Understanding the Importance of Keys in Lath Walls

When it comes to repairing plaster and lath walls, understanding the role of keys is crucial for achieving a smooth finish. In fact, without these curls of plaster, the wall would be prone to cracking and damage over time. But what exactly are keys, and how do they help keep the plaster on the lath? In this article, we'll explore the process of repairing plaster and lath walls, including the importance of keys and the steps involved in achieving a professional-looking finish.

Applying Plaster Coats

The process of applying plaster coats is a crucial step in repairing plaster and lath walls. Typically, three coats of plaster are applied to achieve a smooth, white finish. The first coat, known as the 'brown coat,' provides a rough, sandy base that helps to create a uniform undercoat. The second coat, or 'browning' layer, is then applied, leaving about 1/2 inch of rough plaster between coats.

Once the wall is fully covered, the vertical lath guides are removed, and their slots are filled in with new plaster. This process creates a smooth, even surface that's ready for painting.

The Role of Laths

Laths play a crucial role in repairing plaster and lath walls. These narrow strips of wood, metal, or split boards are nailed horizontally across the wall studs or ceiling joists to create a framework for the plaster. The laths provide a surface for the plaster to adhere to, ensuring that it stays in place over time.

Types of Laths

There are several types of laths available, including sawn, riven, and split hardwood laths. In Canada and the United States, laths were generally sawn, while in the UK and its colonies, riven or split hardwood laths of random lengths and sizes were often used.

Tips for Repairing Plaster and Lath Walls

When it comes to repairing plaster and lath walls, there are several tips to keep in mind. First, make sure to apply a smooth, even layer of plaster to ensure a professional-looking finish. Second, use the right type of plaster for your project, taking into account factors such as climate and humidity.

Finally, don't forget to remove any vertical lath guides once the wall is fully covered, and fill in their slots with new plaster to create a smooth surface.

By following these tips and understanding the importance of keys, you'll be well on your way to achieving a beautiful, long-lasting finish for your plaster and lath walls. Whether you're a DIY enthusiast or a professional contractor, repairing plaster and lath walls is a valuable skill that can add value and character to any home or building.

Repairing plaster and lath walls