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.

Yes, as drywall mud is going to have some uneven spots and bumps after application. Such imperfections are going to be visible after everything dries and even after you paint the wall, so you want to remove them. Learning how to sand drywall, taking your time, and following drywall sanding tips can help you have the best results.

If you plan on heating your garage, you must install a vapor barrier when drywalling the garage. A vapor barrier protects your garage from frost and mold that can occur through condensation. If your garage is unheated, you don't need to install a vapor barrier. The only exception is if you regularly crank the heat in your car before getting in it. In this case, you may still want to install a vapor barrier, as your car can heat your garage.

Venetian plaster is a highly durable wall finish that becomes a rock-like substance once dried, making it last longer than most other wall finishes. Its lifespan can range from decades to centuries, potentially lasting a lifetime. Key factors influencing its longevity include the quality of the initial application, whether it's properly sealed against moisture, and how the wall is maintained and treated (e.g., how often it is touched or bumped). Due to its mineral content, it can also develop a patina over time.