Hanging drywall over existing drywall is known as a "drywall overlay" or "double-layer drywall" installation. It is typically done when there is a need to improve the appearance, cover damaged or textured walls, or enhance soundproofing. Here's a general guide on how to hang drywall over existing drywall:
Assess the condition of the existing drywall: Inspect the existing drywall for any signs of damage, such as water stains, cracks, or bulges. Repair any significant damage before proceeding with the overlay. Ensure that the existing drywall is structurally sound and firmly attached to the wall.
Prepare the work area: Clear the room of any furniture, fixtures, or obstacles. Cover the floors and any remaining furniture with drop cloths or plastic sheets to protect them from dust and debris.
Measure and cut the new drywall: Measure the dimensions of the walls where the new drywall will be installed. Transfer these measurements to the new drywall sheets and use a utility knife or drywall saw to cut them to size. It's recommended to stagger the joints between the existing and new drywall for added stability.
Apply construction adhesive: Apply a continuous bead of construction adhesive to the back of the new drywall sheets, concentrating on the edges and field (center) of each sheet. This adhesive helps improve the bond between the layers of drywall.
Install the new drywall: Lift the new drywall sheet into place against the existing drywall, aligning it with the edges and corners. Use drywall screws or nails to secure the new drywall to the existing drywall, ensuring they penetrate into the underlying wall studs or existing drywall anchors. Space the screws or nails approximately 12 inches apart along the edges and 16 inches apart in the field.
Tape and mud the seams: Once the new drywall is installed, apply drywall joint tape over the seams between the new and existing drywall. Use a taping knife to apply a thin layer of joint compound (mud) over the tape, feathering the edges to create a smooth transition. Allow the compound to dry according to the manufacturer's instructions, then apply additional coats of mud as needed, sanding between each coat for a smooth finish.
Finish the drywall: After the joint compound is dry and sanded, apply a coat of primer to the entire wall surface. This helps ensure a uniform paint finish. Finish the walls with your desired paint or other wall coverings.
It's important to note that adding a second layer of drywall can increase the weight on the existing walls. Make sure your wall structure can handle the additional load, and consult a professional if you have any concerns about the structural integrity or building codes. Additionally, check local building codes and regulations before proceeding with a drywall overlay, as some jurisdictions may have specific requirements or restrictions.