Plaster and Stucco may appear similar to the untrained eye, as they both contain cement and are applied to walls in similar ways. However, it is important to note that stucco is a specialized type of plaster and the two cannot be used interchangeably. They differ in their material compositions, use cases, and installation processes.
Before making a decision, it is essential to grasp the distinctions between these materials to avoid choosing plaster when stucco is desired, or vice versa.
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Main Difference Between Stucco And Plaster
While both stucco and plaster are long-lasting, some of them possess fire-resistant properties as they are composed of different materials. As a result, people frequently tend to mix them up. Stucco is made from Portland cement, whereas plaster is made from gypsum.
When it comes to stucco and plaster, they may seem similar in appearance and durability, but they each have their own unique qualities, as we mentioned before. Understanding these differences is crucial to determining which material best suits your specific needs.
Additionally, the application and repair processes for both materials require considerable labor. However, stucco can only be applied externally, while plaster can be used both indoors and outdoors, making it a more versatile option.
Stucco And Plaster Material Composition
The composition of plaster vs stucco sets them apart from each other. Both contain cement and sand, but plaster has a base of gypsum while stucco has a base of lime.
Due to its softer nature, plaster is more delicate than stucco. This affects where each material is used and how they are installed, which we will discuss later.
In terms of protection against damage, both materials, thanks to their cement content, offer similar levels of security for your home. However, the softer surface of plaster leaves it more vulnerable to blunt force damage.
The variation in ingredients between stucco and plaster extends beyond just the base material. Modern stucco sometimes incorporates fiberglass strands to enhance its strength and structural support.
Furthermore, stucco is prone to cracking for various reasons, as its harder consistency makes it less tolerant to stresses like settling of the home. However, the inclusion of fiberglass strands in stucco helps prevent or minimize these cracks.
Stucco vs Plaster Applications: Indoor versus Outdoor
Plaster is multifaceted and can be used both indoors and outdoors, although it is more commonly used indoors because of its softer surface. Stucco, on the other hand, is exclusively designed for outdoor applications due to its rougher texture and specific installation process.
Indoor use of plaster offers a timeless aesthetic that modern drywall cannot replicate. It can even be applied to ceilings, creating a cohesive look throughout your home.
For outdoor plaster applications, there are specially formulated plasters that can withstand the elements. However, the most specialized outdoor plaster is stucco, which provides superior protection against nature's elements.
When it comes to protecting your home, stucco is the preferred choice. However, plaster still has its own unique applications, particularly for creating decorative elements on walls, something that cannot be achieved with stucco.
Installation and Repair: How Labor-Intensive is it?
Both stucco and plaster installation require expertise due to the labor-intensive nature of the job. Stucco installation involves applying three layers over metal lath: the "scratch" coat, the "brown" coat, and the final "finish" coat. Synthetic stucco or EIFs may require additional layers compared to traditional stucco.
The process for installing plaster is similar, but not the same and we'll explain why in in a minute.
For repair projects, it is recommended to hire a professional. However, if you are dealing with a small hole or crack in the stucco, you can attempt a DIY repair if you have the necessary materials and tools. Otherwise, like I said it is best to leave it to someone experienced.
Installation Processes, Not the Same
The installation processes for plaster and stucco may seem similar since stucco is a specialized form of plaster as we mentioned previously. However, due to the construction of these materials, there are differences in their installation methods.
Plaster can be directly applied to surfaces, such as a masonry wall, to refresh its look. Yet, not all surfaces are suitable for plaster application. In cases where the surface is not conducive to adhesion, a fine wire mesh is used. This mesh is attached to the wall before applying the plaster.
On the other hand, stucco cannot be directly applied to walls because it will not adhere properly and may chip or break away. To ensure proper adhesion, a wire lath should be attached to the wall before applying the stucco.
It's important to note that the wire lath used for stucco is different from the fine wire mesh used for plaster. The stucco wire lath is made of thicker wire and has larger gaps between each wire.
Once the wire lath is in place, the stucco is applied in three coats or layers. The scratch coat provides a rough texture for the next coat to bond with, followed by the brown coat. Finally, the finish coat is applied to give the wall its final appearance.
Plaster vs Stucco: What Can You Create?
When it comes to exterior applications, plaster offers greater versatility compared to stucco. The reason behind this lies in the ability to pour plaster into molds, allowing for the creation of different designs like the popular and trendy California finish. By filling the molds with plaster, letting it set, and applying it to exterior walls, you can achieve unique and eye-catching designs.
On the other hand, stucco does not allow for this mold-based customization. However, it offers its own range of possibilities by allowing for various finishes. While stucco can only be applied to certain surfaces, it still allows for the creation of beautiful finishes.
Making the Choice: Plaster or Stucco?
To decide whether plaster or stucco is the right material for your home, there are a few questions to consider. As plaster is gypsum-based and stucco is lime-based, they possess different qualities and are used differently.
Plaster is the ideal choice for interior walls, while both plaster and stucco materials can work for exterior walls. The primary factor to consider between the two materials is the level of durability versus versatility you desire. In other words design vs durability.
It's important to note that both materials have slightly different installation processes. Regardless of your choice, it is recommended to hire an experienced contractor who can determine the best option for you based on your feedback, building construction, and weather. This will make it easier for you to make an informed decision.
Can You Install Stucco Over Plaster? The Million Dollar Question
Now let's discuss whether you can install stucco over plaster. ONLY If your exterior plaster walls are properly prepared, you can apply stucco over them.
The process involves cleaning the walls to remove dirt, dust, and grime that can accumulate over time. Remember, if not cleaned properly, the stucco will not adhere. Once the plaster is clean and dry, you can begin applying the stucco. It's important to ensure that the wall is completely dry to avoid future cracking or chipping caused by trapped moisture.
If you're looking for an alternative to plaster for your exterior walls, stucco is an excellent option and you can try multiple styles.
If you're still undecided between stucco and plaster, we encourage you to contact our stucco contractors. We will discuss your project and provide guidance on which option is better for you.
FAQs
Which is better plaster or stucco
Plaster and stucco are both durable finishes, but they have different qualities. Stucco is particularly well-suited for outdoor use since it doesn't usually require sealants or repainting once applied. It can also be used on a wider range of surfaces thanks to its smoother texture compared to plaster.