Render doesn’t last forever. Pebbledash from the sixties and seventies is now fifty years old, and the sand-and-cement that went on in the eighties is not far behind. Most of it is at the end of its life, and the question we get asked on nearly every survey is the same one: does this need doing, or can it wait another few years?
Here is what we actually look for, and what each thing tells us.
1. Blown or hollow patches
Tap along the wall with a knuckle or the handle of a scraper. Sound render gives a solid, dull knock. Failed render sounds hollow — the coat has debonded from the wall behind it and is only held on by the render around it. Once you have hollow areas, water is already getting behind the coat, and every frost makes it worse. A few small blown patches can be cut out and made good. When the hollow areas join up, the wall needs stripping.
2. Cracking that follows the structure
Fine, shallow crazing across a panel is usually cosmetic. The cracks that matter are the ones that run in straight lines — down from the corners of windows, along the line of a lintel, or vertically where two different wall materials meet. Those are stress cracks. They mean the original render was never beaded or reinforced for the way the wall moves, and filling them just moves the crack an inch to one side.
3. Paint that will not stay on
If you are repainting every two or three years and it is flaking again within twelve months, the problem is not the paint. Either the render underneath is holding moisture and pushing the paint off from behind, or the surface has broken down and there is nothing left for the paint to key to. Repainting a wall in that state is money spent on a symptom.
4. Damp on the inside walls
Penetrating damp — patches that appear on inside walls a day or two after heavy, wind-driven rain, usually on the weather side of the house — often traces back to failed external render. Water gets through a crack or a blown patch, sits in the wall, and shows up inside. A modern breathable system (silicone, monocouche or lime) fixes this by keeping the water out while still letting the wall dry. Damp that is there all year round, or rises from the floor, is a different problem and needs its own diagnosis.
5. The render is sound but the look is wrong
Sometimes there is nothing structurally wrong. The render is solid, it is not cracked, it is just tired — a grey pebbledash front, or a house that is half brick and half render after an extension and never looked right. That is a legitimate reason to re-render, and it is a smaller job than a strip-out because the substrate is already there. A skim coat of modern through-colour render over sound existing render is a real option, and we will tell you on the survey whether your wall is a candidate.
6. What is underneath
This is the one you cannot check yourself, and it is the reason we survey rather than quote over the phone. Pebbledash hides the state of the brickwork and the pointing. Until a test area is off, nobody knows whether the substrate needs significant repointing or is sound. A quote that does not mention the substrate is a guess, and the guess is usually optimistic.
Repair, re-skim, or full replacement
| What we find | Usually means |
|---|---|
| A few isolated blown patches, rest sound | Cut out and make good |
| Sound render, dated finish | Re-skim in modern through-colour render |
| Widespread hollow areas or structural cracking | Strip back to substrate and re-render |
| Failed render plus damp inside | Strip, repair substrate, breathable system |
What happens if you leave it
Failed render is not a finish problem, it is a weather problem. Every winter that water sits in the wall, the frost does a bit more damage to the brick and the pointing behind it. The job does not get cheaper by waiting, because the substrate repair bill grows. The houses that cost the most to put right are the ones where the render was left another five years.
Before you accept a quote
Ask what happens to the existing render, what beading and mesh is included, and what the warranty actually covers. If your render is sound and only needs a re-skim, a firm quoting you for a full strip-out is overselling. If your render is blown across three elevations and a firm is quoting to patch and paint it, they are underselling — and you will be paying twice.
