Costs · 4 min read · Updated 6 November 2026
Clean, repaint or re-render? What tired render really needs
Start with the condition, not the colour
Render that looks tired can be suffering from very different problems. Green and black staining is usually surface growth. Fading, chalking and peeling are paint problems. Cracking, bulging and hollow areas are problems with the render itself. Each has a different fix and a very different cost, so it is worth checking what you actually have before getting quotes.
Quick diagnosis
| What you see | Likely cause | Usual fix |
|---|---|---|
| Green, black or orange staining | Algae, mould, lichen | Soft wash |
| Dirty streaks below sills | Run-off and dirt | Soft wash, fix drips |
| Chalky powder when rubbed | Weathered paint | Clean, then repaint |
| Peeling or flaking paint | Failed paint, damp behind | Repair cause, prepare, repaint |
| Fine hairline cracks | Normal movement | Fill or paint with flexible coating |
| Wide cracks, hollow sound, bulging | Render debonding | Repair or re-render |
| Damp inside behind wall | Water getting in | Investigate before cosmetic work |
If more than one problem shows up, deal with the most serious first. There is little point painting over render that is about to come away from the wall.
Typical costs compared
| Option | Typical guide cost for a semi-detached house |
|---|---|
| Soft wash of rendered walls | £300 to £600 |
| Exterior repaint including preparation | Often £1,800 to £3,600, plus access |
| Patch repairs to render | Often a few hundred to a few thousand pounds |
| Full re-render | Often several thousand pounds, commonly £6,000 or more with scaffold |
These figures are rough guides and vary widely with the size of the house, the render system, access and region. Repainting and re-rendering usually need scaffold, which adds to cost and time.
Access is often the deciding factor. A soft wash can usually be done from the ground on a two-storey house, while repainting and re-rendering almost always need scaffold for the full height of each elevation, which also adds time and disruption.
Why cleaning first makes sense
Growth and dirt can make sound render look much worse than it is. A soft wash often reveals that the paint or render is in better condition than expected, and many owners decide they do not need to repaint after all. If you do still want to paint, cleaning first is essential, because paint applied over algae and mould will not bond well and will fail early.
Cleaning also exposes defects that were hidden under growth, such as cracks and hollow patches, which helps you get accurate quotes for any repairs.
Checking your render yourself
You can learn a lot from a careful look around the house on a dry day. Rub a hand across painted render: chalky white powder means the paint is weathered. Tap suspicious areas lightly with a knuckle or the handle of a screwdriver: a hollow sound means the render may have come away from the wall. Look for cracks around windows and doors, at corners and where extensions meet the main house.
- Staining only, sound surface: soft wash
- Chalky or faded paint, sound render: clean then repaint
- A few small hollow patches: patch repair
- Large hollow areas, wide cracks, bulging: get a renderer or surveyor to inspect
- Damp inside the house: investigate before any cosmetic work
When repainting is the right choice
Repainting is worthwhile when the paint itself has failed: it is badly faded, chalky, patchy or peeling, or you want a different colour. Use a breathable masonry paint suited to the render, and make sure any damp causes such as leaking gutters are fixed first. Painting a previously unpainted through-coloured or silicone render is a bigger decision, because it commits you to repainting in future.
Think about timing too. Painting should be done in dry weather above the minimum temperature on the paint tin, which in the UK usually means late spring to early autumn. A soft wash can be done earlier in the year, giving the walls time to dry fully before painting.
When re-rendering is needed
Re-rendering is a major job and should only be done when the render is failing. Signs include large hollow-sounding areas, wide or spreading cracks, render bulging away from the wall, sections falling off and water getting into the wall behind. On older solid-walled houses, cement render sometimes traps moisture, and replacing it with a breathable lime render may be recommended. Get advice from a renderer or surveyor before committing.
Frequently asked questions
How long does a soft wash last compared with a repaint?
A soft wash typically keeps render clean for several years, with shaded walls regrowing sooner. A good repaint can last ten years or more, but painted render still grows algae and needs cleaning from time to time. The two are not really alternatives: cleaning keeps any render looking good, while painting fixes failed paint or changes the colour.
Can you soft wash render before painting it?
Yes, and it is strongly recommended. Paint needs a clean, sound surface to bond to. Soft washing kills and removes algae and mould so they do not grow back under the new paint. The walls should be left to dry thoroughly before painting, usually for at least a few dry days, and any loose or flaking paint should be scraped off.
Is it worth re-rendering just because render is stained?
Almost never. If the render is sound and only stained, cleaning will restore its appearance for a fraction of the cost. Re-rendering is a large and disruptive job that only makes sense where the render is cracked, hollow, falling off or letting water in. Clean first, then judge the condition before deciding on bigger work.
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