When starting the project of painting a room you should ideally paint the ceiling first. This avoids getting paint on the walls or woodwork. Start by either moving furniture out of the room or in to the middle of the room and cover it with a dust-sheet.
Your ceiling can be painted using either a brush or a roller, however as the area is large the most frequent way is to ‘cut in’ the edges and finish the job with a roller.
Load on the paint and use the brush on its edge to work along the outside of the room using long sweeping movements to produce a smooth line. The easiest way to hold your brush is by using a pencil grip, as this gives you extra control of the movement. You should aim to keep the bristles at a slight angle to the edge so that the paint flows as smoothly as possible.
After you have ‘cut in’ and whilst the line is still wet, start painting the ceiling with your roller. You need to make sure it is still wet otherwise a clear line will form between the edge of the wall and the centre of the ceiling.
Dip the roller into the paint tray and roll it firmly up and down to spread the paint evenly across the roller. Be careful not to apply too much paint as this will cause it to spray paint everywhere as you roller.
Next, create zig zag lines or a W motion, covering the ceiling lightly with paint. Every time you dip the roller in more paint move to an unpainted area and work back to overlap previous strokes and blend in the wet edges. Paint the ceiling in sections until it is entirely covered.
Then, if necessary you can go over the ceiling with your roller giving it a second coat in straight lines which will help even out the paint.