Good surface preparation is the single biggest factor in how long paint lasts: clean off grease and dirt, treat any defects, prime, and only then paint — in that order, on every surface. Most paint failure is a prep failure, not a paint failure. This guide sets out the preparation sequence for walls, metal, concrete, wood and roofs, and points you to the right products at each step, starting with cleaning using All-Rite or Industrial Degreaser.
Why does surface preparation matter so much?
Paint can only bond to a surface that is clean, sound and dry — grease, dust, flaking material or moisture underneath will make even the best coating peel. When a new coat lifts within months, the cause is almost always something left on or wrong with the surface, not the paint itself. Preparation removes the contamination and weak material the paint would otherwise grip, and creates the clean, stable base a coating needs. Time spent on prep is never wasted; it is the difference between a finish that lasts years and one that fails in a season.
The universal preparation sequence
Every job follows the same order: clean, repair, prepare the profile, prime, then topcoat — the surface and products change, the sequence does not. First you clean off grease, dirt and loose material. Then you repair cracks, holes or rust. Then you prepare the surface so the coating can key to it — sanding, etching or abrading as needed. Then you prime, and finally you apply the topcoat. Working out of order, such as priming over grease or painting over a crack, is what causes coatings to fail.
| Step | What it does |
|---|---|
| 1. Clean / degrease | Removes grease, dirt, hand marks so paint can bond |
| 2. Repair | Fixes cracks, holes, rust, damp before coating |
| 3. Prepare profile | Sand, etch or abrade to give the coating a key |
| 4. Prime | Seals and bonds; the right primer for the surface |
| 5. Topcoat | The finish coat, applied to a sound base |
How do you prepare walls before painting?
Wash the walls to remove dust, grease and hand marks, fill cracks and holes, sand smooth, then prime bare or repaired areas before painting. Cleaning is where sugar soap has traditionally been used; a modern water-based cleaner such as All-Rite Multi-Purpose Cleaner does the same job and rinses cleanly. New plaster must cure and be sealed with a plaster primer; chalky or previously painted walls need the right undercoat. See the interior wall paint guide and the plaster primer guide for the correct primer.
Is sugar soap necessary, and what can you use instead?
You do need to clean walls before painting, but you do not have to use sugar soap specifically — any effective, rinse-clean cleaner that removes grease and grime does the job. Sugar soap is the traditional South African choice, and it works, but it can leave a residue if under-rinsed. A biodegradable water-based cleaner like All-Rite is the modern alternative: it lifts grease and hand marks, rinses without residue, and is gentler to handle and safer around the home. Whatever you use, always rinse and let the wall dry fully before priming or painting.
How do you prepare metal before painting?
Degrease the metal, remove all rust and loose old paint, then apply the correct metal primer while the surface is clean and dry. Start with solvent Industrial Degreaser to strip mill oils and grease — new galvanised steel especially must be degreased. Then treat rust, prime, and topcoat. Confirm the surface is grease-free with the water-break-free test before priming. The full metal system, including which primer for galvanised, mild steel or rusted metal, is in the metal paint guide.
How do you prepare concrete and floors?
Degrease to remove oil, repair and etch the surface to open the pores, then apply the floor coating or sealer once the concrete is clean and dry. Oil in concrete must come out first — see how to remove oil stains from concrete. New concrete needs to cure and be etched so the coating can key. For the coating options and full method, see the floor paint guide and, for paving and outdoor stone, the stone sealer guide.
How do you prepare wood and roofs?
Wood must be clean, dry and sanded before sealing or painting; roofs must be cleaned of dirt and treated for rust or moss before coating. For timber, clean off grime, sand back, and apply the right sealer or wood coating — see the wood care guide. For roofs, wash off dirt and algae, treat rusted metal sheets or bind chalky tiles with the correct primer, then topcoat — see the roof paint guide. The principle is identical: a clean, sound, dry surface first.
How do you know the surface is ready?
The surface is ready when it is clean, sound and dry: no grease (confirmed by the water-break-free test on metal and concrete), no loose or flaking material, no damp, and any repairs cured. On metal and concrete, wet the surface and check the water sheets evenly without beading. Press on old paint to check it is well stuck. Make sure fillers and primers have dried or cured for the time on the label. Only when all of that is true should the topcoat go on. See the cleaning options in the degreaser guide.
