How to Replace Crumbling Plaster Above a Fireplace Mantel
- 1). Scrape the crumbling plaster wall with a scraper to remove any loose pieces. Dust the hole and spray with water until absorbed into the wall.
- 2). Apply a bonding agent and let it dry for 45 minutes.
- 3). Fill the hole with plaster, using a 100mm broad knife. Fill in from the center and spread out. Smooth out with the broad knife and draw in a cross-hatch pattern into the wet plaster with a filler knife. Then let it dry.
- 4). Apply a finishing coat of plaster, using a 150mm broad knife. Smooth out until even with the wall. Apply another skim coat if needed. Let it dry.
- 5). Sand the wall with medium-coarse sandpaper. Dust off any excess debris.
- 6). Prime and paint as needed.
