Can You Paint Over Gloss Paint Without Sanding?

New paint needs something to grip. Gloss is smooth and hard, so most paint won't stick well unless the surface is 'keyed' – lightly roughened. Sanding is the usual way to do this. There are alternatives – liquid sanders/deglossers and specialist adhesion primers – which can reduce or replace sanding in some cases.

Sanding creates tiny scratches that the new paint can bond to. It also removes dirt and shine and smooths out drips and bumps. Without it, paint applied over gloss can scratch off with a fingernail or peel away in strips.

Liquid sanders (deglossers) are wiped onto gloss to chemically dull the surface. They can be useful on intricate mouldings, but they're not as reliable as a mechanical key. Adhesion primers are designed to stick to difficult surfaces and can be used over gloss. Some 'one-coat' or 'multi-surface' paints claim to stick without sanding – but results vary.

Most decorators still give gloss a light sand, even when using an adhesion primer.

If your existing woodwork is oil-based gloss and you want to switch to water-based satin, you need a good key and usually a suitable primer. Water-based paint applied directly over oil-based gloss without preparation may not adhere properly.

Our guide to water-based vs oil-based paint explains the differences.

In older houses, old gloss may contain lead. Don't dry sand it. Use wet abrasives or other safe methods, and test first if you're unsure. See our guide to lead paint and Artex.

A professional will clean the woodwork, lightly sand it, remove the dust, and then apply undercoat or primer if needed followed by the top coat. It adds time, but the result is far more durable. If you're getting woodwork painted, see our guide to the cost of painting doors and skirting, and get quotes from local decorators.