When it comes to finishing off the look of a room, coving can make all the difference. Coving not only enhances the architectural detail of your interiors but also helps to create a smooth transition between the walls and ceiling. However, when choosing coving, homeowners and interior designers often find themselves stuck between two popular materials: plaster and polystyrene.

Each has its own set of pros and cons, making the choice dependent on factors such as budget, desired aesthetics, ease of installation, and long-term durability. This guide compares plaster vs. polystyrene coving to help you decide which is the better option for your space.

What Is Coving?

Coving is a type of decorative moulding that is installed at the junction between walls and ceilings. It can be simple or ornate and is commonly used to soften the sharp angle between wall and ceiling while adding character to a room. Coving is available in a variety of styles, from traditional Victorian to minimalist modern, and is made using different materials — most commonly plaster and polystyrene.

Plaster Coving: A Classic Choice

Pros:

Elegant and Authentic Appearance
Plaster Coving offers a timeless, elegant look and is especially well-suited to traditional or period properties. The material allows for intricate detailing and sharp lines, ideal for ornate mouldings.

Strong and Durable
Plaster is a robust material that can last for decades when properly maintained. It’s resistant to warping and handles knocks better than its polystyrene counterpart.

Paint-Friendly Surface
The surface of plaster coving accepts paint beautifully, often requiring fewer coats for even coverage.

Cons:

Heavier Material
Plaster is significantly heavier than polystyrene, making it more challenging to handle and install. It often requires two people and professional skills to install correctly.

Higher Cost
Due to the materials and labour involved, plaster coving is generally more expensive. This may not be the best choice for budget-conscious projects.

Brittle Nature
Despite its durability once installed, plaster can be brittle and prone to chipping or cracking during installation or transport.

Polystyrene Coving: Lightweight and Modern

Pros:

Lightweight and Easy to Install
Polystyrene coving is extremely light, which makes it easy to cut, handle, and install — even for DIY enthusiasts. Most types can be installed with adhesive alone.

Budget-Friendly
Polystyrene coving is much more affordable than plaster, both in terms of materials and installation costs.

Versatile Designs Available
While not as finely detailed as plaster, modern manufacturing techniques have improved the design quality of polystyrene coving, with options that mimic traditional plaster quite well.

Cons:

Less Durable
Polystyrene is more prone to dents, warping, and damage over time, particularly in high-traffic areas or if not installed properly.

Lower-End Look
While suitable for many modern homes, it may lack the authenticity and crisp detail needed for high-end restorations or period properties.

May Require More Painting Effort
Polystyrene can be slightly more absorbent and textured, often requiring more prep and paint for a smooth finish.

Which One Should You Choose?

Choose Plaster Coving if:

  • You’re restoring a period property or aiming for a traditional look.
  • Budget is less of a concern.
  • You want intricate, high-end detail and long-term durability.
  • Professional installation is part of your plan.

Choose Polystyrene Coving if:

  • You’re working on a modern home or a DIY project.
  • Budget and time are limited.
  • You prefer lightweight, easy-to-install materials.
  • You don’t require highly detailed finishes.

Final Thoughts

There’s no one-size-fits-all answer to the plaster vs. polystyrene coving debate. Both materials offer unique advantages and disadvantages that can significantly influence your final decision. If you’re after luxury, intricate design, and timeless appeal, plaster is the way to go. However, if ease, affordability, and convenience are higher on your list, polystyrene is a smart, practical choice.

By weighing these factors carefully against the specific needs of your project, you’ll be better equipped to make a decision that enhances the overall aesthetic and function of your space.