Ceiling Cornice and How to Fit It
As with all decorating operations, time and care spent on planning will pay off later, helping you make sure of a successful result. To judge the optimum coving depth before buying, cut a paper template to a likely depth and a length of 1.5 to 1.8m (5 to 6ft) and pin it in the angle between the wall and ceiling where the coving will go. This should be long enough for you to gain an idea of the finished effect. If it seems wrong, (ie, too shallow or too deep), repeat the operation with a template of a different depth until you have the right size.
Having decided on the depth of the coving, the next step is to measure up the ceiling accurately. If it is going to be a difficult shape to deal with — for example, if there is a chimney breast or corners which are out of square — make a scale plan of the ceiling on squared paper. This way you will be able to work out exactly where the joins will come in the lengths of coving and where you will need to cut or mitre the coving for the corners. Use your plan or measurements as a guide for ordering the correct amount of coving.
A ceiling centre is going to be a focal point of interest, and it is essential therefore to choose one which is the right size for the room. They range in size from 150mm (6in) to 685mm (2ft 3in) in diameter; smaller ones suit smaller rooms and larger ones large rooms. To help you decide on the size of the ceiling centre, you can again make a paper template to gain an impression of the finished effect.
Marking up and preparation
You will need to mark guidelines for fixing the coving. You can use a piece of coving to indicate where lines should be drawn at the correct level on wall and ceiling.
The surface must be properly prepared. You will need to make sure all old wallpaper, flaking paint or distemper is removed from between the guidelines. It is also advisable to fill any cracks. Leave theto harden and then, if necessary, sand smooth. Bumpily filled cracks could throw the coving out of alignment, making it look distorted. With some types of you will also have to provide a key, so the grips properly, by slightly roughening the surface of the wall and ceiling where the coving will be fixed.
For a ceiling centre you can cut a paper or cardboard template round which to draw a guideline before preparing the surface in the same way as preparing for fixing coving. Make the template slightly smaller — by about 6mm (1/4in) — than the actual ceiling centre so areas where paper or paint have been removed will not show when the ceiling centre is in place.
Measure the coving for length. Remember that corners will have to be mitred and that there is a different technique for internal and external angles. Some preformed coving comes with a special template provided in the pack to make cutting and mitring easier — you place the template on the coving and trace me required mitre shape with a pencil. If you are using coving which does not have such a template provided, you will need to make up a mitre box which you can use to hold the coving while you cut it at the correct angle. For cutting you will need a fine tooth saw and you should cut from the face of the coving to ensure you get a clean edge.
A plaster/gypsum adhesive will have to be mixed according to the manufacturer’s instructions. If the job is likely to take a while, mix up only part of the adhesive at a time so you don’t waste any if it dries out too soon. With some types of adhesive you will need to dampen the surface to be coved with water. If the surface is very porous you will have to seal it with a coat of diluted emulsion or PVA adhesive first.
You can then spread out the adhesive onto the back edges of the coving. Push each length firmly into position and hold it in place until it sticks. If you are using a contact adhesive, spread it on the back of the coving. Press the coving in position, then pull it away immediately and leave for about 10-20 minutes — the honeycomb structure of the adhesive will be on coving, wall and ceiling surfaces. Then fix the coving back in position and adjust its positioning at once as the adhesive will harden quickly and will be firmly bonded within an hour.
Heavier covings may have to be nailed or screwed, as well as stuck, into position. You should use galvanizedor rustproof spaced 500mm (20in) apart, and, so they won’t be visible on the finished surface, punch the nails below the surface with a nail punch, or countersink screws and fill the holes you have created with surplus adhesive or with cellulose .
Scrape off surplus adhesive which squeezes out from under the coving. (Sometimes this can be used to fill nail holes and gaps. Otherwise, you will have to use a cellulose filler).
Fixing ceiling centres
Ceiling centres are fixed in the same way as coving. Heavier types may need extra support from nails or screws: make sure the heads are countersunk or punched home and fill the gaps with adhesive or other filler.
If the ceiling surface is bad and you want to use a textured paper to help disguise this, it is easier to paper the ceiling first and then cut out the area to be covered with the ornament rather than fixing the ceiling centre and then papering round it.
Where a ceiling centre is to be used to enhance a central light fitting, you will also have to cope with the electrics. As a first step, you will have to remove the existing bulb and lampholder. Where the ceiling centre has a hollow in the middle, it may be possible to leave the existing ceiling rose in place and fit the new ceiling centre over it. Simply pull down the flex through the hole in the middle of the new centrepiece (some already have holes bored; with others you may have to make the hole).
With other types of ceiling centres which are flatter in the middle, you may have to remove the existing rose and replace it with a terminal connector strip which will fit in the Space available before fixing the new ornament. Both these solutions have the disadvantage that if at a later date you wish to gain access to the, you will have to remove the ceiling centre. As an alternative you can rewire the light so access can be gained from above.
If you have a very heavy chandelier, it may be necessary to have a hook to support it — coming through the hole in the middle of the decorative centre — and this will have to be fixed to a beam or joist to take the weight. This may also determine the position of the fitting, since there may not be a conveniently placed central support.
If you intend painting the ceiling, emulsion paint, which can be applied without silting up any of the more decorative mouldings, is particularly suitable. A matt or eggshell lustre-finish oil-based paint can also be used, but this is not very suitable for delicate mouldings. Lastly, you can use multi-purpose paint (ie one which can be used on walls, ceilings and woodwork). Gloss and other solvent-based paints should never be used on plastic.
Colour is a matter of personal choice but usually the ‘bed’ — the flat part of the ceiling — looks best in a colour which can be dark, rich or strong if the room is fairly tall and paler if it is low. The relief decorations can be picked out in white or any other contrasting neutral shade, or in a pale, toning or contrasting colour. Give the ceiling decorations their first coat, then paint the ceiling itself with two coats, taking particular care at the edges and where it meets the ornaments. Apply a final coat to the decorations.