Plaster Coving: Everything You Need to Know

What is plaster coving?

Considered the most traditional type of coving as well as the most durable, plaster coving is the decorative join that links the ceiling with the wall. Also known as a ceiling cove or ceiling moulding, coving is mostly found in Victorian and Georgian properties and provides character to a property. There are three primary materials that coving is manufactured from.

1. Plaster: It is heavier than duropolymer and polystyrene coving. Plaster and plasterboard coving also require less maintenance. 
2. Polystyrene: Considered to be the cheapest coving option, polystyrene is the least durable and lightweight.
3. Duropolymer: This type is quicker to install and shares the same benefits as plaster coving, as well as being lightweight. 

Can you use paint on plaster coving? 

The simple answer is yes, you can use paint on plaster coving to create a more decorative coving design. But it is best practice to wait at least 24 hours after adding the plaster coving before you begin painting. This is so the coving and adhesive have time to bond. Before you put paint to brush, use a primer and then cover the coving with a matt emulsion paint. 

Difference between plaster coving and plaster cornice

When you are thinking about wall-coving ideas for your home or workplace, it is important to know the differences between coving and a cornice. Although both are installed as a wall and ceiling border, the 2 are opposites in their designs and patterns. 

Coving

• Usually, a simpler design compared to cornice mouldings - they are typically created with a ‘C’ shape or quarter circle profile.
• Coving details are dependent on personal preference and cost. For example, simple C-shaped coving designs were used in post-war times because of their clean appearance. Also, the uncomplicated designs could be mass-produced in gypsum plaster mouldings.
• There are different plaster coving sizes - the typical size you will see is 127mm. This measurement is not the height or projection - it corresponds with the imaginary diagonal straight line touching the ceiling to the wall. Other measurements such as 150mm and 100mm were also common from the 1930s. 

Cornice

• Typically less uniform, cornices are decadent and ornate, but the drop and projection could be the same dimensions as coving. Cornices are flexible with their patterns and can change depending on architectural trends. For example, you can buy cornices with small beads in their design - something to think about when coming up with cornicing ceiling ideas. 
• Because cornices can be different in patterns and designs, it is difficult to pinpoint the era when a cornice was produced. Designs and profiles can even depend on the cornice region.
• To differentiate between designs, Georgians preferred square pattern details on cornices. Whereas Victorians opted for fleur-de-lys patterns, also known as ‘egg and dart’ patterns, with dentils carved in the designs. 

Advantages and disadvantages of plaster coving

• Plaster coving is a more traditional coving material and is considered the most attractive choice. It is great value for attractive and large profiles and there is a bigger selection of profiles to choose from. You can create a more unique and authentic period-style finish. 
• Although plaster coving is a hard material, it can also break easily and is quite brittle. Because of this, it is advised that 2 people are present for the installation - especially if you are attaching coving to an artex ceiling as its texture can prove to be tricky.
• Plaster coving has a smooth and bright finish compared to polystyrene and duropolymer. Therefore, it requires less paint for an even finish. 
• Plaster coving is generally more expensive. However, particularly for awkward angles and areas, plaster coving will be your best option as it is much more flexible. 

Cost of plaster coving

The below table outlines the estimated costs you will need to consider, including labour costs.

How to fit plaster coving

For those who are less experienced in decorating and building projects, it is best to hire a professional. But if you are confident in your DIY skills, fitting plaster coving by yourself is certainly a viable option. Here are the 7 steps to follow when measuring, cutting and fitting plaster coving. 

Step 1 - Prepare your materials

Before you go ahead and start the project, be sure to collect all the materials and tools you will need. This is a list of what you will need to complete the job.

Step 2 - Measure the coving

When measuring the coving, be sure to read the manufacturer’s instructions and check how far the coving edges should be fitted from the ceiling and wall. The measurements will depend on the sizes and style of coving. At 500mm gaps, you will then need to draw pairs of marks on the ceiling and walls. These will work as your coving guidelines. With a spirit level, join the marks together so you are left with 2 level pencil lines - one on the ceiling and another on the wall. 

Step 3 - Coving corner

Depending on the dimensions of the room, you may need to cut coving corners. Measure up the coving and mark out the measurements you will need, keeping external and internal mitre cuts in mind. On the coving face, be sure to mark out the direction of the cuts. A tip for when you are cutting: with an external corner, the wall face is the shortest end. For the internal corner, the wall face is the longest end. To cut the corners, place the coving in your mitre box - the wall edge needs to be at the top of the box. Make a 45-degree cut at each end with a fine-toothed panel saw. Once complete, you may need to sand the ends down for a smooth finish. 

Step 4 - Start fitting

Start on the longest wall first. Hold a cut piece of coving in its position and check if the size is right for the space. Just before you attach the coving, make sure the area is clean from any dust. Use coving adhesive on the area and let it dry first before you add coving to newly-applied plaster. Make sure to score the area before the coving goes on - this allows the adhesive to bond securely. 

Step 5 - More adhesive

Fix a generous amount of plaster coving adhesive on the bottom and top edges of the coving. Be sure to apply enough so it oozes out of the tube. It will help to cover small gaps that appear. Then, line up the coving to the markings on the ceiling and wall, pressing the coving firmly down. 

Step 6 - Further protection

At 600mm gaps, hammer some panel pins into the coving. This will add more security so the adhesive can be properly set. Once the adhesive has been set, you can remove the panel pins. For longer walls where two coving pieces have to join together, you should use matching mitre cuts and apply adhesive to the coving ends. The adhesive will hold the two pieces together. 

Step 7 - Final touches

When looking over your work, use a bit more adhesive to fill in any little gaps between adjoining pieces of coving. If there are any gaps between the coving and the wall or ceiling, use some extra adhesive for this too. Then, with a scraper, be sure to remove the excess adhesive and wipe with a damp cloth. 

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