How to Repair Plaster Walls

Plaster walls add character to many homes, especially older ones. However, over time, they can suffer damage. Knowing how to repair plaster walls is a valuable skill for homeowners. This guide will walk you through assessing, preparing, and repairing these walls.

Assessing the Damage

Begin by examining the wall closely. Look for cracks, holes, or bulging. Each type of damage requires a different approach.

Cracks are common and usually surface-level. They often occur due to temperature changes or settling. Small cracks can be easily patched, but wide cracks might indicate structural issues.

Holes might form from accidental impacts or where fixtures once were. Small holes are simple to repair. Large ones require more effort and materials.

Bulging plaster may indicate water damage or detachment from the lath. This situation needs careful inspection to determine the underlying cause. It may require professional intervention if structural issues are present.

Gathering Materials and Tools

Once you know the extent of the damage, gather the necessary tools and materials:

• Plaster patching compound or joint compound
• Putty knife or plaster trowel
• Sandpaper or sanding sponge
• Primer and paint
• Clean cloth or sponge
• Protective eyewear and mask (for dust protection)
• Utility knife
• Lath and securing material (if required for larger repairs)

Having everything ready before you start will make the process smoother.

Preparing the Area

Before you begin repairs, prepare the area. Start by cleaning the surface. Use a damp cloth to wipe away dust and debris. This ensures good adhesion for your patching material.

For cracks, widen slightly with a utility knife. This might seem counterintuitive, but it allows the patching material to fill the crack completely and adhere better.

If dealing with larger holes, ensure any loose material is removed. For bulges, gently tap the area. Listen for a hollow sound. If the plaster has detached from the lath, it might need re-securing before applying any patching material.

Patching Cracks

After preparation, patching cracks is straightforward. Use a putty knife to apply plaster patching compound. Work the compound into the crack, ensuring it’s slightly overfilled. This prevents shrinkage when it dries.

Feather the edges with your knife to blend into the surrounding wall. Allow it to dry according to the manufacturer’s instructions. Once dry, sand it lightly to smooth the surface.

Fixing Holes

Repairing small holes involves similar steps as cracks. After clearing out any debris, fill the hole with patching compound. Use your putty knife to level it with the wall surface. Again, allow it to dry before sanding.

Larger holes require more steps. You might need a backing material like wire mesh or lath. Secure the mesh or lath inside the hole. Apply layers of patching compound, letting each layer dry before applying the next. Build up until it matches the wall’s surface. Sand as needed for a smooth finish.

Addressing Bulges

Fixing bulges often starts with diagnosing the cause. If caused by moisture, address the source first. This might involve fixing a leak or improving ventilation.

Once dry, you’ll need to reattach the plaster to the lath. This can involve using plaster washers. Drill small holes around the bulge’s perimeter. Secure washers into the lath. Apply patching compound over the repaired area. Sand once dry to match the surrounding surface.

Priming and Painting

With the repairs complete, move on to priming. Primer helps seal the patch and provides a good base for paint. Apply a coat of primer with a roller or brush. Let it dry fully before painting.

Choose a paint that matches the existing wall color. Apply at least two coats for even coverage. Use a roller for larger areas and a brush for edges.

Maintenance Tips for Plaster Walls

Regular maintenance can prevent future issues. Keep an eye on moisture levels in rooms with plaster walls. Too much moisture can cause bulging or cracking.

Address any small damage immediately. This can prevent larger issues from developing. Regularly inspect high-traffic areas or places prone to impacts.

If you notice recurring problems, consider consulting a structural expert. Persistent issues may indicate underlying structural problems.