What external rendering and facade repair covers
Facade work covers a wider range than a single re-render, and most of what we're asked to do falls into one of a few categories. Full re-rendering strips the existing coat back to brick or block and applies a new system across the whole elevation, usually where the existing render has failed extensively or where a property is being upgraded as part of a wider refurbishment. Patch and crack repair deals with localised failure, hairline cracking, a section blown loose from the wall, or damage around a downpipe or bracket, without disturbing sound render elsewhere on the elevation. Re-rendering after damp issues is its own category, since removing a hard cement render that's been trapping moisture behind it and replacing it with a more breathable specification is as much a damp remedy as a cosmetic job. Facade cleaning and repainting refreshes existing sound render with masonry paint rather than replacing the render itself, which suits a render system that's structurally fine but has become dirty, algae-stained or simply dated in colour. Pointing and detailing around window and door reveals is often the weak point on an otherwise sound elevation, since these junctions move slightly with the building and are where poorly detailed render tends to crack first. We survey the elevation before recommending which category a project falls into, since a full re-render is sometimes unnecessary where targeted repair and a repaint would do the job at a fraction of the cost.
What drives the cost of rendering work
Render pricing depends on access and area more than most people expect. Scaffolding is usually needed for anything beyond ground floor level, and a full terrace elevation on a three-storey Victorian house costs considerably more to scaffold than a single-storey rear extension, so access sometimes ends up being a larger line item than the render itself on a modest repair. Substrate condition is the next major factor: removing failed cement render down to brick, especially where it's been on the wall for decades and is well bonded in places, takes far longer than applying render to a clean, sound background, and a wall with historic patch repairs in mismatched materials sometimes needs more preparation than a wall that's never been touched. Render system choice affects both material and labour cost, monocouche and silicone renders are typically applied in fewer coats than traditional sand and cement with a separate top coat, which affects labour time, though material cost per bag or per square metre varies the other way. Detailing adds cost too: window and door reveals, string courses, decorative mouldings and downpipe brackets all need cutting in around carefully rather than rendering in one flat pass, and a plain elevation renders faster than one with a lot of period detailing to work around. As a general guide, a single-storey rear extension elevation might be scaffolded, prepared and rendered within a week to ten days, while a full three-storey terrace elevation with substantial preparation typically runs two to three weeks once curing time between coats is factored in. Labour tends to be the larger share of the cost on a heavily prepared wall, since stripping decades-old cement render safely without damaging the brick behind it is slow, careful work, whereas material cost dominates more on a straightforward re-render over a sound, already-prepared substrate. We price rendering work after a proper survey of the elevation and substrate, broken down by scaffold, preparation, render system and detailing, rather than a blanket rate per square metre that doesn't reflect what a specific wall actually needs.
Render systems compared: sand and cement, K Rend, monocouche and lime
Traditional sand and cement render is applied in two or three coats, a scratch coat, a floating coat and sometimes a setting coat, and finished with a texture such as a wood float, scraped or roughcast finish, then usually painted. It's a well-understood, relatively affordable system, but it's rigid and prone to cracking if the mix ratio is wrong for the background or if it's applied too thickly in one pass. K Rend and other silicone renders are polymer-modified, factory-mixed systems applied over a base coat and mesh, and they're more flexible and crack-resistant than sand and cement, with colour built into the render itself rather than relying on paint, which means the colour doesn't need repainting every decade in the way a painted cement render does. Monocouche render is a single-coat, through-coloured system applied in one pass over a mesh-reinforced base, and it's popular on newer builds and extensions for speed of application, though it needs the right weather conditions and a skilled hand to avoid an uneven, patchy finish. Lime render is the traditional specification for solid-wall period properties and behaves quite differently to the modern systems: it's breathable, allowing moisture to pass through and evaporate rather than trapping it, and it flexes slightly with the building's natural movement rather than cracking. We specify the system to suit the wall it's going onto rather than defaulting to one product across every job, since the wrong render on the wrong substrate is one of the most common causes of render failure we're called out to fix.
Render and damp on Victorian solid-wall properties
A large proportion of the render repair we're called out for on Victorian and Edwardian houses traces back to the same underlying issue: a hard cement render applied to a solid brick wall that was never designed to be sealed in that way. Solid walls, common in London terraces built before cavity construction became standard in the 1920s and 30s, rely on being able to absorb and release moisture through the wall itself. A modern cement render, particularly one applied at a rich mix ratio with little lime content, is far less permeable than the brick behind it, and once moisture gets in, through a crack, a poorly detailed reveal or rising damp at the base of the wall, it can't easily evaporate back out through the render. Instead it tracks sideways or gets pushed further into the wall, sometimes showing up as damp patches on internal plaster well away from the original point of failure. This is why re-rendering a Victorian solid wall after a damp problem often means specifying a lime-based render, typically an NHL 3.5 or similar hydraulic lime mix, rather than simply replacing like-for-like with the cement render that likely contributed to the problem in the first place. Where we're asked to deal with damp linked to render on a solid wall, we'd typically expect the sequence to run: confirm the wall is genuinely solid rather than an unrecognised cavity, remove the render causing the problem, allow the wall to dry out for a period before re-rendering, and then apply a breathable lime specification rather than rushing straight back to a like-for-like cement finish. Skipping the drying period is a common shortcut that undermines an otherwise correct specification, since re-rendering over a wall that's still saturated just traps the existing moisture behind the new coat rather than solving anything. Lime render isn't a universal fix for every damp issue, and where the underlying cause is a specific defect such as a failed damp proof course or a blocked cavity tray, that needs addressing on its own terms, but on a genuinely solid-wall property, breathability is usually the right starting principle for whatever render goes back on.
Render and External Wall Insulation (EWI)
External Wall Insulation systems, increasingly common on solid-wall Victorian and ex-council properties looking to improve thermal performance, change how the render on a wall needs to be specified and detailed. EWI involves fixing rigid insulation boards to the outside of the wall, then applying a reinforced base coat with mesh embedded into it, followed by a top coat, usually a silicone or acrylic render, rather than rendering directly onto brick. Where we're asked to re-render a wall that already has EWI installed, or to repair render that's failed on an EWI system, the detailing at openings matters more than on a solid masonry wall, since window and door reveals, meter boxes and pipe penetrations all need the insulation and render built up correctly around them to avoid a thermal bridge or a point where water can track behind the system. Reveal depth changes too, since adding insulation and render to an external wall typically adds 80 to 150mm of thickness depending on the insulation used, which affects how windows, door thresholds, cills and rainwater goods need to be extended or re-detailed to sit properly against the new wall face. We don't design or specify EWI insulation systems as a standalone service, but where render work is needed on a wall with EWI already fitted, or as part of a wider EWI installation being coordinated by others, we work to the system manufacturer's detailing requirements so the render performs and weathers as the system was designed to.
Conservation areas and planning considerations for render
Render is often the single biggest visual element of a street-facing elevation, which is exactly why conservation areas and Article 4 directions frequently place restrictions on changing it. In many conservation areas, painting over previously unpainted render, or changing the render colour on the principal elevation, from a natural sand and cement finish to a bright modern colour for example, can require planning permission even though the same change would be permitted development on an unlisted property outside a conservation area. Some councils also restrict changing render texture or replacing traditional lime or sand and cement render with a modern silicone or monocouche system on street-facing elevations, since the visual character of a terrace often depends on a consistent render finish across neighbouring properties. Listed buildings carry stricter controls again, and render specification on a listed property, including colour, texture and material, is very likely to need listed building consent regardless of how minor the change looks in practice. On a terrace of uniformly rendered Victorian or Edwardian houses, render finish and colour often forms part of what gives the street its character as a whole, which is one of the main reasons conservation area controls focus on it specifically rather than on less visible changes. Where several neighbouring properties have already changed their render finish or colour without consent, that doesn't necessarily set a precedent that makes a similar change acceptable for your property, since councils can and do take enforcement action retrospectively, so it's worth checking the current position for your specific address rather than assuming what's already been done nearby is a reliable guide. We flag at survey stage where a property's location is likely to bring render work into scope for planning or listed building consent, but confirming the position and making any application is a separate process handled by the property owner, or an architect or planning consultant working on their behalf, rather than something we apply for on the client's part.