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How is damaged render repaired, and when is a patch enough?

Small cracks and hollow patches in render can usually be cut out and repaired to match the wall. When damage is spread across an elevation, or water has got behind it, stripping and re-rendering that wall is often the longer-lasting fix.

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By the QuoteZila editorial team. Editorial policy.

What kinds of render damage are there?

Render fails in a few recognisable ways. Each points to a different repair:

  • Hairline crazing. A fine web of surface cracks. Often cosmetic, and usually dealt with by a suitable masonry paint or filler.
  • Open cracks. Wider cracks that let rain in, often running from the corners of windows and doors. These need cutting out and filling.
  • Hollow or blown patches. Render that has lost its grip on the wall and sounds drummy when tapped. These need cutting back to firm render and patching.
  • Crumbling at the base. Render that runs down to the ground or into a path can stay wet and break up. A bead at the bottom edge helps the repair last.
  • Damage round fixings. Satellite dishes, cables, hanging baskets and old brackets can crack the render around their screws.
  • Staining. Streaks from leaking gutters or overflows, which point to a separate fault that needs fixing too.

QuoteZila is starting in Cheshire, with Crewe, Nantwich and Sandbach among the first towns, and anyone in the UK can post a job. This page helps you work out what kind of repair to ask for.

How do you tell a patch job from a re-render?

Walk round the house and tap the render with your knuckles, low down and around the windows. Mark hollow areas in chalk. Then look at the whole wall.

A patch usually makes sense when:

  • The damage is in one or two clear places.
  • The rest of the render is firm and well bonded.
  • The cause is obvious and can be fixed, such as a leaking gutter.

A full re-render of that wall is often better when:

  • Hollow areas are spread across much of the elevation.
  • The render is soft, sandy or comes away in your hand.
  • The wall behind has been wet for a long time.
  • The wall has been patched many times already.

There is a rules point too. The Planning Portal says that where 25 per cent or more of an external wall is re-rendered, building regulations would normally apply and the thermal insulation would normally have to be improved [S3]. A large repair can tip into that, so ask the renderer how much of the wall they expect to replace. GOV.UK explains when you need building regulations approval.

Why does matching the finish matter?

A repair that looks different draws the eye to it. Matching means getting the same coats, texture and colour as the render around it. That is easier with a plain painted render than with a pebble dash, a scraped through-coloured render or an old textured finish.

It also matters for planning. The Planning Portal says replacing existing render with render of a similar appearance does not need planning permission, but changing the type or colour is likely to change the external appearance of the house, and then permission will be required [S2]. In a conservation area, check with the council before work starts.

What should be fixed before the render?

A render repair will not last if water keeps reaching the wall. Before the renderer starts, look at:

  • Gutters and downpipes, which can soak a wall if they leak or overflow.
  • Window sills, which should throw water clear of the wall below.
  • Ground levels, so soil and paths do not sit against the render.
  • Cracks in the wall itself. A crack that runs through the brick or block behind the render, or keeps reopening, may need a builder or a structural engineer to look at it first.

What should you ask a renderer?

Ask each renderer the same questions:

  • How much render will you cut out, and how will you find the edges of the damage?
  • Which render will you use, and will it suit what is already on the wall?
  • How will you match the texture and colour?
  • Will the wall need painting afterwards, and is that in the price?
  • What access will you use? HSE says work at height means any place where, without precautions, a person could fall a distance liable to cause injury [S4]. HSE explains this on its work at height questions page.
  • What will you do if the wall is worse than expected once the render is off?

Citizens Advice says to get written quotes, not verbal ones, and to check whether the price includes VAT [S5].

HSE: work at height. QuoteZila is not affiliated with this organisation.

Jobs you might post

These are examples, not taken from real job posts.

  • "Two hollow patches of render on the side wall, each about the size of a door. Please quote to cut out, patch and paint the wall."
  • "Cracks running from the corners of the front windows. Looking for a renderer to repair and match the finish."
  • "Render crumbling at the bottom of the back wall where it meets the patio. Please quote to repair and fit a bead."

Get quotes for render repair

Describe the damage, where it is, how big it is and the finish on the wall now, with photos if you can. Up to five matched local businesses can send you a quote [QZ2]. QuoteZila is free for customers and local businesses [QZ1].

Honest status: QuoteZila is new. We're starting in Cheshire, beginning with Crewe, Nantwich and Sandbach, and growing area by area. Anyone in the UK can still post a job or register a business. How fast you get quotes depends on how many local businesses have joined near you. Businesses can register and receive jobs straight away. We don't check insurance, qualifications or registrations, so please check these yourself before you hire.

Posting a job is not open yet

See our plasterers page and builders page. For prices, see what changes the cost of rendering. For background on the most common render, see sand and cement render.

Questions about render repair

Can you repair just part of a rendered wall?

Yes. A renderer cuts the damaged area back to sound render, prepares the edges and builds the patch back up in matching coats. The hard part is matching the texture and colour, so ask how they will blend it and whether the wall will need painting afterwards.

Will a render patch show?

It may, at least at first. New render can dry a different shade, and a smooth patch on a textured wall stands out. Painting the whole elevation after the repair is a common way to even it out. Ask to see a similar repair the renderer has done.

Do I need permission to repair render?

Usually not for like-for-like repair. The Planning Portal says repairs and maintenance do not need a planning application, but a listed building needs listed building consent for significant works. Changing the type or colour of render can need planning permission.

When does a render repair become a full re-render?

When hollow or cracked areas are spread across most of the wall, when the render is soft or crumbling, or when water has been getting behind it for a long time. The Planning Portal says re-rendering 25 per cent or more of an external wall normally brings in building regulations.

Does QuoteZila check the renderers who quote?

No. We don't check insurance, qualifications or registrations, so please check these yourself before you hire. You can report a quote or a business from your job page.

This page is general information, not professional or legal advice. QuoteZila does not check Gas Safe, WaterSafe, NFRC, NICEIC or other registrations against the register on your behalf: look them up yourself.

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Sources

  1. QZ1: QuoteZila product fact. QuoteZila home and FAQ copy.
  2. QZ2: QuoteZila product fact. QuoteZila FAQ How does getting quotes work.
  3. S1: External walls: planning permission, Planning Portal. Accessed 2026-11-01. https://www.planningportal.co.uk/permission/common-projects/external-walls/planning-permission/
  4. S2: Do I need planning permission to render the outside of my house?, Planning Portal (Interactive House FAQ). Accessed 2026-11-01. https://interactive.planningportal.co.uk/faqs/do-i-need-planning-permission-to-render-the-outside-of-my-house
  5. S3: External walls: building regulations, Planning Portal. Accessed 2026-11-01. https://www.planningportal.co.uk/permission/common-projects/external-walls/building-regulations/
  6. S4: Work at height: frequently asked questions, HSE. Accessed 2026-11-01. https://www.hse.gov.uk/work-at-height/faqs.htm
  7. S5: Before you get work done on your home, Citizens Advice. Accessed 2026-11-01. https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/before-you-get-building-work-done/