How to Mud a Plaster Wall
If you have plaster walls that are badly cracked or have large holes, there are two main ways to repair this damage. You can use plaster, a medium that is difficult to work with for beginners, or you can use joint compound, or drywall mud as it is sometimes called. Joint compound is much easier to work with, does not set as quickly and is a more forgiving medium when it comes to fixing mistakes. Keep in mind that joint compound is darker in color than plaster, so you will need to prime and paint the area to blend it in with the remaining plaster on the walls.
Protecting the flooring underneath the wall by laying down plastic dropcloths. You can tape these into place to keep them from shifting while you work.
Use a chisel to knock away any debris around the crack or hole. The edges need to be free of any hanging debris, no matter how small, to avoid having the debris get into the mud.
Apply joint compound over the hole with a drywall or putty knife. Use a sweeping motion and work upward. Use enough to fill in any holes or cracks, but do not over-apply. Scrape off the excess compound as you work. Let the compound set until it is hard.
Sand down the compound with a fine-grit sanding block. The surface should be smooth to the touch and flush with the rest of the wall. Run your hand over the compound as you work to help you find any uneven areas that may be hard to see.
Things You Will Need
- Joint compound (mud)
- Drywall knife
- Sanding block, fine-grit