The Do’s and Don’ts of Plastering an Outside Wall

When it comes to enhancing the appearance and resilience of a home’s exterior, few finishes are as effective as plaster. At West & Sons Construction, plastering an outside wall is a craft we've perfected over generations—spanning more than 100 years in the construction industry. As Licensed Building Practitioners serving the Auckland region, we’re here to share our professional insights into this construction process. This blog is not a DIY guide as such; instead, it's meant to help homeowners understand the care, expertise, and precision involved in plastering an outside wall, so you know your project is in the best hands.

Why Choose Plaster for Your Outside Walls?

Plastering an outside wall offers numerous benefits, especially in a city like Auckland, where homes face a variety of weather conditions. A high-quality plaster finish enhances a property's aesthetic appeal, adds a layer of protection against the elements, and improves insulation. Whether you’re renovating an older home or completing a new build, expertly applied plaster transforms ordinary walls into durable surfaces, that also look great.

That said, success in plastering an outside wall depends heavily on proper preparation, application, and finishing. Cutting corners or making mistakes can lead to a host of issues, including cracking, peeling, and water infiltration. At West & Sons Construction, we’ve seen it all—and we know exactly what works and what doesn’t. This is why we recommend plastering an outside wall is best left to the professionals.

Plastering an Outside Wall

Starting with the essentials. Here’s what your plasterers absolutely must do when plastering an outside wall:

1. Select the Appropriate Plaster Material

Selecting the appropriate plaster is imperative for achieving durability and a flawless finish. In Auckland’s climate, we recommend using a cement-based plaster that can withstand moisture and temperature fluctuations. A professional-grade plaster will also ensure better adherence and longevity. We used tried and tested brands that often come with a product guarantee.

2 Clean and Prepare the Surface

Plaster can’t work its magic on a dirty or uneven surface.One of the first steps we take at West & Sons Construction is thoroughly cleaning the wall, removing dust, grease, and loose materials. If there are any cracks or gaps in the substrate, we repair these to create a solid and smooth foundation for the plaster.

3. Utilise Quality Tools and Techniques

Plastering an outside wall requires precision, and the right tools play a huge role. From trowels to floats, each piece of equipment must be of top-notch professional quality to ensure a smooth and consistent application. Our team uses tried-and-true techniques refined over decades to achieve a flawless finish every time.

4. Apply Multiple Layers

One layer of plaster isn’t enough to achieve the desired finish. Depending on the condition of the wall and the project requirements, we often apply a three-coat mesh plaster system comprising of a base coat, mesh then followed by a finishing coat. Each layer is allowed to cure properly to prevent cracking.

5. Plan for Proper Drainage

As we know, heavy rain is a common occurrence in New Zealand. Plastering an outside wall involves ensuring proper drainage by shaping subtle slopes or falls to prevent water from pooling on the surface. This not only extends the life of the plaster but also enhances safety.

Pitfalls of Plastering an Outside Wall

Now, let’s look at some obstacles to be avoided by your professional plastering team. These are some common mistakes that can compromise the integrity and appearance of your plastered wall:

1. Poor Weather Considerations

Plastering in the wrong conditions can lead to disaster. Excessive heat can cause the plaster to dry too quickly, while rain can wash it away before it sets. At West & Sons Construction, we always check the weather forecast and plan accordingly to ensure the best results for your project.

2. Applying Plaster to an Unstable Surface

Plaster needs a strong, stable base to adhere properly. Plastering over a loose or damaged wall will almost certainly lead to cracks and peeling down the line. This is why surface preparation is such a critical step in the process.

3. Rushing the Curing Process

Patience is key when plastering an outside wall. Rushing the curing process can result in weak plaster prone to cracking. We always allow sufficient time for each coat to set and dry before moving on to the next step.

4. Neglecting Waterproofing

Auckland’s damp climate makes waterproofing essential for exterior plaster. While quality plaster has inherent moisture resistance, we often enhance this with additional sealants or coatings to protect your walls from water damage.

5. Skipping the Final Paint Coat

Plaster alone doesn’t provide the finished look or complete protection. The final step in any plastering project is applying a high-quality paint or protective coating. At West & Sons Construction, we use paints specifically designed for exterior use, ensuring a stunning and durable finish that stands up to Auckland’s weather.

Plastering an outside wall is both an art and a science, requiring expertise that comes from years of experience. At West & Sons Construction, we bring over a century of knowledge to every project we undertake. As Licensed Building Practitioners, we follow strict industry standards and use only the best materials and techniques.

Our team is deeply familiar with Auckland’s unique climate and construction challenges, and we tailor our approach to deliver results that exceed expectations. When you work with West & Sons, you’re not just hiring builders—you’re partnering with craftsmen who take pride in their work and are committed to helping you create a home you’ll love for generations.

Plastering an outside wall is a transformative process that requires careful planning, skilled execution, and attention to detail. From selecting the right materials to ensuring proper curing and waterproofing, every step matters. And, of course, the final coat of paint is the finishing touch that ties it all together, providing a great final look and long-lasting protection.

At West & Sons Construction we approach every project with the same care and dedication we’d give our own homes. If you’re considering plastering an outside wall, don’t leave it to chance.