Plaster vs render: What’s the difference?

Key facts

• Plastering is used for interior wall and ceiling finishes, offering a smooth and versatile surface.
• Rendering is used for exterior wall finishes, providing durability and weather resistance.

Are you planning a home renovation and feeling overwhelmed by the choices for your walls? One common dilemma homeowners face is deciding between plaster and render. While both materials create smooth and even surfaces, they have distinct characteristics that make them suitable for different applications. 

This guide will help you understand the differences between rendering vs plastering, empowering you to make informed decisions for your specific needs.

What is plaster?

Plaster is a versatile material used to create smooth and even surfaces on interior walls and ceiling plastering. Plaster is typically made of gypsum, lime, or a combination of both. Plaster is applied in a wet form and dries to a hard, durable finish. Different types of plaster materials exist, including gypsum plaster, lime plaster, and veneer plaster, each with unique properties and applications.

Plaster is best suited for interior applications where a smooth and even finish is desired, such as living rooms, bedrooms, and hallways. 

What is a render?

Render, which is typically made from cement, acrylic, or polymer mixed with sand and other aggregates, is a durable, weather-resistant material used to create a protective and decorative finish on exterior walls. It is applied wet and dries to a hard, textured finish. The different types of render, each with unique properties and applications, include cement render, acrylic render, and polymer render.

Rendering in construction is best suited for exterior applications where durability and weather resistance are essential, such as external walls, fences, and facades.

Plastering vs rendering: Knowing the key differences

While both plastering and rendering create smooth and even surfaces, they differ significantly in their composition, application, and functionality. Understanding these differences is crucial in deciding whether you need plastering or rendering for your project.

In terms of cost

Plastering and rendering vary in cost depending on factors like project size, material type, and labour rates. Generally, plastering is more expensive than rendering due to the higher cost of materials and specialised labour required. However, rendering may require additional surface preparation, which can increase the overall cost of a rendering project.

For interior applications, plastering is the preferred choice despite the higher cost. For exterior surfaces and application, rendering offers a cost-effective solution without compromising durability and weather resistance.

Recommendation: Plastering for internal applications like interior walls, and rendering for exterior work.

In terms of material mixture and composition

Plaster and render have different material compositions, which affects their properties and uses. Plaster typically uses gypsum or lime as a binder, mixed with sand and other aggregates.

Gypsum-based plaster is commonly used indoors due to its smooth finish and quick drying time. Lime-based plaster is more suitable for older buildings and heritage restoration projects due to its breathability and flexibility.

Rendering materials, however, often incorporates cement, acrylic, or polymers as a binder, mixed with sand and other aggregates. Cement render is a traditional and cost-effective option, offering good durability and weather resistance. 

Meanwhile, acrylic render is more flexible and less prone to cracking, making it suitable for areas with movement or thermal expansion. Lastly, polymer render is a modern and high-performance option, offering superior adhesion, flexibility, and water resistance.

Recommendation: Gypsum plaster is best for interior walls due to its smoothness, while acrylic or polymer render is better for exterior walls due to its flexibility.

In terms of functionality and uses

Plaster and render serve different functional purposes in construction and renovation projects. Plaster is mainly used inside to create a smooth surface for painting or wallpaper, and to add decorative elements like cornices and mouldings.

Render is mostly used on exterior walls to protect and decorate them, and it also helps regulate the building’s temperature. Render is particularly useful for covering imperfections in brickwork or concrete surfaces or mending exterior walls’ cosmetic defects.

Recommendation: Plaster is best suited for interior applications where aesthetics and smooth finish are paramount. Render is ideal for exterior applications where durability, weather resistance, and thermal performance are essential.

In terms of maintenance and durability

Plaster and render each have different maintenance requirements and durability levels. It requires regular cleaning and occasional touch-ups to maintain its smooth finish and prevent cracking. Proper ventilation and waterproofing are crucial, as plaster is susceptible to moisture damage.

Conversely, render is more durable and requires less maintenance. It is resistant to cracking, weathering, and moisture damage, making it ideal for exterior applications. However, it may still require occasional cleaning to remove dirt and grime. 

Important note: Before undertaking any plastering or rendering work on older buildings, particularly those built from the 1930s to the 1970s, have the surfaces checked for asbestos. Consult a licensed asbestos professional if you suspect its presence.

Recommendation: Plaster needs frequent upkeep to preserve its appearance in interior applications; render is low-maintenance.

In terms of sustainability and environmental impact

Both plaster and render have environmental implications. Traditional plaster and render mixes can generate significant waste and have a high carbon footprint due to cement production. However, the industry is moving towards more sustainable practices.

Eco-friendly alternatives like clay plasters and lime renders are gaining popularity. These materials have lower embodied energy, are often locally sourced, and can be recycled. Some innovative products incorporate recycled materials or industrial by-products, reducing waste and environmental impact.

Proper application techniques can minimise waste, and some companies now offer recycling services for leftover materials. Additionally, well-maintained plaster and render can contribute to a building’s energy efficiency, potentially offsetting its initial environmental cost over time.

Recommendation: Consider eco-friendly options such as clay plasters and lime renders.

In terms of safety

Both plaster and render can be dangerous if not installed or maintained properly. Plaster is susceptible to moisture damage and can become slippery when wet, increasing the risk of falls. If the render isn’t applied correctly, it can crack and detach from the wall, which could injure people and damage the property.

Proper installation and waterproofing are essential for both plaster and render to ensure safety and prevent damage. It’s important to hire qualified professionals for installation and to follow safety guidelines during application and maintenance.

Recommendation: Both plaster and render require careful installation and maintenance to ensure safety.

Choose the appropriate finish for your project

Basically, deciding between plaster and render all comes down to what your project actually needs. Both techniques serve unique purposes, with plaster enhancing interiors and render protecting exteriors. 

To get the best results for your home extension or improvement project, consult a qualified plasterer or renderer who can assess your specific needs and provide expert advice tailored to your project. With the right application, you’ll achieve a stunning and durable finish that stands the test of time.

Ready to give your walls a refresh? Post a job on Oneflare and connect with top-rated plasterers or renderers to get the job done right and safely.

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FAQs on plastering and rendering

Which is better for my project, plaster or render?

The choice between plaster and render depends on your specific needs, project requirements and area to fix/improve. Consider the location, budget, desired finish, and maintenance requirements before making a decision.

Can I use render for interior applications?

Yes, render can be used for interior applications, but it may not provide the same smooth and even finish as plaster.

Can I use plaster for exterior applications?

No, plaster is not recommended for exterior applications as it is susceptible to moisture damage and cracking.

Which is more expensive, plastering or rendering?

Generally, the cost of plastering is higher than rendering due to the higher cost of materials and specialised labour required.