How to Hang Double Wallboard

Use the right size drywall screw to ensure a quality installation.

Although most projects require only a single layer of wallboard, sometimes it can help to add another layer. For example, if you are soundproofing a room, a double layer of wallboard will help cut down on sound transmission through the wall. Similarly, projects requiring extra heat insulation will benefit from an extra-thick wall or ceiling. Whatever your reason, the key to hanging a double layer of wallboard is finding the right drywall screws. You need screws that will penetrate deep enough to adequately support the wallboard. Drywall screws are available in many sizes at most retail hardware stores.

Things You'll Need

• Drywall screws
• Utility knife
• Screw gun
• Joint compound
• 6- and 12-inch drywall knives
• 100-grit sandpaper

Instructions

1. Add together the thicknesses of both layers of wallboard, then add 5/8 inch to the total to calculate how long your drywall screws should be. For example, if you are hanging two layers of 1/2-inch wallboard, you need drywall screws at least 1 5/8 inch long. These screws will be long enough to penetrate through both layers of wallboard, then penetrate the wood studs deep enough to hold both boards up.

2. Hang the first layer of wallboard. Measure and cut to size each panel of wallboard. Use a utility knife to make each cut. Then hold the panel against the wood studs where you want to install it. Attach the panel by installing drywall screws every 5 to 7 inches. Use a drywall screw gun for maximum efficiency. Note that for this step you can use regular drywall screws (which are 1 1/4 inch long) if you wish, but there is no harm in using the long screws.

3. Hang the second layer of wallboard. Measure and cut to size each panel you wish to hang, just as you did for the first layer. Place the panel over the first layer and install the long screws through both layers of wallboard and into the wood studs. If you have trouble finding the stud, note the location of all the screws you installed for the first layer.

4. Finish the wallboard as normal. Press joint compound into the joints where the panels of wallboard meet. Place paper drywall tape over each joint, then press the tape into the joints by wiping them with a 6-inch drywall knife. Allow the work to dry overnight, then cover all the tapes with joint compound, using a 12-inch drywall knife. After the joint compound dries, sand everything with 100-grit sandpaper.

References

• Education Resources Information Center: Drywall Finishing Guide (PDF)
• Habitat for Humanity: Drywall Installation Guide (PDF)