While plaster walls have received a bad rep from some, they are desirable to many property owners due to their strength, sound dampening properties and resistance to fire. Before 1950 plaster walls were extremely popular and was used as a covering which was placed over masonry or lathe. However, you will eventually have to repair plaster walls as they are vulnerable to cracking, holes and dents over time. Below are some methods for repairing plaster rather than replacing it outright. Tools you will need for this project include patching plaster or plaster which is ready mix, sandpaper, towels, and a trowel and fiberglass tape.
Repairing Holes
You will first need to break down the plaster which is loose and then use a towel to clean the spot. You will next want to put together a mixture of plaster base which is ready made along with water, combining the two in a bucket while following the instructions of the manufacturer. Next you will want to fill up the hole while using a plaster base coat with a trowel that is medium in width. The plaster compound should be scraped until it is ¼ inch beneath the plaster’s finished surface. Let it set but don’t let it dry.
Add a second plaster coat using the trowel. If the hole is bigger than four inches, the plaster should be scraped out until it’s beneath the current surface of the wall. You can also use the trowel’s straight end to smoothen the plaster until it is smooth and aligned with the remainder of the wall. A third plaster coat can be applied as needed after the previous coat has set but isn’t yet dried.
Repairing Cracks
To repair cracks, you will want to start by chipping away plaster which is loose. You will next want to sand the surface lightly using sandpaper which is medium grit. Clean the area thoroughly with a fresh towel. After this is done you will next need to use patching plaster to fill the crack in. If the crack is larger than ¼ inch, use fiberglass tape on the plaster and crack, allowing the area to dry. You will then need to add a second coat of the patching plaster. Feather it on the wall, allowing the plaster to dry and then adding a third coat as needed. The surface will then need to be sanded using sandpaper which is fine grit after the plaster has totally dried.
Additional Tips
Patching plaster is available in pre mixed form at most home improvement stores. You should always check for paint lead when performing renovation on older properties, and if the cracks are the result of structural problems inside the building, these underlying issues must be repaired otherwise the cracks will come back. Overall, performing repairs on plaster on masonry requires less work than plaster on lathe and will result in a surface which is clean and smooth. At GreenTree Construction NYC we have many years of experience in all forms of renovation so these types of projects are best left to us!