Rendering in Winterborne Stickland

Lime render. The right answer on anything solid walled and old. Two or three coats of lime, hair gauged in the base, worked well into the background and kept damp and covered while it cures. It is soft, breathable and forgiving of a wall that moves a little, which is exactly what a mixed background needs. Finished with a float or limewash rather than a modern paint.

Reinforcing across a change of background. Where flint meets brick, or cob meets a plinth, the two sides take up water differently and move differently. A mesh or a scrim bedded across the junction spreads that movement instead of letting it concentrate in one line, and it is the single detail that decides whether the crack comes back.

Taking hard render off. Cement on an old wall comes off by hand and in sections, because the wall behind it is softer than the coat and a breaker takes both. Tapping first tells us how much of it has already parted from its background.

Silicone thin coat and monocouche. Primer, a polymer basecoat with mesh through it, then a through-coloured silicone topcoat scraped back, or a single thick monocouche coat. These belong on the modern houses, the extensions and blockwork outbuildings, with beads, stop ends and a bellcast at the base. They do not belong on an old solid wall.

Sand and cement, pebbledash and Tyrolean. Where the background suits it, a scratch and float coat with a dry dash thrown on green or a Tyrolean flicked on is a straightforward repair. Matching an existing dash is aggregate size and colour, so a sample panel goes up first.

Cracking, delamination and staining. Fine crazing is shrinkage and cosmetic. A straight crack that follows a line across a wall is telling you about the wall rather than the render. Green algae and black staining come off a sound coat with a soft wash and never with pressure.

Render over external wall insulation. Board fixed as a render carrier, then mesh, basecoat and topcoat over it, with Approved Document L setting what a renovated wall should reach. It is a good job on modern construction and the wrong one on a breathable old wall, and we will say which yours is.

No rate per square metre, because the square metres are the easy part; what is already on the wall decides the price.

Getting to it. A cottage on the village street with no room for a lorry, a farmhouse with a yard beside it and a modern house on the edge of the village are three different platforms before any material arrives. A bungalow gable comes off a tower, a three storey elevation wants a scaffold, and the platform has to stand for the whole system rather than a day. The work at height rules are why it is a priced line rather than something folded into a rate.

What is already on the wall. Rendering over sound brick is one job. Hacking off blown sand and cement, or a pebbledash that has parted from the background, is another, and it is the part nobody can see from the road. We tap the whole elevation before quoting, because the hollow areas set the hours.

The system, and what the wall behind it needs. Silicone thin coat over insulation, monocouche through-coloured, or traditional sand and cement all price differently and behave differently. On a solid wall that has to breathe, a plastic-rich modern system traps moisture and moves the problem inside, so the right system is a wall decision rather than a colour decision.

Comparing quotes? Ask which system is being quoted and how many coats, whether the old render is being hacked off or overlaid, whether beads, bellcast and stop ends are included, whether the scaffold is in the price, and what happens to the existing sills and pipework. Two quotes for the same job are usually two different jobs.

Walls in these valleys were built from what was to hand, which is why so many of them are layered: flint rubble with brick bands and brick at the corners and openings, cob raised off a stone or brick plinth to keep it out of the wet, and a century of later patching in whatever was cheapest at the time. Each of those materials pulls water out of a fresh coat at a different rate, holds it for a different length of time and moves a different amount with heat and damp. Render is a thin rigid skin over the top of all that, so the strain concentrates exactly where one material meets another.

That is why the classic failure here is not a random crack but a straight one, running horizontally along a plinth line or vertically down beside a brick quoin. Filling it achieves nothing, because the movement underneath has not changed. What works is preparing each background properly rather than uniformly, controlling the suction so the coat cures evenly across the whole wall, and bedding mesh across every change of material so the movement is spread over a width instead of concentrated in a line. It is slower and it shows on a quote as preparation rather than as render. If a price for an old mixed wall does not separate those out, it has been measured off the road.

We cover Winterborne Stickland, Winterborne Whitechurch, Turnworth, Milton Abbas and the villages towards Blandford, broadly DT11, with Dorset Council for planning and building control. You are dealing with Bournemouth Roofing & Building, the trading name of Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.