How to Prepare Walls Before Painting: What a Professional Actually Does

Ask any decorator what separates a lasting job from a disappointing one and the answer is the same: preparation. The painting itself is often the quickest part of the day. What happens before the first coat decides whether the finish looks sharp for ten years or starts to fail in two.

Here is what a professional actually does, in roughly the order they do it.

1. Clear and protect

Furniture moves out or into the centre of the room under dust sheets. Floors are covered with proper dust sheets, not thin plastic that slips. Sockets and switches are unscrewed or masked, and radiators may come off the wall for a clean result behind them.

It sounds mundane. It is also what stops paint spatter on your carpet.

2. Look hard at the surface

A good decorator walks the room with a torch held low against the wall. Raking light picks out dents, ridges, hairline cracks and patches of different texture. These are the things that will show up under a coat of paint, and the sheen you pick will make them worse. Our guide to choosing the right paint finish explains why.

3. Deal with damp, mould and stains first

Any damp patch or mould gets investigated before it gets covered. If there is a cause, such as a leak or condensation, that is fixed. Our article on condensation and mould sets out the order of work.

Stains from water, smoke or nicotine need a stain-blocking primer. Ordinary emulsion lets them bleed through within hours.

4. Strip what is failing

Loose or flaking paint is scraped back to a firm edge. Old wallpaper is stripped, with steam or a scoring tool and warm water. Peeling lining paper is taken off rather than painted over.

In an older house, the age of the paint matters before any scraping begins. See our guide to lead paint in older homes.

5. Fill and repair

Holes, dents and cracks are filled. The filler goes in slightly proud, left to dry fully, then sanded flush. Deep holes are built up in layers because a thick single fill shrinks and cracks.

Bigger problems, such as loose plaster, blown patches or damaged cornice, are repaired properly rather than papered over. We cover that kind of work under coving, cornicing and plaster repair. Decorative finishes are a separate skill, and our Venetian plaster guide explains what is involved.

Cracks along joints and where walls meet ceilings get flexible decorators’ caulk, not hard filler, so they can move with the building.

6. Sand

The whole surface is lightly sanded. This removes ridges and gives the paint something to grip. On woodwork it dulls the old gloss and smooths brush marks. Dust is then wiped off with a damp cloth, because paint over dust ends up gritty.

7. Prime and seal

This is the step amateurs most often skip. New plaster needs a thinned first coat, called a mist coat, so it does not suck the moisture out of the paint. Bare wood needs a primer, and knots need sealing so resin does not leak through. Filled patches are spot-primed so they do not look dull against the rest of the wall.

Primer is not an expensive extra. It is the reason topcoats look even.

8. Cut in and roll

Only now does the finish paint come out. The edges are cut in with a brush, and the main area is rolled. The two are done together while the edges are wet, which prevents the visible frame effect that appears when brushwork dries before the roller catches up.

9. Allow proper drying time

Each coat is left to dry according to the tin. Rushing the second coat over a tacky first one gives streaks and poor adhesion. In cold, damp weather, drying times stretch.

10. Final checks

Once everything is dry, the room is inspected in daylight and artificial light. Touch-ups are done, masking removed carefully, and the room is cleaned up.

Why it adds time and cost

Preparation often takes as long as the painting, and sometimes longer. That is why a very cheap quote that skips it can end up costing you more. For a realistic idea of how prices work, see painting costs in Bury St Edmunds.

If you would like a job done in the right order, with the preparation included, our team handles interior painting and decorating across West Suffolk. You can request a free quote any time.