In short
- Silicone render is a thin-coat system: a meshed base coat, a primer and a 1–2 mm through-coloured silicone topcoat.
- It sheds rain, lets water vapour escape and does not need painting. Expect a life of 25 years or more with occasional cleaning.
- Published 2026 UK ranges run from about £60 to £120 per m² installed; Surrey quotes usually sit in the upper half.
- The finish is only as good as the base coat and the detailing around windows, sills and the damp-proof course.
What silicone render is
Silicone render is a family of thin-coat finishes in which silicone resin is added to the binder. The silicone makes the surface hydrophobic, so rain beads and runs off rather than soaking in, while the render stays vapour-permeable, so moisture inside the wall can still escape. The colour is mixed through the material in the factory. Nothing is painted on afterwards.
It is not a single coat. A proper silicone system is a build-up of layers, each with a job, and the topcoat you see is the thinnest part of it. Our render system build-up guide explains each layer.
How a silicone system is installed
- The wall is assessed: existing render tapped for hollow areas, cracks mapped, damp investigated and the damp-proof course located.
- Loose or hollow render is removed and the substrate made good. Sound pebbledash or render can sometimes be kept and levelled.
- Stainless steel or PVC beads are fixed at corners, reveals and the base of the wall, stopping the render above the damp-proof course.
- A base coat is applied with alkali-resistant glass-fibre mesh embedded in it to spread stress and resist cracking.
- Once the base has cured, a primer tinted to the finish colour is applied.
- The silicone topcoat is trowelled on and floated to its texture, usually a 1 mm or 1.5 mm grain.
The number of days between stages depends on temperature and humidity. Installers should not apply silicone below about 5°C, in rain, or in strong direct sun. See the best time of year to render.
Where silicone render suits Surrey homes
Silicone is a strong choice for the brick and blockwork houses that make up most of Guildford's suburbs, from 1930s semis in Merrow and Stoughton to 1970s estates in Burpham and Goldsworth Park in Woking. It is widely used over external wall insulation and on new extensions where you want the extension to match a re-rendered house.
It is not the right answer for every wall. Solid-walled cottages built before about 1919, common in Godalming, Farnham and the Surrey Hills villages, generally need a lime-based finish that works with the wall rather than against it. Read rendering period and solid-wall homes before choosing.
What silicone render costs in 2026
| Item | Typical 2026 range |
|---|---|
| Silicone thin-coat system, supplied and applied | £60–£120 per m² |
| Scaffolding, two-storey semi | £800–£2,500 |
| Removing failed render | around £10 per m² plus skip |
| Three-bed semi, whole house | roughly £7,000–£11,000 |
These are published UK market ranges, not quotations. London and the South East typically price 15 to 25 per cent above the national average, and the condition of your substrate moves the figure more than anything else. Our 2026 rendering cost guide breaks the numbers down.
Silicone compared with the alternatives
Silicone costs more than monocouche and sand and cement, and it earns that through lower maintenance and better resistance to algae staining. On a north-facing elevation under trees it will stay cleaner for longer, although no render is permanently algae-proof. Our silicone vs monocouche comparison sets out when the cheaper option is the better one.
Questions people ask
Does silicone render need painting?
No. The colour runs through the topcoat. It may need a gentle clean every few years, particularly on shaded walls, but it should not be painted unless a matching silicone paint is used to change the colour.
Can silicone render go over pebbledash?
Often, yes, if the pebbledash is well bonded. It needs a levelling base coat with mesh first. Hollow or loose pebbledash has to come off. See rendering over pebbledash.
Is silicone render the same as K-Rend?
No. K-Rend is a brand. Kingerlee, which makes K-Rend, sells silicone thin-coat renders as well as thicker silicone-enhanced scraped renders. See K-Rend vs Weber.
How long does silicone render last?
Manufacturers commonly quote 25 to 30 years or more for a correctly installed system. Life depends on detailing, exposure and whether the base coat was built properly.
Why has my silicone render gone green?
Silicone contains biocides that slow algae growth, but they leach out over years, and shaded, damp walls will eventually colonise. It can be cleaned with a biocidal wash. See cleaning silicone render.