how to fit plaster coving

How To Fit Plaster Coving – The Complete Guide

Plaster coving is often used to provide the finishing touches to a room. Coving is a decorative feature fitted to the top of the wall where it meets the ceiling.

Coving is often considered a period feature, although it does have a place in contemporary finishes also.

Coving, like this one from B&Q, comes in many different sizes and patterns, and you can buy coving in different materials, although plaster is the most common.

Plaster coving is usually purchased in pre-cut lengths, and you may be able to buy ready-made corner pieces to make fitting much easier.

You’d think it’s an easy job given you just glue it up, but it can be trickier than that. Our simple guide will help you get a professional finish when fitting your plaster coving.

Cost

Time

Difficulty


Tools & Materials

Tools

  • Cloth or sponge
  • Tape measure
  • Pencil
  • Sharp implement such as a putty knife
  • Mitre block or mitre saw
  • Saw
  • Sandpaper
  • Goggles and a dust mask (optional)
  • Step ladders

Materials

  • Coving strips
  • Adhesive

How To Fit Plaster Coving

Calculate how much coving you need

1. Do your sums

Use a tape measure to measure the length of each wall that requires coving. Add together the length required on each wall to get a total distance of coving required.

Now you’re going to work out how many of the pre-set lengths of coving you need. To do this you will need to know know how long each pre-prepared coving strip is, then divide the total length you require in your room by this length. You should then buy a few extra strips to be sure you have enough in that style. See the example below to work out the amount of coving strips you need to buy;

Say you have a room 4m x 6m, you will require 4m+6m+4m+6m = 20m of coving

The coving you require comes in 4m strips.

20m (of coving required) divided by 4m (length of strips required) = 5 strips required

I would then advise buying 2 extra, so purchase 7 strips in total.

Prepare the coving and area where you will fit it

Create guidelines and prep the area

Using a pencil, you're going to hold the coving in place and draw a pencil line around the edges of the coving so upon removing the coving piece you can see the area on the wall and ceiling which your coving will cover.

You can also now work out which pieces of coving you will cut to make it fit your room. When working out where the sections of coving will go, some may need trimming to fit in place. You can mark which pieces you will trim at this stage and make a note of how long you need each section to be.

Clean the area

You will need to prepare the area where you plan to install the coving to ensure it sticks properly. Remove any old wallpaper up to your pencil line. If you aren’t replacing the wallpaper or intending to repaint be careful to only work within your guidelines. You don’t want to damage the area that will still be seen underneath your coving.

Once you have tidied up the area, use a damp cloth to remove dust and dirt. If there is any leftover wallpaper paste on the wall where you’re fitting the coving, you should remove this to ensure you get the best adhesion. You may need to give this a scrub to thoroughly remove it.

Create a key

Use a sharp tool such as a putty knife to score the area you have marked out. By scoring the wall you're going to create a key and this will enhance the adhesion when you fit the coving. Give your wall and ceiling a final wipe over to remove any dust this step may have created.

Cut any corners as required

You may need to cut the coving to fit the corners of the room if you don’t have pre-cut corner sections. These pieces will need to be cut at an angle so that they fit together perfectly in the corners.

There are three main methods you can use to cut corners;

Using a mitre block

Cutting angles in your coving so that the two pieces join is most easily achieved using a mitre block, which will guide you in cutting the perfect angle.

If it’s a standard 90-degree angle corner, you should cut the coving at a 45-degree angle so that it fits together. If it’s not a standard 90-degree angle you can use an angle finder tool to work out what the size of the angle is. Once you know the size of the angle, divide this number in two and this is what angle you will cut using your mitre block.

Make sure you cut the angle with the coving facing the right way as you will cut the piece differently depending on whether it’s an internal corner or external corner.

Take a look at this video which will show you how to use a mitre block and which way to cut your coving.

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Pro Tip: When sawing the coving, use one hand to steady the coving whilst sawing with the other hand. You’ll find a crosscut saw with medium teeth and a rigid blade best for this job.

A mitre saw is another way to cut angles in your coving. Simply set the angle and saw! Check out this video, which will show you how to use your mitre saw to cut the angles you need.

How to cut if you don’t have a mitre block or saw

You will find it easier using a mitre block or saw, but if you don’t have one there is another way to cut angles in your plaster coving. You will need a pencil and tape measure and possibly a spare pair of hands!

Take a look at this video which explains how to cut an internal angle in your plaster coving without the use of a mitre block or saw;

If you have external corners to deal with, watch this video which explains how to cut the coving for an external corner without using a mitre block or saw;

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Pro Tip: Add a few millimetres when cutting external corners, take a few millimetres away on internal corners as it will improve the fit!

Cut any coving strips shorter as required

You may need to cut the lengths of coving you have to get a perfect fit for your room. As these pieces will form a straight edge, you need to cut directly across the pieces so that two pieces can be connected to form one longer section.

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Pro Tip: Cutting coving can produce a fine dust, so protect yourself with goggles and a dust mask. Vacuum the area afterwards to remove all the dust.

Finally, smooth the cut edge

You need to ensure the newly cut surface is smooth and free from any rough areas. Use sandpaper to rub down the freshly exposed cut edge and ensure it’s flat and smooth.

Fit the coving 

Where to start

Start in one corner with either your pre-made corner section or your newly cut corner piece. Ensure that it fits neatly into the corner.

How to apply adhesive and attach to the wall

You need to purchase a special adhesive designed for attaching coving. Be mindful of the weight of your coving and the strength of the adhesive. You can purchase adhesive in a powder form that you’ll need to mix, in a tub ready to apply, or in a cartridge gun ready to apply.

You should apply a thin and even layer of adhesive on the parts of coving that will touch the wall and ceiling. You need to also apply adhesive on the edges that will meet other sections of coving to stick the coving strips together. You can either apply directly if using the cartridge gun, or use a filling knife to spread evenly on the coving.

Place the coving in position and press it into place. Push along all parts of the coving to ensure it’s evenly secured to the wall.

You will have a little time to manoeuvre the piece into the right position. If any coving adhesive comes out when you attach it, wipe it up quickly with a wet cloth before it has time to dry and ruin the finish.

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Pro Tip: Have a few wet rags handy, the last thing you want to do is be struggling up ladders, and only having one cloth which is already covered in adhesive.

To make sure it doesn’t move before it’s fully set, hammer nails in just underneath the coving to support the weight of the coving.

If this isn’t ideal, for example, you don’t want to ruin the paint or wallpaper underneath, you can hammer nails through the coving to support it whilst it dries. Don’t hammer all the way through, as this will make removing the nails more difficult. When it comes to removing the nails you can fill the holes as needed.

Finish the corner and move on

Now you have one corner piece in place you will fit the second piece to complete the corner by repeating step 2.

Once this is done, work your way around your room fitting one piece at a time and securing it with nails to allow the adhesive to dry.

Remove nails and fill

You can remove all nails once the adhesive is dry and the coving is secure. You can fill any gaps or imperfect joins with filler.

To finish the job

Check over your work, make sure any imperfections are blended with filler, all nails are removed and any excess adhesive is wiped away.

Complete the finish

Paint or finish to match your room

Many like to leave the coving with a white finish [which it typically comes in), however, it can add flair to your room if you paint it a different colour, or you can make it match by painting it the same colour as your wall or the ceiling it’s attached to. You may also have door architraves which you want to match your coving to, and you could paint these a similar colour.

Check out this video on the best way to paint your coving;

The most tricky part of the job, I find, is cutting the corners. Once you’ve mastered this part it’s not too difficult.

Coving is a great finishing touch to your room or a way to add a feature, and given it’s not too expensive or difficult to fit, it's a simple way to update your decor.

I'd love to hear from you in the comments below if you found this guide useful and managed to put these steps into action. As always, please remember to share if you think your family and friends will find this guide useful.
how to fit plaster coving

About the Author Hannah

I live in Manchester, UK with my young family, 2 cats and a crazy dog. I’m passionate about Victorian houses, Pinterest, Kevin McCloud and creating a home that’s beautiful yet practical for our family!