Rendering in West Lulworth

Silicone thin coat. Primer, a polymer basecoat with glass fibre mesh bedded through it, then a through-coloured silicone topcoat scraped to an even texture. It is water shedding, it flexes slightly and it stays cleaner than most finishes. On an exposed elevation the basecoat goes on at full thickness with the mesh properly buried, because a thin base is where these systems fail.

Monocouche. A single through-coloured coat put on thick and scraped back the next day. Hard wearing, and it wants a sound background and a settled spell of weather. Onshore wind and rain during the first few days is not a settled spell, so on the seaward side we plan it carefully or use something else.

Sand and cement, pebbledash and Tyrolean. Scratch coat, float coat, then a smooth face, a dry dash thrown on green, or a Tyrolean flicked on. The dash finishes here have lasted well because they are thick and rough, which sheds water. Matching a patch means matching aggregate size and colour, so a sample panel goes up first.

Lime render on the old walls. Solid rubble stone and old brick walls have no cavity and get rid of rain by drying out through their own face. They need lime, two or three coats, hair gauged in the base. Sealing one with a cement or acrylic coat traps the moisture and moves the damp indoors, which on this coast happens quickly.

Tapping and hacking off. Blown render has parted from its background. We tap the whole elevation and mark the hollow areas, and on a weather wall those areas are usually wider than they look, because water has been travelling behind the coat rather than sitting where it got in.

Cracks, delamination, algae and staining. Fine crazing is shrinkage. An open crack on an exposed elevation is an entry point and wants cutting out and reinforcing rather than filling. Green and black staining on a shaded wall comes off with a soft wash, not a pressure lance.

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 is expected to reach. On an exposed elevation the edges and the base detail decide whether it lasts, so that is where our quote gets specific rather than where it goes vague.

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 stone cottage on the village street, a bungalow above the cove and a two storey house facing the weather are three different platforms, and on this coast the wind decides how long one can safely stand. 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.

How much wind driven rain a wall gets is measurable, and it is the reason two identical houses can need different render specifications. The method for assessing exposure of walls to wind driven rain is a British Standard, and the short version is that exposure comes from how much rain falls, how hard the wind blows it and how sheltered the wall is by ground and buildings around it. Half a mile from open water with the prevailing weather coming straight in off the sea, a south west facing gable here is in a different category from a sheltered wall inland, and it needs to be treated like one.

What changes in practice is the build up rather than the brand. A thicker basecoat with the mesh properly buried instead of skimmed over. Beads and stop ends at every opening rather than render run tight to a frame. A bellcast at the base so water leaves the wall instead of tracking behind it. Cills with a proper drip so rain is thrown clear rather than run back under. And on the most exposed elevation, a finish with some texture to it, because a rough face sheds water better than a polished one. It costs more on that one wall than on the other three. That is the correct answer, and any quote that prices all four elevations identically has not looked at which way the house faces.

We cover West Lulworth, East Lulworth, Winfrith, Wool and the villages along the Purbeck coast, broadly BH20, 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.