Fixing Plaster and Lath Walls: Restore Strength and Appearance

Plaster and lath walls, once a staple of historic and traditional construction, often develop cracks, holes, and deterioration over time—compromising both structure and aesthetics. Successfully repairing these surfaces restores integrity and enhances your space’s character.

Begin by inspecting the wall to identify cracks, loose plaster, or missing laths. Clean the area thoroughly to remove dust, loose debris, and old adhesive. Sand rough edges gently, then use a chisel to remove unstable plaster around damage. Prepare surfaces by dampening cracks to improve adhesion of repair materials. For lath walls, check for rot or insect damage—replace any compromised laths with matching wood to ensure structural stability.

For small cracks and surface damage, apply a flexible plaster patching compound, spreading it evenly and smoothing with a trowel. For larger holes, mix a plaster of Paris blend with fine sand, applying in thin layers to avoid sagging. When working with lath, reattach loose laths using lime-based mortar, securing them firmly before re-plastering. Always use traditional materials where possible—this ensures breathability and longevity. Consider applying a thin coat of skim plaster over repairs for a seamless, professional finish.

Once repairs are dry, lightly sand the surface to match the surrounding area, then prime and paint using a breathable finish to prevent moisture buildup. Regularly inspect walls for early signs of wear, especially in high-moisture areas. Prompt attention to minor issues prevents costly damage and extends the life of your plaster and lath walls.

Severe structural damage, extensive mold growth, or widespread lath decay often require expert intervention. Licensed contractors bring specialized tools and experience to restore integrity safely and effectively, minimizing disruption and ensuring code compliance.

Fixing plaster and lath walls isn’t just about aesthetics—it’s essential for preserving structural soundness and historical value. With the right techniques and materials, even challenging repairs yield durable, beautiful results. For complex projects, trust qualified professionals to deliver lasting quality and peace of mind.

Follow this step by step guide to help with your lath and plaster repair. We share how to fix a damaged wall. Or, if the lath behind the old plaster is in good condition then how to patch a hole plaster walls by troweling on layers of mud.

Fixing to lath and plaster walls has always been a tricky problem and one that has always puzzled first time DIY'ers, however there are several solutions to this conundrum which we run through below. What is Lath and Plaster? Lath and plaster is a type of traditional wall finish, similar to plaster, that was first used around the 1700's all the way up to the mid 18th century. It uses thin.

Lath and plaster construction was the standard for interior walls in homes built before the mid-20th century, and it differs substantially from modern drywall. This system involves narrow strips of wood, known as lath, being nailed horizontally to wall studs, over which multiple layers of wet plaster are applied [cites: 1, 3, 6]. How to Repair Plaster Walls Fix the Lath If the underlying layer of metal or wood, known as the lath, is damaged, then it will need to be patched before you can continue.

Use a prybar and keyhole saw to cut out any damaged pieces of lath. Cut new wood or metal lath, then slide it into the hole and secure it to the stud using drywall screws. Learn how to fix old plaster and lath walls with this detailed guide.

Restore your home's charm with practical tips and tools. Discover the best methods for repairing lath and plaster walls. Our expert guide provides step.

How to Repair Cracks in Old Plaster and Lath Walls & Ceilings - Spencer Colgan Dangerous Idiots Fastest Truck & Heavy Equipment Fails Extreme Oversized Truck Transport #7. Plaster washers, which are perforated metal discs, are screwed through the loose plaster into the lath to temporarily hold the section flat against the wall while the injected adhesive cures. For small to medium holes where the lath is present, the repair recreates the original three.

Here's how to repair cracks in your historic plaster walls and maintain a smooth surface that will last. Lath and plaster was a method of finishing off walls and ceilings used from early in the 18th century right up until the mid-20th century - when modern methods for plastering walls began to be used and sheet plasterboard became more commonplace. If your property has lath and plaster, or are considering buying one, this guide looks at how they were constructed and how they can be repaired if.