Will cleaning make my render look newly painted?

It will remove growth and restore much of the original colour, but it cannot restore a coating that has chalked or faded through UV exposure.

Can I paint over algae if I use a good paint?

No. The growth continues under the film and comes back through, usually within a couple of years. Clean and treat first.

Do you repaint render?

We are exterior cleaners, so we clean and treat and tell you honestly if we think the coating rather than the growth is the problem.

Does cleaning damage existing masonry paint?

Softwashing at low pressure does not damage sound coatings. Paint that is already failing may lift, which reveals the condition rather than causing it.

Clean Render or Repaint It?

When a rendered house starts looking tired the two obvious options are to clean it or to paint it, and they are often presented as alternatives. In practice they answer different questions. Cleaning removes what is growing on the surface. Painting replaces a coating that has reached the end of its life. If the render is discoloured by algae, cleaning is the answer and painting is an expensive way to hide a problem that will grow back through. If the coating itself is chalky, patchy or failing, cleaning alone will leave you with clean, tired paint.

Diagnose what you are actually looking at

Green, black or orange discolouration, worse on the shaded and sheltered faces and worse near gutters and ground level, is biological growth. Uniform fading across a whole elevation including the sunny side, powdery residue on your hand when you rub it, or paint flaking and blistering, is coating failure. Many houses have both, which is why the order of work matters.

This guide sits under our Wall Cleaning & Softwash work, covering 20-mile radius of Plymouth.

The case for cleaning only

If the coating is sound and the problem is growth, a softwash clean returns the wall close to its original appearance for a fraction of what painting costs, with no scaffolding and no colour decisions. It is also reversible in the sense that you have not committed to a coating system you will need to maintain forever. Most tired-looking rendered houses in this area need cleaning rather than paint.

The case for repainting

Where a coating is chalking, patchy from previous repairs, or where hairline crazing needs bridging, a proper masonry coating restores a consistent finish and adds a protective layer. It is also the moment to change colour. The important thing is to accept that paint is a maintenance commitment: it will need doing again, and the seaward elevation will need it sooner.

Why cleaning comes first either way

Coating over live algae is one of the most common causes of a paint job that looks poor within two years. The growth continues under the film, the film loses adhesion in those areas, and the discolouration comes back through. Any competent repaint starts with a clean, a biocidal treatment and proper drying time. If a decorator does not mention this, ask.

Breathability matters more than brand

Render works by letting moisture move through it. An impermeable coating traps water in the render and the wall behind, and over successive winters that is how sound render starts blowing off in sheets. Breathable mineral or silicone-based masonry coatings are the right family of products for render, particularly on older solid-wall properties.

Repairs before either option

Cracks, hollow areas and blown patches should be dealt with before cleaning or coating. Cleaning a wall with an unrepaired crack drives water into it. Painting over a hollow patch simply gives you a painted hollow patch. If a survey shows significant defects, that is a rendering job and the cosmetic work follows it.

Cost and disruption compared

Cleaning is typically a one or two day job with no scaffolding on most houses and nothing to decide beyond the date. Painting involves preparation, access, weather dependency across several days, and a colour choice you live with for years. We will not quote a paint job as an exterior cleaner, but we will tell you honestly which one we think your wall needs.

How to decide in five minutes

Rub a dry hand firmly on the render in a shaded area and then in a sunny one. Chalk on your hand from both means the coating is spent. Green transfer means growth. Look at whether the discolouration follows water paths and shade, which points to cleaning, or covers everything evenly, which points to paint. Photograph both areas and send them to us if you want a second opinion.

Reader note: Clean the render or repaint it?

Owner deciding between a clean and a full repaint of rendered walls.

Diagnose what you are actually looking at: Green, black or orange discolouration, worse on the shaded and sheltered faces and worse near gutters and ground level, is biological growth. Uniform fading across a whole elevation including the sunny side, powdery residue on your hand when you rub it, or paint flaking and blistering, is coating failure. Many houses have both, which is why the order of work matters. The case for cleaning only: If the coating is sound and the problem is growth, a softwash clean returns the wall close to its original appearance for a fraction of what painting costs, with no scaffolding and no colour decisions. It is also reversible in the sense that you have not committed to a coating system you will need to maintain forever. Most tired-looking rendered houses in this area need cleaning rather than paint. The case for repainting: Where a coating is chalking, patchy from previous repairs, or where hairline crazing needs bridging, a proper masonry coating restores a consistent finish and adds a protective layer. It is also the moment to change colour. The important thing is to accept that paint is a maintenance commitment: it will need doing again, and the seaward elevation will need it sooner. Why cleaning comes first either way: Coating over live algae is one of the most common causes of a paint job that looks poor within two years. The growth continues under the film, the film loses adhesion in those areas, and the discolouration comes back through. Any competent repaint starts with a clean, a biocidal treatment and proper drying time. If a decorator does not mention this, ask. Breathability matters more than brand: Render works by letting moisture move through it. An impermeable coating traps water in the render and the wall behind, and over successive winters that is how sound render starts blowing off in sheets. Breathable mineral or silicone-based masonry coatings are the right family of products for render, particularly on older solid-wall properties. Repairs before either option: Cracks, hollow areas and blown patches should be dealt with before cleaning or coating. Cleaning a wall with an unrepaired crack drives water into it. Painting over a hollow patch simply gives you a painted hollow patch. If a survey shows significant defects, that is a rendering job and the cosmetic work follows it. Cost and disruption compared: Cleaning is typically a one or two day job with no scaffolding on most houses and nothing to decide beyond the date. Painting involves preparation, access, weather dependency across several days, and a colour choice you live with for years. We will not quote a paint job as an exterior cleaner, but we will tell you honestly which one we think your wall needs. How to decide in five minutes: Rub a dry hand firmly on the render in a shaded area and then in a sunny one. Chalk on your hand from both means the coating is spent. Green transfer means growth. Look at whether the discolouration follows water paths and shade, which points to cleaning, or covers everything evenly, which points to paint. Photograph both areas and send them to us if you want a second opinion.

Questions we get on this

Will cleaning make my render look newly painted?: It will remove growth and restore much of the original colour, but it cannot restore a coating that has chalked or faded through UV exposure.
Can I paint over algae if I use a good paint?: No. The growth continues under the film and comes back through, usually within a couple of years. Clean and treat first.
Do you repaint render?: We are exterior cleaners, so we clean and treat and tell you honestly if we think the coating rather than the growth is the problem.
Does cleaning damage existing masonry paint?: Softwashing at low pressure does not damage sound coatings. Paint that is already failing may lift, which reveals the condition rather than causing it.

If this describes your situation

Send a photo of a shaded and a sunny wall and we will tell you which of the two jobs you actually need.

Send photos for a quote Wall Cleaning & Softwash Call 07830 242403

Clean the render or repaint it?