The secret to successful ceiling painting is in the preparation. Ensure that all remaining paint on the ceilings is sound, with a good bond to the surface above it. Remember, the more paint that is applied to ceilings, the heavier the weight and the more likely it is to fail.
Start by sanding the entire area, thus improving the bond for the next coat. Areas of old mould should first be painted with a coat of universal undercoat, or if it’s very badly stained, a coat of road marking paint will obliterate the old stains.
Once dry, sand again and apply your normal coatings. Special paints are available for bathrooms, so visit your paint store and ask for advice. To find a really smooth ceiling is a rarity, so stick to flat paints with little or no sheen, as the higher the sheen the more likely it is to show up imperfections. The same applies to painting walls.
If the paintwork is in good condition, you may only need to clean it down, using cold water, a clean cloth and a bar of Sunlight soap, which will do a lot less damage to the paint, than household cleaners which tend to include some form of abrasive. Try this out on a section of wall which you are going to repaint; you will see the sheen disappear from the paint if the wrong cleaning agent is used. One method for testing paint is the scrub test: A scrubbing brush is mechanically rubbed over a painted surface and the paint is monitored to see how many times it is “scrubbed” until it breaks down. The higher number of scrubs the better the quality of the paint. Check the quality of the paint you are going to wash/clean as the lower the quality, the more likely it is to break down.
While you are painting the ceiling, don’t forget to seal up around the cornices as they often tend to move away from the wall slightly. If you do not have a good relationship with ladders, attach your roller to the end of a broomstick or pole, so you can paint with your feet firmly on the ground.
Don’t forget the protective gear to protect your head and hair from paint drips. If you are venturing up a stepladder, make sure that it is in good condition. - Weekend Argus