Yes, you can install drywall over plaster, but there are important factors to consider. While it can create a smooth, flat surface, it is often not the best approach. Installing drywall over plaster will increase the wall's thickness, which can cause issues with existing window and door frames that may no longer fit. You might also need to adjust power outlets to keep them accessible. A better, though more expensive, option is to remove the old plaster and lath entirely before installing new drywall. Drywalling directly over plaster seals in the old material, and if any problems arise later, you will need to remove both layers down to the structural beams for repairs. Given the potential complications, this job is best handled by professionals.

You should start looking for a drywall installer by choosing a local company with positive online reviews and ratings with the Better Business Bureau (BBB). Next, confirm that the professional is properly licensed using Angi’s contractor licensing tool, and ask the installer if they are fully insured. It’s a good idea to ask for recent customer references and call them to get their honest opinion about the contractor and their work. You can also ask the installer if they guarantee their work or provide a workmanship warranty.

Drywall can be installed directly on ceiling joists. In fact, this method is common in many construction projects. Drywall sheets are attached to the joists using screws, ensuring a secure and stable installation. Before attaching the drywall, it's important to mark the joist locations on the ceiling, allowing for accurate screw placement. Proper spacing between screws and careful taping and mudding of joints are crucial to creating a smooth and flawless ceiling surface. If the joists are in good condition and level, installing drywall directly on them is a practical and efficient approach.

Plaster that sags or bulges, shows extensive deep cracks, or is crumbling from water damage or simply time may need replacement. Plaster walls can look a little “worn” for a long time before they need replacing. The only real way to know if it needs a replacement is to hire a professional to assess the condition of the plaster.