DIY: painting a room step by step (prep, filler, primer, two coats and ventilation)

Before you start, read the guide to paint types and sheens to choose the right paint, and the safety guide for using a ladder safely.

1) Choose the paint and work out the quantity

• Sheen: flat/matt hides wall imperfections and suits ceilings; higher sheens are easier to clean and suit hallways, high-traffic walls and kitchens1.
• Quantity: use the paint calculator, and take the coverage rate from the can of the product itself, as it varies from paint to paint.
• Low VOC: choose a low-VOC paint for closed rooms. See the paint guide.

2) Preparation (the most important stage)

1. Empty the room or move furniture to the middle and cover it, and cover the floor.
2. Switch off the circuit if you will remove switch and socket plates, then remove them and keep the screws in a bag.
3. Clean the walls of dust and grease (especially near the kitchen and light switches) and let them dry.
4. Fill holes and cracks with filler using the filling knife, and let it dry as the product instructs.
5. Sand the dry filler flush with the wall, then wipe off the dust.
6. Apply masking tape along ceiling edges, skirting boards, doors and windows.
7. Primer: apply it over filler and new surfaces, and over the whole wall if you are going from a dark colour to a light one.

3) Painting

1. Start with the ceiling if it is being painted, then the walls.
2. Cutting in: brush a 5–7 cm band along corners, edges and around switches.
3. Rolling: load the roller without dripping, paint the wall in sections about a metre wide with overlapping top-to-bottom passes, and blend each section into the previous one while still wet to avoid lap marks.
4. Second coat: after the drying time printed on the can.
5. Remove the tape at an angle after the last coat, before the paint fully hardens on the tape.

4) Ventilation and leftovers

The US Environmental Protection Agency recommends2:

• Increasing ventilation when using products that emit volatile organic compounds, and meeting or exceeding label precautions.
• Buying limited quantities of products used only occasionally, such as paints.
• Disposing of old, partly full containers safely, not with regular rubbish.

In practice: open windows and run an exhaust fan blowing outwards while painting and afterwards, and preferably nobody sleeps in the room until the smell has gone.

5) Cleaning up

• Water-based (acrylic) paints: wash tools with soap and water straight away.
• Oil-based paints: need a solvent (thinner) as the product instructs, with ventilation.
• Keep a small amount of paint in a sealed can labelled with the colour and room for future touch-ups.