Get matched with top plaster repair specialists in Kanab, UT

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.

If your home was built before the 1940s and was not remodeled in the past 50 or so years, you probably have plaster walls. Aside from assuming, there are some practical ways to tell if you have plaster walls, including the following: If you knock on the wall and it feels solid, not hollow, if you can’t insert a thumbtack easily, if there are cracks that look like spiderwebs, or if your home has curved, arched, or swirled walls, doorways, or window openings.

If you have an unfinished basement or attic, you could examine the backs of any finished walls to check, too.

You can put certain types of plaster over other types, but doing so isn't always the best idea. For example, putting a coat of gypsum over lime plaster is possible, but doing so will limit the lime plaster's breathability and potentially affect its performance.

Since cement plaster tends to leave a textured surface, no matter how much you smooth it, some people prefer to use gypsum plaster as a topcoat over cement plaster, creating a smoother surface.

This depends on how much plaster is applied and in how many layers, but a decent estimate is around 150 square feet. If you are applying only two coats on a small wall, there is a chance you may only need one or two gallons for the entire project. If you are plastering a large living room wall with high ceilings, using one of the more involved techniques–like Scagliola–that requires several coats, expect the project materials costs to add up quickly.