels of noise reduction or fire resistance.
A special gypsum panel called blueboard is used as the base under veneer plaster applications, and redecorated panels are often used in factory-built housing such as mobile and modular homes. However, these products are outside the scope of this book.
Sound control and backerboards
Sound control board (Homasote 440 is one brand) is installed as the first course in a multilayer installation. The panel is manufactured from cellulose fiber and offers thermal insulation plus sound reduction when installed in floors and ceilings. The product is manufactured in thicknesses of 1/2, 5/8, and 3/4 inch.
Gypsum backerboard is available in several thicknesses, and is utilized as a substrate for installation of ceramic tile and stone on both walls and floors. You can score and snap gypsum backerboard just as you do with drywall panels.
As its name implies, cementious backerboard is a cement product that's reinforced with a fiberglass mesh. Cutting this product is more difficult than its gypsum cousin, but it can be more durable if subjected to water. You'll find this product in several thicknesses.
Both types of backerboard require special corrosion-resistant screws -- ordinary drywall screws are NOT recommended. Also make certain that you purchase fiberglass mesh tape that's compatible. The drywall variety of tape is not suitable.
- Artistic Drywall Styles & Elements
- Drywall Tools
- Framing Basics for Walls & Ceilings
- Drywall Measuring & Cutting
- Basic Drywall Hanging: How to Hang Drywall
- Drywall Taping, Joint Compounds & Sanding
- Advanced Drywall Techniques
- Decorative & Special Drywall Finishes
- How to Repair Drywall: Patching & Repairing Walls and Ceilings