Lath and Plaster Wall Repairs: A Step-by-Step Guide

When it comes to repairing lath and plaster walls, it's essential to follow the correct techniques to ensure a seamless finish. Whether you're dealing with small or large holes, this guide will walk you through the process of repairing your lath and plaster wall.

The first step is to prepare the area around the hole by dampening the surface. This helps the new plaster adhere properly. Next, apply a finishing floating layer of plaster to bring the level up to the surrounding plaster. Repeat this process for each subsequent coat, ensuring that you keep the level below the surrounding plaster to allow room for the floating and setting layers.

For larger holes, it's recommended to use proper plastering techniques rather than relying on filler alone. Begin by cleaning the laths and surrounding plaster to remove any loose plaster or dust. Ensure that the gaps between the laths are clear, then apply a coat of render making sure it's forced between the laths.

Between each coat, lightly sand the surrounding plaster surface (but be gentle as lime plaster is extremely soft) and moisten the previous filler before applying the next coat of plaster filler. The filler used in holes may shrink as it hardens, so you may need to apply multiple coats to achieve the desired level.

To level off the filler, use a wet filling knife across the hole. If the hole is too wide to be bridged by the knife, work on the edges first and then move to the middle section. Press the plaster filler into the hole, making sure it's pushed into the edges so that it's proud of the surrounding plaster.

For smaller holes, simply clean all loose plaster and dust from the area, cutting back the render if necessary to give a deeper depression in the plaster. If possible, undercut the plaster at the edges of the hole to provide a good key for the filler.

It's essential to use the same type of materials or similar when doing a repair to lath and plaster. This ensures a consistent finish and minimizes the risk of further damage. By following these steps, you can achieve a professional-looking repair that blends seamlessly with the surrounding area.

For more information on basic lath and plaster construction and techniques, be sure to check out our detailed guide. With practice and patience, you'll be able to tackle even the most challenging repairs with confidence.

Lath and plaster wall