Location: Southampton, South East.
Adding plaster coving around a bay window is a great way to not only highlight an impressive feature but also elevate your home. A sleek transition from wall to ceiling or an intricate intentional feature. Adding plaster coving will add character, sophistication and luxury to both period properties and newer homes. Just like cutting internal or external corners cutting coving at none 90° is a straight forward process when done professionally.
We are often asked if our plaster coving can be fitted around bay windows, where the angles are not 90 degrees. The answer is yes, but it requires the skill and experience of professional coving installers. In the images below, we show how plaster coving is fitted around a bay window for a customer in Southampton.

Our customer was especially pleased with the result, as before they contacted us, they had been informed that it was impossible by several builders. In reality, the job required an experienced coving specialist with the right expertise.
So if you are told by a builder that plaster coving cannot be fitted in your home where you want it, it is worth getting a second opinion. We have contacts for countless reliable and experienced cornice fitters who we can easily put you in touch with. Our recommended fitters will always be able to do the work you require.

1. What You'll Need:
It's best to consult with your fitter what materials and tools they will require, in most cases a coving specialist will supply the following as part of the service.
- Plaster coving lengths, this customers went with our LPC017
- A sharp fine tooth saw
- Adhesive
- Casting Plaster (for screw holes and any gaps/edges)
- 50mm Dry walls screws
- Tape measure & pencil
- Sand paper
- Paint (to finish)
2. Measure Out the Bay Window Accurately
Each wall segment should be measured individually to ensure accurate coving segments. using a tape measure, measure each section of the bay window in millimetres.
3. Cut Coving to Match Non-90° Angles
Using a protractor or angel tool, measure the corner of each angle and divide it by 2, for example if the corner is 120° the angle you will cut at is 60°. For external corners angles should be cut outwards and for internal corners you should cut inwards.
4. Dry Fit the Coving to Confirm the Angles
Position each section of coving against each angle on the bay window on the ceiling on wall to check they fit. Don't worry if they don't join up like a jigsaw, small gaps will be filled and finished later with casting plaster.
5. Apply Adhesive and fix in place
apply adhesive and screw in place using 50mm dry wall screws, we recommend using one screw per meter in a zig zag motion. The dry wall screws provide extra support whilst the adhesive dries.
6. Fill caps and Screw Holes Seamlessly
Mix the casting plaster following our guide and fill all caps, screw holes and edges. Our installation tolls are ideal for achieving the best finish.
7. Sand and Prepare for Painting
Once the casting plaster is fully dry, gently sand all edges and corner, if you are using a more ornate style it is important to be extra gentle and careful to not over sand.
8. Finish with Paint
Once you are happy with the finish and when the coving is clean and smooth, the coving is ready to be painted. Matt emulsion is best to achieve a seamless finish as it helps hide imperfections, whereas eggshell provides a more durable and washable finish (ideal for kitchens)

An already impressive feature in the customer's property, the bay window is now beautifully framed by our LPC017. The room now has a more built-in polished look with better visual flow and continuity.

Plaster Coving for Bay Windows – Frequently Asked Questions
Can plaster coving be fitted around bay windows?
Yes, plaster coving can be fitted anywhere between walls and ceilings to add architectural detail. With bay windows specifically the only thing you should be careful of is choosing the correct size, choose a style that will fit in the space between the window and ceiling.
Do I need a professional installer to fit coving around a bay window?
We would recommend you use a professional to fit plaster coving, a professional will be able to solve common issues such as uneven walls and ceilings easily. More finishing is required when fitting coving around a bay window and a level of craftsmanship is required. If you would like us to put you in touch with one of our fitters in your area, please contact us.
What is the best coving for bay windows?
Instead of thinking about whats the best coving for a bay window, think about your favourite style or the period of your property and pick based on that. Any coving style from our collection is suitable for bay windows.
What angle should coving be cut for non-90° corners?
If you don't have a digital tool, set a sliding bevel to match the corner so each side sits flat against each wall, trace it onto paper, measure the angle with a protractor, then divide it by two for your cut. For example is the angle is 170° you should cut at 85°.
Is plaster coving suitable for modern homes with bay windows?
Yes, coving is suitable for all homes and all properties both old and new. Plaster coving is the easiest way to elevate any interior. Could you imagine a room without skirting boards or architraves? We couldn't imagine one without coving.
How much does it cost to install coving around a bay window in the UK?
Costs vary from project to project, depending on your specific requirements. Before requesting a quote, you should decide on the size of the coving and the level of detail along with the required meters, this will help an installer provide you with an accurate quote.