How many coats of paint should a painter apply?

Coats are where painting quotes differ invisibly. The finished job looks the same on handover whether it received one coat or two. The difference appears in three or four years.

The standard

• Bare or patched substrate: a primer or sealer appropriate to that substrate, then two top coats.
• Repaint over sound existing paint in a similar colour: two top coats.
• Significant colour change, especially dark to light: primer plus two coats, sometimes three.
• New plasterboard: a dedicated sealer, then two coats. Skipping the sealer causes patchy sheen that cannot be corrected without redoing it.

Primer is not optional filler in a quote

Different substrates need different primers, and using the wrong one, or none, is a leading cause of early failure. Bare timber, bare plaster, rusted metal and previously oil-painted surfaces all have specific requirements. A quote that mentions no primer at all on a job involving any bare substrate is describing a shortcut.

Where the money actually is

On most jobs, preparation is more than half the labour and paint is a minority of the cost. That is why a dramatically cheaper quote is almost never cheaper paint. It is less preparation, or fewer coats, and both are invisible on the day you pay.