How To Plaster a Wall

Plastering a wall can transform the look and feel of a room. This traditional method creates a smooth, durable surface that’s perfect for painting or wallpapering. While it requires practice to master, understanding the basics can help homeowners tackle projects big and small. In the video above, This Old House master plasterer Stephen Norton demonstrates the proper technique for plastering a wall.

Benefits of Plaster Walls

Plaster walls offer several advantages over other wall finishes:

• Durability: Plaster is harder and more resistant to dents and dings than drywall.
• Sound insulation: The density of plaster helps reduce noise transmission between rooms.
• Fire resistance: Plaster is naturally fire-resistant, adding an extra layer of safety to your home.
• Customization: Plaster can be molded and shaped to create unique architectural details.

Types of Plaster

There are several types of plaster available for different applications, such as:

• Veneer plaster: A thin coat applied over specially prepared drywall or masonry.
• Traditional three-coat plaster: Consists of a scratch coat, brown coat, and finish coat.
• Ornamental plaster: Used for creating decorative moldings and details.

Preparing for Plastering of Walls

You’ll need the right conditions to get started on your plastering job, as well as the necessary tools and materials on hand to make things go smoothly.

Ideal Conditions for Plastering

Certain conditions are optimal for plastering. Aim for a room temperature of around 55–60 degrees Fahrenheit and low humidity. High humidity can make the plaster drag and slow down the setting process. Good air circulation also helps the plaster dry evenly. 

Preparing the Wall

Before you cover the entire wall in plaster, you’ll first tape the seams of the wallboard and use plaster to cover any joints and corner beads. This creates a smooth work surface and prevents cracking.

Essential Tools and Materials

To plaster a wall, you’ll need:

• Veneer plaster
• Flat trowel
• Drywall hawk
• Mixing bucket
• Water
• Stilts or stepladder (for reaching high areas)
• Corner beads (for sharp edges)
• Drop cloths (for protecting the floor)

The Plastering Process

Plastering a wall requires a specific technique to achieve a smooth, even finish. Here’s a step-by-step guide for applying veneer plaster, which Norton also refers to as “mud,” as shown in the video above: 

1. Mix the plaster: Follow the manufacturer’s instructions for the correct consistency.
2. Wet the hawk: Wetting the hawk prevents the plaster from sticking.
3. Load the hawk: First, take a small amount of plaster and spread it around on the hawk. Then place a mound of plaster onto the hawk. If your mound extends to the edge, clean off the edge of the hawk so that the plaster is in the center.
4. Transfer to trowel: Scoop some plaster onto the center of the trowel. The scooping motion should be from the bottom up.
5. Apply to the wall: Start in the middle of the wall, applying the plaster with an upward sweeping motion, then come back down, bending your knees as you reach the bottom to get a smooth, sweeping motion. Work from left to right as you spread it out.
6. Spread evenly: Use even pressure to spread the plaster thinly and smoothly.
7. Overlap strokes: Work your way across the wall, overlapping each stroke slightly.
8. Complete the top area: To plaster the top of the wall beyond your reach, you’ll need to use a ladder or stilts. Take the trowel and make a hard angle going across for a clean line that meshes with the lower part of the wall. Having the top area clean makes it easier to apply paint or molding later.

Tips for Applying Plaster

When applying the plaster, keep these tips in mind:

• Maintain consistent pressure on the trowel for an even application.
• Try to keep the “mud” in the center of your trowel as you’re applying it. This will cause it to flatten out as you go.
• Work quickly, as you typically have about 30 minutes before the plaster begins to set.
• Start from the bottom and work your way up, using smooth, sweeping motions.

Smoothing and Finishing

After applying the plaster: 

1. Set slightly: Allow the plaster to set slightly before smoothing.
2. Smooth out imperfections: Use the trowel to smooth out any blemishes.
3. Achieve a paint-ready finish: Work the surface until you achieve a smooth, paint-ready finish.

Cleaning Up

After plastering, clean your tools to remove any remaining plaster and properly dispose of any waste materials. Also, be sure to inspect your work for any imperfections that may need further smoothing.

Common Challenges and Solutions When Plastering a Wall

Even experienced plasterers face challenges. Here are some common issues and how to address them:

Avoiding “Holidays”

“Holidays” are blemishes or imperfections in the plaster surface. To avoid them:

• Maintain consistent pressure when applying the plaster.
• Ensure complete coverage of the wall.
• Work in good lighting to spot any missed areas.

Dealing with Fast-Setting Plaster

If the plaster is setting too quickly:

• Work in smaller sections.
• Have a helper mix fresh batches as needed.
• Consider using a retarder additive to slow the setting time.

Achieving Crisp Corners

For clean, sharp corners:

• Use corner beads for protection and as a guide.
• Apply extra care when plastering near corners and edges.
• Use a corner trowel for a precise finish.

Handling Large Areas

When dealing with large wall surfaces, break the wall into manageable sections and ensure that each section blends seamlessly into the next. Consider working with a partner to ensure a smooth, continuous application that will be done more quickly. 

Safety Precautions While Plastering

Safety is paramount when plastering. Here are some precautions to consider:

• Protective gear: Wear safety goggles and gloves to protect your eyes and hands.
• Proper ventilation: Ensure that the area is well-ventilated to avoid inhaling plaster dust.
• Ladders and stilts: Use ladders and stilts carefully to prevent falls.

Professional vs. DIY Plastering

While it’s possible to plaster a wall yourself, you may also want to consider hiring a professional for certain projects. DIY plastering can help save on labor costs and give you a flexible timeline and sense of personal achievement, but there’s a steep learning curve for inexperienced DIYers, and it can be a time-consuming process. Norton mentions that it takes about two years before members of his crew are proficient at the task.

Hiring a professional has a higher upfront cost and can lead to potential disruption in your home, but it guarantees high-quality results, faster completion, and few to no mistakes.