How to Repair Cracks and Chips in Plaster Walls


Cracks and chips in your plaster walls are not always easy to fix, but they can be fixed in several ways. Learn how to apply joint compound, smooth seams and use fiberglass mats to patch plaster. You may need to call a professional contractor for bigger issues, but a handy homeowner can repair most plaster problems.

Cracks in plaster

Cracks in plaster walls can appear in different shapes and sizes. There are two main types. A non-structural crack is fine and shallow, while a structural crack is wide and extends through the entire depth of the plaster. The former occurs when the sand is unevenly distributed or the plaster is allowed to dry too quickly.

If the crack is not large, you can try using a putty knife to undercut the crack and apply a thin layer of filler. This will help to make the patching material adhere to the wall and give it a smoother appearance. However, you should note that too much putty is not recommended. You can also try plastering first, which is often better if the crack is small.

Another type of repair for cracks in plaster walls is to use a joint compound. This joint compound can help fill in the holes and repair the plaster.

Applying joint compound

Applying a joint compound to repair plaster walls can be a challenging task. You should take a few key steps to ensure a smooth, even finish. First, sand the area with a fine-grit sandpaper. Next, apply another coat of joint compound. This will blend the texture.

When patching plaster walls, make sure the wall is clean and free from debris. You should also ensure the cracks are wider than 1/4 inch in width. It would help if you also taped the joints. After applying the patching compound, it will interlock with the old plaster. When it has hardened, you can paint or wallpaper the area.

When applying joint compound to repair plaster walls, you must use the right type. If you’re unsure which type to use, you can visit a home improvement store to learn more. A joint compound is a type of drywall mud used on many surfaces, including plaster. This material has a high adhesiveness and can be applied in multiple layers for the best results.

Smoothing out seams

Before repairing plaster walls, it is important to smooth out the seams. This step will prevent stress cracks. Next, it is recommended to begin repairing the plaster at the outer edge and work your way toward the center. It is also a good idea to clean the area thoroughly with a sponge and water before continuing.

To smooth the seams, use a joint compound. This is a dry powder that sets in about 20 to 90 minutes. Once dry, use a 12-inch knife to apply a third compound layer. The third layer will help blend the repair with the wall’s surface.

Next, you must repair the wood lath underneath the plaster. Most people will attach this piece of wood with screws and metal washers, but Silva has recently tried Big Wally’s Plaster Magic. This glue eliminates the need for screws and is easier to work with. It also looks better than screws and washers.

Using fiberglass mats

A wide sheet of fiberglass mat can be used to stabilize cracked or crumbling plaster walls. These can be purchased at home centers and can be applied to walls or ceilings. When applied properly, the fiberglass mat will prevent future cracks from forming. It will also protect against structural damage.

Using fiberglass mats is relatively simple. It is a cost-effective method for repairing plaster walls. First, you need to clean and smooth out the surface. Then, use a brush to apply the glass fiber to the surface. Ensure that the glass fiber is dry before applying it, as moisture may cause the material to darken.

The fiberglass mat cuts easily, and no sharp knife is required. Once the mat is positioned correctly, use a taping knife to cut a test hole about half an inch away from the hole to be repaired. Once the fiberglass mat is properly positioned, you can apply a second coat of joint compound and tap off any excess material. The finished product will take at least 24 hours to dry. After that, you can sand it smooth with fine sandpaper.